Cold Form Toughness CIDECT-1B-2_03

NOTCH TOUGHNESS OF COLD FORMED HOLLOW SECTIONS

FINAL (REVISION 2) REPORT TO CIDECT ON PROGRAMME 1B

By: N. Kosteski

J.A. Packer

R.S. Puthli

CIDECT Report 1B-2/03

October 2003

1 Introduction

In the wake of the surprising brittle fractures sustained during the Northridge, California (1994) andKobe, Japan (1995) earthquakes, requirements for notch tough weld filler metal have been made moreexplicit in many welding codes. Of the welding consumables specified for structural applications with aCharpy V-Notch (CVN) rating, most meet 27 Joules at -29 °C or -18 °C (AWS 2002). However, in aweld Heat Affected Zone (HAZ) the in-situ notch toughness will be a result of the weld filler metal, thebase metal and the welding procedure. Although Welding Procedure Specifications (WPSs) can bewritten such that a demonstrated Charpy V-Notch (CVN) test value must be achieved at a particularlocation, there is often little information available to the structural engineer concerning the inherentnotch toughness of the base metal itself. AWS (2002) reports that steel wide flange (I) sections andstructural steel plates have recently been surveyed in the U.S., at the request of mill producers, in orderto … “show that CVN [Charpy V-Notch] testing of base metal was unnecessary for most buildingapplications”. Charpy V-Notch (CVN) test values of 20 Joules or higher at +4 °C were reported (AWS2002). These surveys have not included manufactured hollow structural steel sections and moreover itis important to note that test values relate to the location in the cross-section where the governingspecification stipulates the test coupon be taken, which may be very favourable. In fact there is even aprecaution given by AWS (2002) for ASTM A500 (cold-formed) hollow sections: “Products

Notch Toughness of Cold Formed Hollow Sections

N. KosteskiDepartment of Civil Engineering, University of Toronto, Canada.Department of Steel and Light Metal Structures, University of Karlsruhe, Germany

J.A. PackerDepartment of Civil Engineering, University of Toronto, Canada.

R.S. PuthliDepartment of Steel and Light Metal Structures, University of Karlsruhe, Germany

Abstract: Since the Northridge and Kobe earthquakes in the 1990s, with their numerous brittlefractures of steel members and welded connections, there is much more awareness of material notchtoughness for all applications where dynamic loading is a design condition. As a result, there has beenrenewed attention directed at assessment of the notch toughness of steel sections, along with tighteningof requirements for welding consumables in welded joints. This report documents the Charpy V-Notch(CVN) toughness of contemporary Rectangular Hollow Sections (RHS) manufactured by companies inNorth America, South America and Europe. The hollow sections were produced as: hot-formed RHSand CHS (Circular Hollow Sections); cold-formed RHS (electric resistance welded); and cold-formedplus stress-relieved RHS (electric resistance welded). Also, the range of parameters included in theexperimental study included specimen orientation (longitudinal versus transverse), cross-sectionlocation (flats, corner, and weld seam), and face exposure (interior face of tube versus exterior face). Intotal, 557 CVN specimens have been impact tested. A surprising difference in notch toughness wasfound between manufacturers and between production processes. Moreover, the notch toughnessmeasured away from the position and orientation stipulated by specifications (the flat face location inthe longitudinal direction) was often very much lower.

2

manufactured to this specification may not be suitable for those applications such as dynamically loadedelements in welded structures, etc., where low-temperature notch toughness properties may beimportant. Special investigation or heat treatment may be required if this product is applied to tubular T-, Y-, and K-connections”. It is this concern that the research reported herein has sought to investigate.

1.1 Brittle fractureBrittle fracture is a catastrophic failure in which a crack will propagate at extremely high speeds withoutwarning. Brittle fractures occur with little or no elongation or reduction in area and with very littleenergy absorption.

Under conditions of low temperature, rapid loading and/or high constraint (e.g., when the principalstresses σ1, σ2, and σ3 are nearly equal) a normally ductile material, such as structural steel for example,may exhibit brittle behaviour.

1.2 Notch toughnessThe conventional toughness of a material is defined as the ability of a smooth (unnotched) member toabsorb energy, usually when loaded slowly (quasi-statically) under uniaxial tension. Alternatively, thenotch toughness is defined as the ability of a material to absorb energy (usually loaded dynamically) inthe presence of a flaw (notch).

The fabrication of a structure will inevitably introduce some type of notch, flaw, discontinuity, orstress concentration. Thus, the notch toughness of a material is a useful property. Notch toughness ismeasured with a variety of test specimens; one of the most widely used is the Charpy V-Notch (CVN)impact specimen. The low cost and simplicity of the Charpy impact test have made it a commonrequirement in international codes and standards for critical structures such as pressure vessels andbridges.

1.3 Charpy V-Notch (CVN) toughness propertiesAs detailed in ASTM E23 (1998), the Charpy V-Notch (CVN) test uses a standard 10x10x55 mmrectangular beam-type specimen (shown in Figure 1) with a machined notch of specified geometry. Atest machine with a pendulum (shown in Figure 2) is used to impact the specimens at varioustemperatures. The absorbed energy required to fracture the specimen can be ascertained as a function ofthe test specimen temperature. A typical Charpy V-Notch (CVN) toughness versus temperature curvefor mild structural steel, under both static and dynamic loading, is shown schematically in Figure 3.

By plotting the CVN toughness as a function of temperature, as in Figure 3, a transition curve may beproduced showing the temperature transition from ductile (shear fracture) to brittle (cleavage fracture)behaviour of the material in question. The CVN impact values shown at the lower left of Figure 3 areindicative of low levels of notch toughness and brittle behaviour. This lower left brittle region of thetoughness-temperature curve is generally referred to as the "lower shelf". Alternatively, the CVN impactvalues shown at the upper right of Figure 3 are indicative of high levels of notch toughness and ductilebehaviour. This upper right ductile region of the toughness-temperature curve is generally referred to asthe "upper shelf".

When a notched bar is loaded, there is a normal stress across the base of the notch that tends toinitiate fracture. The "cohesive strength" of the material is the property that prevents it from cleaving.In cases of brittle fracture, the cohesive strength of a material is exceeded before significant deformationoccurs and the fracture surface appears flat and crystalline. In addition to the normal stress, the applied

3

load creates shear stresses that are oriented at about 45° to the normal stress. In cases of ductile orshear-type failure, the shear stress exceeds the shear strength of the material. For ductile failures,considerable deformation precedes final fracture and the broken surface is characterised by large shearlips that appear fibrous instead of crystalline in nature. In intermediate cases, the fracture occurs after amoderate amount of deformation and is part crystalline and part fibrous in appearance [Barsom & Rolfe(1999)].

The region between the two extremes of ductile and brittle behaviour is called the transition region.Various transition temperatures are established as an indication of the notch toughness of a structuralmaterial. The Ductile-to-Brittle Transition Temperature (DBTT) is defined as the temperature at whichthe material changes from ductile to brittle fracture, such that the behaviour is 50% ductile and 50%brittle [Barsom & Rolfe (1999)].

Figure 1. Charpy "full-size, Type A" V-Notch (CVN) impact test specimen according to the ASTME23 (1998) standard

L = 55 mmL/2

10 mm

10 mm

2mm

notch depth0.25 mm radius

45°90°

Permissible variations shall be as follows:

Notch length to edge, Adjacent sides shall be at, Cross-section dimensions, Length of specimen ( ), Centering of notch ( /2), Angle of notch, Radius of notch, Notch depth, Finish requirements,

LL

90 90 10

0. -2.5 mm

1

±±

+

±

° 2°° minutes

0.075 mm

1 mm°0.025 mm

0.025 mm2 m on notched surface

and opposite face; 2 m on other two surfaces

±

±

±±

µµ

4

(a) Liquid bath/cooler apparatus

(b) Placement of CVN specimen using centreing tongs

strik

er sw

ing

arc

Figure 2. Test setup

5

The ASTM E23 (1998) standard provides a methodology for determining the "percentage of shearfracture" on the fractured surface of a CVN test specimen as shown in Figure 4. The "shear area" ismeasured and simply expressed as a percentage of the total fractured area. Figure 5 shows a CVNtoughness-temperature plot for a cold-formed RHS tube, annotated with photographs of the fracturedsurfaces at various temperatures. From Figure 5 it can be seen that the fractured surface correspondingto temperatures of +20 °C and +45 °C can qualitatively be characterised as a ductile or shear-type failureexhibiting a fibrous failure surface. Conversely, the fractured surface corresponding to temperatures of-50 °C, -35 °C, -20 °C and 0 °C can qualitatively be characterised as a brittle failure exhibiting a flatcrystalline cleavage-type fracture surface. However, between the qualitative determination of a ductileversus a brittle failure surface, the quantitative evaluation of the "percent fibrous fracture" or"percentage of shear fracture" is imprecise at best and rather indeterminate in this case. Because of thesubjective nature of the evaluation of the fracture appearance, the ASTM E23 (1998) standard does notrecommend that this "percentage of shear fracture" determination be used in specifications.

Using a CVN toughness-temperature curve (as in Figure 3), the Ductile-to-Brittle TransitionTemperature (DBTT) can be taken to be the point on the curve, in the transition region, with the steepestslope. Alternatively, the Ductile-to-Brittle Transition Temperature (DBTT) has been defined as thetemperature corresponding to the energy value halfway between values obtained at 100% and 0%fibrous fracture [Barsom & Rolfe (1999)].

Cha

rpy

V-N

otch

toug

hnes

s (J)

Temperature (°C)

0Cleavage

propagation

Cleavageinitiation

Increasingshear

Full-shearpropagation

Full-shearinitiation

Increasingshear

upper shelf

lower shelf

NDTDBTT

(NDT) Nil-Ductility Temperature(DBTT) Ductile-to-Brittle Transition Temperature

Static loadingDynamic loading

Figure 3. Fracture toughness versus temperature behaviour of steel [adapted from Barsom (1991)]

6

Notch

A

B

Shear Area(dull)

Cleavage Area(shiny)

NOTE 1 - Measure average dimensions A and B to the nearest 0.5 mm.

Figure 4. Determination of percent shear fracture [adapted from ASTM E23 (1998)]

Figure 5. Experimental CVN toughness-temperature plot annotated with photographs of fracturedspecimens

RHS 102x102x12.7, cold-formed - Company B (Canada)[flat face, longitudinal, exterior notch]

-60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60

bsor

bed

ener

gy(J

)

0

100

150

200

Temperature (°C)

average line

Flat-A

Flat-Aexteriornotch

weldseam

-50 °C -35 °C0 °C

A

50

-20 °C

+20 °C +45 °C

7

The Nil-Ductility Temperature (NDT) is another transition temperature used to describe the notchtoughness of a structural material. The NDT, labelled in Figure 3, corresponds approximately to the firstrise in fracture toughness, from the lower shelf region of the toughness-temperature curve. Below theNDT, the material is considered to be brittle under the conditions of impact loading.

Figure 3 shows the CVN fracture toughness-temperature response of steel under both static anddynamic loading conditions. In addition to the change from ductile to brittle failure as the temperaturedecreases, Figure 3 also shows the influence of dynamic loads or the so-called dynamic shift. The CVNtoughness decreases as the load changes from static to dynamic. The brittle fracture lower shelf regionis essentially the same for static and dynamic loading conditions but the ductile failure upper shelftoughness is higher for impact loads [Bjorhovde et al. (2001)].

Of the three primary factors that influence the CVN fracture toughness of a given material (i.e.temperature, loading rate, and constraint), constraint is the most difficult to quantify. The primarydefinition of constraint deals with the plane strain to plane stress transition as affected by specimenthickness. Plane strain produces maximum constraint and occurs in very thick test specimens that havedeep cracks. In contrast, plane stress produces minimum restraint and occurs in thin test specimens.

Figure 6 is a schematic representation of the state of stress at the tip of a through-thickness crack in asharply notched specimen loaded in tension. For a uniform state of stress, where the three principalstresses σX, σY, and σZ are equal, there are no shear stresses. This would result in complete constraintagainst plastic flow. In the case of most notched specimens, the principal stresses are not equal, with σY

> σX or σZ. Thus, shear stresses will develop along a given plane leading to some plastic yielding. Tosatisfy compatibility conditions, the plastic "cylinder" (idealised plastic-zone region) in Figure 6 thatdevelops ahead of the crack tip must increase in diameter with an increase in stress in the Y-directiondue to the applied load. However, a corresponding through-thickness lateral contraction must occur inthe Z-direction. This lateral contraction is constrained by the reaction-stress system of the elasticallystressed material surrounding the plastic "cylinder". Furthermore, the material behind the notch isunstressed because of the free surface of the notch and adds to the lateral constraint ahead of the notch.

σ

σY

σX

σZ

σ

thicknessY strain

Z contraction

Figure 6. Constraint conditions for through-thickness cracks [from Barsom & Rolfe (1999)]

8

These constraints produce a triaxial state of stress that reduces the apparent ductility of the material bydecreasing the shear stresses. Because yielding is restricted, the constraint ahead of the crack tip isincreased and thus the relative fracture toughness is reduced [Barsom & Rolfe (1999)].

An increase in either the "width" (analogous to the "thickness" dimension in Fig. 6) or depth of aCharpy V-Notch (CVN) specimen will increase the volume of material subject to distortion, and by thisfactor tends to increase the energy absorption when breaking the specimen. However, an increase inspecimen size, particularly in width, also tends to increase the degree of constraint. This increase inconstraint can tend to induce brittle fracture and thus decrease the amount of energy absorbed by thespecimen. Where a standard-size specimen is on the verge of brittle fracture, this is particularly true,and a double width specimen may actually require less energy for rupture than one of standard width.Thus, a general correlation between the energy values obtained with specimens of different size or shapeis not feasible [ASTM A370 (1997)].

The standard "full-sized, Type-A" CVN test specimen according to the ASTM E23 (1998) standard isshown in Figure 1. However, when CVN specimens other than the standard size are necessary orspecified, the ASTM E23 (1998) standard recommends so-called Subsize Type-A specimens be selectedfrom Figure 7. As mentioned earlier in the discussion of induced constraint conditions, generalcorrelation between energy values obtained with specimens of different size or shape is not feasible.However, "...limited correlations may be established for specification purposes on the basis of specialstudies of particular materials and particular specimens" as noted in the ASTM E23 (1998) standard.For example, the ASTM A673 (1995) specification for structural steel contains a table of equivalentabsorbed energies for various subsize CVN specimens.

Figure 7. Charpy "Subsize Type-A" impact test specimens [from ASTM E23 (1998) standard]

45° ( 1°)±

0.25 mm notch tip radius

55 mm length(+0, -2.5 mm)

width

notch depthdepth

(i) 10 mm

(ii) 5 mm

(iii) 3 mm

2 mm notch depth

1 mm notch depth

0.610 mm notch depth

(a)2.5 mm

(b)5 mm

(c)7.5 mm

(d)10 mm

(e)20 mm

standard size

9

1.4 Related researchThe experimental research programme presented in this report involves sampling mainly standard sizeCVN test specimens from various orientations and locations within the cross-section of an RHS tube.Previous research by Dagg et al. (1989) involved determining the relationship between the transitiontemperature of material sampled from the flat face and that of material sampled from the corners of cold-formed RHS tubes. In their research, the CVN test specimens were artificially aged at 170 °C for 30minutes. Figure 8 shows the average (average of three duplicate CVN tests) toughness-temperatureresults of two different RHS tube sizes; namely 203x203x9.5 mm and 76x76x6.3 mm. The wallthicknesses of the RHS tubes, being less than 10 mm, precluded the use of a standard size 10 mm x 10mm CVN test specimen. Figure 8(b) shows a schematic of the subsize 5 mm x 10 mm CVN testspecimen, and the sampling locations [Figure 8(a)] within the RHS tube cross-section, used in theirstudy. As evidenced in Figures 8(c) and (d), Dagg et al. (1989) found little difference between thetoughness-temperature results of CVN test specimens sampled from the flat face versus the cornerregion for both RHS tubes.

Figure 8. CVN testing of flat face versus corner region of RHS tubes [from Dagg et al. (1989)]

(a) CVN specimen locations (b) 10 mm x 5 mm subsize CVN specimen

(c) RHS 203 x 203 x 9.5 CVN results (d) RHS 76 x 76 x 6.3 CVN results

-70 -50 -30 -10 10 30 50

80

70

60

50

40

30

20

10

0

Test temperature (°C)

Abs

orbe

d en

ergy

(Jou

les)

FlatsCorners

-70 -50 -30 -10 10 30 50

80

70

60

50

40

30

20

10

0

Test temperature (°C)

Abs

orbe

d en

ergy

(Jou

les)

FlatsCorners

5 mm

5 mm

10 mm

10 mm

weldseam

55 mm

10 mm

5 mm

10

Of particular interest, Dagg et al. (1989) used a through-thickness notch orientation. Thus the notchtip, the origin of the cleavage/fracture plane, may have characterised the average through-thicknessmaterial properties of the RHS tube. Thus, the CVN test specimens sampled from the corner region ofthe RHS tube may have, to some extent, "averaged-out" the cold-working material effects induced bythe outside radius' tensile residual stresses, the inside radius' compressive residual stresses, and theneutral axis' lack of residual stresses. Thus, the through-thickness notch orientation may not haveeffectively exploited the maximum potential differences in notch toughness between the flat face versusthe corner region of the RHS tube.

Soininen (1996) has performed an extensive series of CVN tests on cold formed RHS. His CVN testspecimens were sampled from the following materials and delivery states:

• base coil material with CVN test specimens taken longitudinal and transverse to the rolling directionof the coil

• flat side of the RHS with CVN test specimens taken longitudinal and transverse to the rollingdirection of the coil

• flat side of the RHS after artificial ageing at 250 °C/30 min

• corner area of the RHS in the delivery condition and after artificial ageing at 250 °C/30 min

Soininen (1996) found that transverse specimens had, on average, 19 °C higher transition temperaturesboth in the base (coil) material and in the flat face region of the cold formed RHS material, compared tothe longitudinal specimens. The increase in the transition temperature from the base (coil) material tothe cold formed RHS material (flat face location, longitudinal CVN orientation) was on average 15 °C.The increase in the transition temperature from the base (coil) material to corner region of the coldformed RHS material was on average 23 °C. Similar to the overall findings of Dagg et al. (1989),Soininen (1996) reported a surprisingly small difference in the average transition temperature (8 °C)between the flat face and corner region of the RHS tubes tested. Both Soininen (1996) and Dagg et al.(1989) used through-thickness notch orientations. One of the overall conclusions of Soininen (1996)was that in order to fulfil a certain CVN toughness requirement in the finished cold formed RHS, at acertain temperature, the base (coil) material had to fulfil the same notch toughness at a temperaturewhich was at least 30° lower.

The experimental research programme presented in this report contains CVN notch tip orientationsthat lie along either the outer radius or the inner radius of the corner region of the RHS tubes. Thesenotch orientations may serve to better exploit any differences between the flat face and corner regions ofthe RHS tube.

The experimental research programme presented in this report also contains a comparison of CVNtest results between a cold-formed and a cold-formed/stress-relieved tube. In terms of comparing thetoughness properties of RHS that have undergone significant heat treatment, Figure 9 shows acomparison of CVN test results between RHS whose walls were locally thickened by a recent processdeveloped in Japan. In an effort to avoid diaphragm-reinforced connections, the Japanese havedeveloped a method for locally thickening the tube walls, in the connection region, through theapplication of induction heating and simultaneous axial compression force. As evidenced in Figure 9,this process of locally thickening the RHS walls has the added benefit of improving the CVN toughnesscurves.

11

2 Experimental Test Programme

2.1 Material propertiesHollow sections produced to either North American or European standards were used in theexperimental test programme. Tubes were obtained from six different international manufacturers;herein designated as Companies A & B (Canada), Company C (Germany), Company D (Brazil),Company E (France) and Company F (Finland). Table 1 contains complete details regarding thegeometrical, mechanical, and chemical properties of the tubes.

2.2 Thermal conditioning of CVN specimensA liquid bath/cooler arrangement, shown in Figure 2(a), was used to hold the CVN specimens to thedesired test temperature. The temperature of the liquid bath was measured using a thermocouplethermometer (Model No. 600-1040, with a Type J thermocouple probe, manufactured by the BarnantCompany). The thermocouple has a temperature range of -200 °C to +1000 °C. All specimens werethermally conditioned for at least five minutes before being tested. To ensure complete and uniformimmersion of the CVN test specimens in the liquid coolant, a perforated stainless steel plate [as can beseen in Fig. 2(a)] was used to elevate the CVN specimens 25 mm above the bottom of the cooler whilethe tops of the specimens were submerged by an additional 25 mm of the liquid coolant.

Methanol was used as a liquid coolant with varying amounts of "dry-ice" (frozen carbon dioxide).The dry-ice, which has an ambient temperature of -87.5 °C, was proportioned by trial and error in themethanol bath to achieve the desired conditioning temperature for the CVN specimens. Conditioningtemperatures as low as -75 °C were achieved using this methodology.

300 300

250 250

200 200

150 150

100 100

50 50

0 0-120 -120-100 -100-80 -80-60 -60-40 -40-20 -200 020 20

Thickened base ( ) Thickened base ( )

Orig

inal

bas

e ( )

Orig

inal

bas

e ( )

Thickened corner ( ) Thickened corner ( )

Orig

inal

cor

ner (

)

Orig

inal

cor

ner (

)

Abs

orbe

d en

ergy

(J)

Abs

orbe

d en

ergy

(J)

Temperature (°C) Temperature (°C)

(a) RHS 300x300x12 original size (b) RHS 300x300x16 original size

Figure 9. CVN test data for locally thickened RHS [from Dai-Ichi High Frequency Co. (2002)]

12

Tabl

e 1.

Mat

eria

l pro

perti

es o

f Hol

low

Stru

ctur

al S

ectio

ns

Man

ufac

ture

rCo

mpa

ny B

(Can

ada)

Com

pany

C(G

erm

any)

Com

pany

E(F

ranc

e)C

ompa

ny F

(Fin

land

)N

omin

al si

zeR

HS

305x

305x

12.7

(m

m)

RH

S25

4x25

4x15

.9

(mm

)

RHS

102x

102x

12.7

(m

m)

RH

S10

0x10

0x12

.5

(mm

)

CH

S 32

4x8.

4"o

rigin

al tu

be"

(mm

)

RH

S 25

5x25

5x8.

4"f

inal

tube

"(m

m)

RH

S35

0x35

0x12

.5(m

m)

RH

S25

0x25

0x12

.5(m

m)

Man

ufac

turin

g pr

oces

s and

st

eel g

rade

cold

form

ed &

stre

ss-r

elie

ved

A50

0BA

STM

A50

0-01

(200

1)

cold

-for

med

A50

0CA

STM

A50

0-01

(200

1)

cold

-for

med

A50

0CA

STM

A50

0-01

(200

1)

hot-r

olle

d

S355

J2H

EN10

210-

1 (1

994)

cold

-for

med

&str

ess-

relie

ved

S355

J2H

conf

orm

ing

toEN

1021

0-1

(199

4)

cold

-for

med

S355

J2H

EN10

219

(199

7)

Clas

s HC

SA (1

998)

Cla

ss C

CSA

(199

8)C

lass

CCS

A (1

998)

Yie

ld st

reng

th, F

y44

9 M

Pa43

0 M

Pa49

3 M

Pa37

7 M

Pa36

9 M

Pa-

470

MPa

471

MPa

Ulti

mat

e St

reng

th, F

u56

6 M

Pa51

1 M

Pa55

2 M

Pa53

4 M

Pa48

5 M

Pa-

547

MPa

545

MPa

Elon

gatio

n at

failu

rea

36%

35%

25%

30%

37%

-24

%27

%

Car

bon,

C0.

180%

0.21

0%0.

180%

0.16

0%0.

157%

0.07

0%Si

licon

, Si

0.23

0%0.

040%

0.05

0%0.

230%

0.19

0%0.

210%

Man

gane

se, M

n0.

850%

0.79

0%0.

810%

1.35

0%1.

345%

1.43

0%Ph

ospo

rous

, P0.

008%

0.00

7%0.

011%

0.01

5%0.

014%

0.01

2%Su

lphu

r, S

0.00

5%0.

005%

0.00

6%0.

002%

0.00

8%0.

005%

Alu

min

um, A

l-

0.03

7%0.

041%

0.03

8%0.

036%

0.03

9%Va

nadi

um, V

-0

-0.

040%

00.

007%

Cop

per,

Cu-

0.16

0%0.

063%

-0.

020%

0.01

8%N

icke

l, N

i-

0.05

0%0.

020%

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020%

0.03

5%C

hrom

ium

, Cr

-0.

060%

--

0.03

0%0.

027%

Mol

ybde

num

, Mo

--

--

0.01

0%0.

004%

Nitr

ogen

, N-

--

-0.

002%

0.00

4%N

iobi

um, N

b-

--

-0

0.02

5%Ti

n, S

n-

--

-0

-Ti

tani

um, T

i-

--

-0.

017%

0.01

6%

a For A

STM

and

CSA

spec

ifica

tions

, gau

ge le

ngth

typi

cally

is 2

inch

es.

For E

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ecifi

catio

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auge

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5.6

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st co

upon

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0.01

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0.02

0% - - -

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0.96

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013%

(a)

Gen

eral

tube

des

crip

tion

(b)

Mec

hani

cal p

rope

rtie

s (re

porte

d by

man

ufac

ture

r)

(c)

Che

mic

al c

ompo

sitio

n by

wei

ght (

repo

rted

by m

anuf

actu

rer)

Com

pany

A(C

anad

a)C

ompa

ny D

(Bra

zil)

cold

-sha

ped

into

RH

Sfr

om h

ot-ro

lled

CHS

A53

BA

STM

A53

/A53

M-0

1(2

001)

13

2.3 Impact testing of CVN specimensA Tinius-Olsen Change-O-Matic impact machine (Figure 2) with a 260 ft⋅lb (352 N⋅m or Joule) directreading scale was used to perform all CVN impact tests. The CVN specimens were taken from theliquid bath/cooler apparatus [Figure 2(a)] and placed into the machine testing bed. Figure 2(b) shows aCVN specimen being placed between the inner walls of the testing bed support anvils using self-centreing tongs. The self-centreing tongs comply with the ASTM E23 (1998) standard.

In accordance with the ASTM E23 (1998) standard, each CVN specimen was tested within a stricttime interval. Inside of a maximum-allowed five second time interval, the CVN specimen was removedfrom the liquid bath and placed in the testing bed using the self-centreing tongs; the striker pendulumwas raised to the latched position and released without vibration to impact the CVN specimen.

2.4 Compliance of testing machineThe ASTM E23 (1998) standard specifies annual verification of impact testing machines to ensure thequality and consistency of data collected therein. The National Institute of Standards and Technology(NIST) conducts a Charpy machine qualification programme (Vigliotti et al. 2000), originally developedby the U.S. army, that is referenced in the ASTM E23 (1998) standard. Under this programmeverification specimens, supplied by NIST and stamped with individual specimen identification numbers,are used to certify a Charpy impact testing machine.

A set of four Standard Reference Materials (SRM) 2092-Low Energy Charpy V-Notch, supplied byNIST, were used to check the compliance of the Tinius Olsen machine (Fig. 2) used in this experimentaltest programme. The four reference test specimens were tested in accordance with the ASTM E23(1998) standard. The test results, the broken CVN test specimens, and a standardised verificationquestionnaire were mailed to the Charpy Program Coordinator at The National Institute of Standardsand Technology (NIST) for analysis. The NIST evaluation confirmed that the numerical results of thefour Standard Reference Materials (SRM) 2092-Low Energy Charpy V-Notch specimens fell within theacceptable range of energy values.

2.5 Scope of experimental test programmeFigure 10 shows the sampling locations and orientations of the CVN test specimens. For each tube typeand manufacturer, Charpy V-Notch (CVN) test coupons were taken from various locations around thecross-section. Numerous specimens were prepared from every location so that the complete toughness-temperature transition curve could be generated (between approximately -75 °C and +50 °C) for various:

• cross-section locations (flats, corner, and weld seam)• specimen orientations (longitudinal versus transverse)• face exposures (notch on interior face of tube, versus exterior face).

14

3 Discussion and analysis of results

Figure 11 shows the toughness-temperature transition curves for the eight tube types sampled with CVNtest specimens. Because of the inherent scatter of CVN test results, either two or three (usually three)replicate specimens were tested at each target temperature and the average result was used to plot thetoughness-temperature curve. In total, 557 CVN specimens have been machined and impact tested.

3.1 CVN toughness requirementsIn Europe, the most common grade of cold-formed structural tubing available now is S355J2H to EN10219-1 (1997). This guarantees a minimum notch toughness of 27 Joules at -20 °C, which is likelyadequate for most dynamic loading situations. The toughness-temperature curves, representing theresults of this experimental programme, are annotated with this 27 Joule requirement as a generalbenchmark for comparison.

In North America however, the prevailing ASTM A500 (2001) specification has no notch toughnessclassifications for various grades. Instead, within the Scope it states “...Note 1 - Products manufacturedto this specification may not be suitable for those applications such as dynamically-loaded elements inwelded structures, etc., where low-temperature notch-toughness properties may be important.”

The Canadian CSA G40.21-98 (1998) standard specifies minimum CVN requirements, for the basemetal, according to four standard temperature categories as shown in Figure 12. However, structuraltubing with a notch toughness category is not commonly produced in North America, yet this has notinhibited its ubiquitous use for all manner of applications.

The International Institute of Welding (IIW 2003) has recently prepared a report to address the risk offracture in seismically-affected moment connections. Table 2 shows two qualitative Risk AssessmentProcedures (RAPs) based on the Charpy V-Notch toughness of the weld metal, heat affected zone andparent material. Table 2(a) represents a simple and generally conservative method based primarily onpractical experience from the Kobe and Northridge earthquakes. Table 2(b) is based on a series ofanalytical studies using a combination of finite element and fracture mechanics methods by Burdekin &Kuntiyawichai (2001).

interiornotch

exteriornotch

weldseam

weld seam

exteriornotch

longitudinaltransverse

Fig. 10. Sampling locations and orientations of CVN test specimens

15

(i) Seam weld (ii) Flat face

Longitudinal, exterior faceTransverse, exterior face

Flat face (average trend)

(iii) Corner

Longitudinal, exterior faceLongitudinal, exterior faceLongitudinal, interior face

Corner (average trend)

(a) RHS 305x305x12.7, cold-formed, stress-relieved. Company A (Canada)

-60 -45 -30 -15 0 15 30 45 60

Abs

orbe

d en

ergy

(J)

0

50

100

150

200

250

300

350

400

Temperature (°C)

weld (transverse)

corner (interior)

(b) RHS 254x254x15.9, cold-formed. Company A (Canada)

-60 -45 -30 -15 0 15 30 45 60

Abs

orbe

d en

ergy

(J)

0

50

100

150

200

250

300

350

400

Temperature (°C)

weld (transverse)

corner (interior)

(c) RHS 102x102x12.7, cold-formed. Company B (Canada)

-60 -45 -30 -15 0 15 30 45 60

Abs

orbe

d en

ergy

(J)

0

50

100

150

200

250

300

350

400

Temperature (°C)

weld (transverse)

weld (longitudinal)

(d) RHS 100x100x12.5, hot-rolled. Company C (Germany)

-60 -45 -30 -15 0 15 30 45 60

Abs

orbe

d en

ergy

(J)

0

50

100

150

200

250

300

350

400

Temperature (°C)

27 J 27 Joules

27 Joules 27 Joules

Transverse, exterior faceTransverse, interior face

Longitudinal, exterior faceSeam weld (average trend)

Figure 11. Plots of Charpy toughness-temperature results for all tubes tested

weld (longitudinal)

flat face(longitudinal)

corner (exterior)

weld (longitudinal) flat face

(longitudinal)

corner (exterior)


corner-D(exterior)

flat face(transverse)

corner-B(exterior)


corner (exterior)


corner (interior)

16

(g) RHS 350x350x12.5, cold-formed, stress-relieved. Company E (France)

-75 -60 -45 -30 -15 0 15 30

Abs

orbe

d en

ergy

(J)

0

50

100

150

200

250

300

350

400

Temperature (°C)

27 Joules

(e) Original tube: CHS 324x8.4, hot-rolled. Company D (Brazil)

(f) Final tube: RHS 255x255x8.4, cold-shaped into RHS from hot-rolled CHS. Company D (Brazil)

-75 -60 -45 -30 -15 0 15 30

Abs

orbe

d en

ergy

(J)

0

10

20

30

40

50

60

70

80

90

100

Temperature (°C)

"Original" CHS tube(longitudinal)

"Final" RHSflat face(longitudinal)

CHS (average trend)Longitudinal, exterior face (CHS)

-75 -60 -45 -30 -15 0 15 30

Abs

orbe

d en

ergy

(J)

0

10

20

30

40

50

60

70

80

90

100

Temperature (°C)


corner (exterior)

corner (interior)


corn

er (i

nter

ior)

corn

er(e

xterio

r)

weld (transverse)

(i) Seam weld (ii) Flat face (iii) Corner

Longitudinal, exterior faceSeam weld (average trend)

Longitudinal, interior faceLongitudial, exterior face

Transverse, exterior face

Corner (average trend)

(h) RHS 250x250x12.5, cold-formed. Company F (Finland)

-75 -60 -45 -30 -15 0 15 30

Abs

orbe

d en

ergy

(J)

0

50

100

150

200

250

300

350

400

Temperature (°C)

27 Joules

flat face (longitudinal)

corn

er

(inter

ior)

corner

(exterior)


weld (longitudinal)

weld (transverse)

352 Joule testcapacity exceeded

Fig. 11 (...con'd). Plots of Charpy toughness-temperature results for all tubes tested


weld (longitudinal)


Longitudinal, exterior faceTransverse, exterior face

Flat face (average trend)

5 mm x 10 mmSubsize specimens used

5 mm x 10 mmSubsize specimens used

17

-45 -30 -20 0

Spec

ified

min

imum

CV

Nen

ergy

(J)

0

5

10

15

20

25

30

35

40

Standard test temperature (°C)

Cate

gory

4

Cate

gory

3

Cate

gory

2

Cate

gory

1

27 J ( for 350-550 MPa steels*)

20 J ( for 260-300 MPa steels*)

34 J ( for 700 MPa steels*)

*minimum specified yield stress of steel

Figure 12. Canadian CVN toughness requirements [CSA G40.21-98 (1998)]

Table 2. Risk of fracture in seismically-affectedmoment connections [from IIW (2003)]

Risk of brittle fracture100 ≤ Cv Very low risk

47 ≤ Cv < 100 Low risk27 ≤ Cv < 47 Medium risk10 ≤ Cv < 27 High risk

Cv < 10 Very high risk

Toughness level40°C < (Tmin - T27) High toughness20°C ≤ (Tmin - T27) ≤ 40°C Medium toughness0°C < (Tmin - T27) < 20°C Low toughness

notes:Tmin is the minimum service temperature at which an

earthquake is considered likely to occurCv is the Charpy energy at the minimum service temp., Tmin

T27 is the temp. for a minimum 27 J Charpy energy absorption

(a) Level I Assessment

(b) Level II Assessment

Charpy energy (J) @ Tmin

Temp. difference (°C)

18

The experimental research programme presented reports on the influence of sampling location andorientation on the CVN toughness for HSS. The IIW (2003) report prudently notes that “Parent materialCharpy properties may be obtained from supplier's test certificates but the possibility of carrying outcheck tests, particularly in the transverse direction should be considered.”

3.2 Cold-formed versus cold-formed/stress-relieved tubes“Class H” is a Canadian Standards (1998) category of electric resistance welded (ERW) tube, cold-formed to final shape, then stress-relieved by heating to 450 °C or higher, followed by cooling in air, toproduce stress-strain behaviour which is comparable to hot-rolled sections. In particular, this heattreatment provides partial relief of residual stresses and justifies the use of a higher column curve for useas a compression member. It is a common belief that this Class H heat treatment provides superior notchtoughness properties, similar to hot-rolled sections, as well.

Both a cold-formed and a cold-formed/stress-relieved (Class H) tube were tested in order todetermine the relative benefit of stress-relieving with respect to notch toughness. Both tubes wereproduced by Company A (Canada) and possess similar mechanical and chemical properties asdocumented in Table 1. However, it is to be noted that the two tubes were produced in separate batches.

Figures 11(a) and (b) show the toughness-temperature results of the cold-formed/stress-relieved andcold-formed tubes respectively. In particular, it was anticipated that any differences between the cold-formed and cold-formed/stress-relieved tubes would be most pronounced in the corner location wherethe residual stresses would be highest. CVN specimens were taken from the corners of the tubes withthe notches facing either the interior (predominantly compressive residual stresses) or the exterior(predominantly tensile residual stresses). Figures 11(a) and (b) show little difference between the CVNtoughness of cold-formed/stress-relieved, and cold-formed tubes, even in the corner location where theeffects of stress-relieving would be expected to be most pronounced and beneficial.

This particular RHS in Fig. 11(a) was heated to 496 °C (± 14 °C) for at least 30 minutes then air-cooled. However, to normalise the steel it must be heated to a temperature above the uppertransformation temperature (approximately 830 °C to 900 °C) and cooled in air. Thus, the modeststress-relieving process will not produce a metallurgical change and this is evident in comparing Figs.11(a) and 11(b), as there is little improvement in notch toughness by stress-relieving using this heattreatment.

3.3 Cold-formed versus hot-rolled tubesIn the previous section, it was observed that the CVN toughness benefit of a cold-formed/stress-relievedtube over a standard cold-formed tube was insignificant. On the other hand, Fig. 11(d) shows whatexcellent toughness properties are achieved at all locations around the cross-section by the hot-rollingprocess. (This RHS was grade S355J2H to EN 10210 (1994)).

Fig. 11 also displays some other interesting relationships between the cold-forming and hot-rolling(or hot-finishing) processes. In Brazil, a company produces CHS by the hot-rolling process then shapesthese into RHS by cold-forming. Fig. 11(e) shows that this RHS manufacturing method causes onlyminor degradation of the notch toughness properties in the longitudinal direction, and little differencebetween the longitudinal and transverse coupon directions (Fig. 11(f)). The largest decrease in CVNlevels from the hot-rolled CHS to the shaped RHS occurred in the corners, where cold-working was amaximum. One should note that the lower number of Joules reported in Figs. 11(e) and 11(f) is likelydue to sub-sized 5 x 10 x 55mm CVN coupons being used, compared to the full-size 10 x 10 x 55mmCVN coupons, and as such the 27 Joule benchmark does not apply.

19

3.4 Toughness results versus CVN sampling location and orientationStandard CVN specimens are usually taken from the flat face of the RHS and are oriented parallel to therolling direction of the source steel (i.e. longitudinal to the RHS axis). This standard longitudinal flatface CVN test specimen is specified by the Canadian CSA G40.21-98 (1998) standard, for example, aswell as other international standards and specifications.

The so-called CVN toughness of a RHS is highly dependent on the sampling location and orientationof the CVN test specimens. In general, the flat face RHS location and longitudinal rolling orientationproduce the highest toughness values. Conversely, the corner and weld seam regions of the RHSgenerally produce lower CVN toughness values than the flat face. In addition, transversely-orientedCVN specimens tend to produce lower CVN toughness values than their longitudinally-orientedcounterparts. These general trends can be seen in Figure 11 for all of the tubes tested.

Of all the combinations of sampling locations and orientations, a CVN specimen sampled at thelocation of a weld seam, and oriented transversely to the weld seam, generally produced the lowesttoughness values for the cold-formed RHS. These low toughness values for CVN specimens orientedtransversely at the location of a weld seam are in stark contrast to the more favourable toughness valuesobtained from CVN specimens sampled longitudinally at the flat face location.

3.5 European versus North American CVN toughness requirementsIt is important to note the worth of requiring a certain CVN value to be demonstrated by the product.The European cold-formed RHS in Figures 11 (g) and (h) required 27 Joules at -20 oC. Although this isfar exceeded at the specified testing location, it is even achieved at any location and direction, instillingconfidence in the product. For the ASTM A500 RHS, which admittedly had no notch toughnessrequirement, this “benchmark” of 27 Joules at -20 oC is provided at the specified testing location in twoof the three RHS (Figs. 11(a) and 11(b)), but in no cases is it met at the worst (critical) location.

4 Final Conclusions

• For dynamic loading situations where notch toughness is a design criterion, cold-formed RHS maybe able to satisfy a required energy absorption capacity at the Lowest Anticipated Servicetemperature (LAST), providing the CVN coupon is taken longitudinally from the flat face region andaway from the seam weld, according to typical specifications. High quality cold-formed hollowsections have also been shown to be able to provide excellent notch toughness properties, at varioussection locations. For the hot-formed sections tested the toughness at any location or orientation inthe cross-section was good.

• For cold-formed RHS, there is little improvement in notch toughness achieved by stress-relievingthe section by heat treatment according to CSA (1998) “Class H” requirements. Thus, cold-formed/stress-relieved RHS are not advocated over cold-formed RHS, for situations where dynamic loadingis a design criterion.

• RHS manufacturing specifications typically require a CVN coupon to be taken longitudinally fromthe flat face region (and away from the seam weld if the RHS is cold-formed), if notch toughnessproperties need to be demonstrated because of a purchasing requirement. This leads to the mostoptimistic notch toughness result for the cross-section and serious consideration must be given tospecifying alternate coupon locations, so that the RHS is “fit for purpose”. The flat face transverse

20

CVN coupon generally results in a lower notch toughness than the flat face longitudinal CVNcoupon, for all RHS production methods.

5 Acknowledgements

Financial support for this project was provided by the Comité International pour le Développement etl’Étude de la Construction Tubulaire (CIDECT), the Steel Structures Education Foundation (Canada)and the Natural Sciences and Engineering Research Council of Canada (NSERC).

All experimental work reported was performed at the University of Toronto. Special recognitiongoes to Kevin Yong-Ping and Ora Zobin who impact tested batches of CVN specimens as part of theirundergraduate theses.

6 References

ASTM A53/A53M-01 (2001). “Standard specification for pipe, steel, black and hot-dipped, zinc-coated,welded and seamless,” ASTM International, West Conshohocken, Pennsylvania, USA.

ASTM A370-97a (1997). “Standard test methods and definitions for mechanical testing of steelproducts,” ASTM International, West Conshohocken, Pennsylvania, USA.

ASTM A500-01 (2001). “Standard specification for cold-formed welded and seamless carbon steelstructural tubing in rounds and shapes,” ASTM International, West Conshohocken, Pennsylvania,USA.

ASTM A673-95 (1995). “Specification for sampling procedure for impact testing of structural steel,”ASTM International, West Conshohocken, Pennsylvania, USA.

ASTM E23-98 (1998). “Standard test methods for notched bar impact testing of metallic materials,”ASTM International, West Conshohocken, Pennsylvania, USA.

AWS (2002). “Structural welding code – steel,” American Welding Society, 18th Edition, Miami,Florida, USA.

Barsom, J.M. (1991). “Properties of bridge steels,” Highway structures design handbook, Chapter 3,Vol. I, AISC Marketing Inc., Chicago, Illinois, USA.

Barsom, J.M., & Rolfe, S.T. (1999). Fracture and fatigue control in structures, American Society ofCivil Engineers, Philadelphia, Pennsylvania, USA.

Bjorhovde, R., Engstrom, M.F., Griffis, L.G., Kloiber, L.A., & Malley, J.O. (2001). Structural steelselection considerations, American Society of Civil Engineers, Reston, Virginia, USA.

Burdekin, F.M., & Kuntiyawichai, K. (2001). “Elastic plastic FE analyses of sub models of connectionsin steel framed moment resisting buildings under earthquake loading.” IIW Doc. XV-1474-01, IIWAnnual Assembly, Ljubljana, Slovenia.

CAN/CSA-G40.20-98 (1998). “General requirements for rolled or welded structural quality steel,”Canadian Standards Association, Toronto, Canada.

21

CAN/CSA-G40.21-98 (1998). “Structural quality steels,” Canadian Standards Association, Toronto,Canada.

Dagg, H.M., Davis, K., & Hicks, J.W. (1989). “Charpy impact tests on cold formed RHS manufacturedfrom continuous cast fully killed steel,” Proceedings of the Pacific Structural Steel Conference,Australian Institute of Steel Construction, Queensland, Australia.

Dai-Ichi High Frequency Co., Ltd., Nogata, Japan (2002). Private Communication.

EN10210-1 (1994). “Hot finished structural hollow sections of non-alloy and fine grain steels. Part 1-Technical delivery requirements,” European Committee for Standardisation, British StandardsInstitution, London, England.

EN10219 (1997). “Cold formed welded structural hollow sections of non-alloy and fine grain steels.Part 1: Technical delivery requirements, and Part 2: Tolerances, dimensions and sectionalproperties,” European Committee for Standardisation, British Standards Institution, London,England.

International Institute of Welding, JWG of Commissions X and XV-G (2003). “IIW recommendationsfor assessment of risk of fracture in seismically affected moment connections,” IIW Doc. XV-1102-03, IIW Annual Assembly, Bucharest, Romania.

Soininen, R. (1996). Fracture behaviour and assessment of design requirements against fracture inwelded steel structures made of cold formed hollow sections, Tieteellisiä Julkaisuja Research Papers52, Lappeenranta University of Technology, Lappeenranta, Finland.

Vigliotti, D.P., Siewart, T.A., & McCowan, C.N. (2000). “Installing, maintaining, and verifying yourcharpy impact machine,” Special Publication 960-4, National Institute of Standards and Technology,Washington, DC, USA.

22

Table A1. CVN test results for cold-formed/stress-relieved RHS 305x305x12.7 (Company A - Canada)

ID Temp. Energy ID Temp. Energy ID Temp. Energy ID Temp. Energy ID Temp. Energy ID Temp. Energy (°C) (J) (°C) (J) (°C) (J) (°C) (J) (°C) (J) (°C) (J)

CT11 -48.9 8.1 CL9 -48.1 19.0 A11 -49.7 4.1 B13 -49.5 12.2 D10 -48.1 5.4CT12 -48.9 16.3 CL10 -48.1 25.8 A12 -49.7 12.2 B14 -49.3 6.8 D11 -47.9 5.4CT13 -48.2 16.3 A13 -49.7 12.2 D12 -47.9 2.7CT17 -48.7 10.8 D15 -48.8 4.7CT18 -48.5 8.1avg. -48.6 11.9 avg. -48.1 22.4 avg. -49.7 9.5 avg. -49.4 9.5 avg. -48.2 4.6CT5 -34.3 12.2 CL7 -33.9 23.1 A4 -35.1 8.1 B11 -34.5 17.6 D3 -33.9 8.1CT9 -34.3 16.3 CL8 -33.9 40.7 A10 -35.1 19.0 B10 -34.3 16.3 D6 -33.9 8.1

CT10 -34.3 13.6 A3 -35.0 14.9 D9 -33.9 8.1avg. -34.3 14.0 avg. -33.9 31.9 avg. -35.1 14.0 avg. -34.4 17.0 avg. -33.9 8.1CT7 -17.4 19.0 CL5 -17.3 149.3 A9 -18.7 46.1 B7 -18.6 38.0 D7 -18.6 13.6CT8 -17.3 23.1 CL6 -17.2 135.7 A8 -18.6 40.7 B9 -18.4 111.3a D8 -18.3 19.0

B8 -18.3 59.7B3 -17.2 54.3

avg. -17.4 21.0 avg. -17.3 142.5 avg. -18.7 43.4 avg. -18.0 50.7 avg. -18.5 16.3CT4 1.0 36.6 CL3 1.0 157.4 A5 1.0 164.9 B4 1.0 138.4 D4 1.0 32.6CT6 1.0 31.2 CL4 1.0 184.6 A6 1.0 177.8 B5 1.0 122.1 D5 1.0 38.0

A7 1.0 210.3a B6 1.0 130.3avg. 1.0 33.9 avg. 1.0 171.0 avg. 1.0 171.3 avg. 1.0 130.3 avg. 1.0 35.3CT1 17.0 48.9 CL1 17.0 175.1 A1 17.0 203.6 B1 17.0 147.9 D1 17.0 55.6CT2 17.0 40.7 CL2 17.0 177.8 A2 17.0 196.8 B2 17.0 154.7 D2 17.0 52.9CT3 17.0 40.0avg. 17.0 43.2 avg. 17.0 176.4 avg. 17.0 200.2 avg. 17.0 151.3 avg. 17.0 54.3

CT16 45.5 67.9 A15 47.0 199.5 B12 46.1 162.8 D14 46.5 157.4CT15 46.0 61.1 A14 47.1 203.6 B15 46.1 168.3 D13 46.6 165.6CT14 46.2 81.4avg. 45.9 70.1 avg. 47.1 201.5 avg. 46.1 165.6 avg. 46.6 161.5

note: aextraneous data point

Transverse

17 °C

46 °C

Exterior face

-34

°C1

°C-4

9 °C

-18

°C

(a) Steel grade: Class H (stress-relieved) [CAN/CSA-G40.20-98], Manufactured by: Company A (Canada), RHS designation: RHS 305x305x12.7

Specimen taken from: Seam weld Flat face of RHSLocation ALocation C

Corner of RHSLocation B Location D

Exterior face Interior faceLongitudinal Transverse Longitudinal Longitudinal Longitudinal

Exterior faceExterior faceExterior face

D DA AB B

C C Cweldseam

interiornotch

exteriornotch

exteriornotchtransverse longitudinalTube (a)

RHS 305x305x12.7Cold-formed/stress-relieved

Company A (Canada)

23

Table A2. CVN test results for cold-formed RHS 254x254x15.9 (Company A - Canada)


CT13 -48.4 17.6 CL9 -47.8 10.9 A13 -48.9 8.1 B14 -49.1 14.9 D13 -49.2 5.4CT14 -48.1 14.9 A14 -48.9 14.9 B13 -48.9 8.1 D14 -49.0 4.1CT6 -48.2 8.1 B3 -48.6 6.8

CT12 -48.0 16.3CT18 -48.2 6.8avg. -48.2 12.8 avg. -47.8 10.9 avg. -48.9 11.5 avg. -48.9 10.0 avg. -49.1 4.7

CT10 -33.7 27.1 CL7 -33.6 21.7 A10 -33.9 10.9 B10 -33.9 8.1 D10 -33.7 6.8CT11 -33.6 19.0 CL8 -33.6 31.2 A11 -33.9 21.7 B11 -33.9 9.5 D11 -33.6 6.8

avg. -33.7 23.1 avg. -33.6 26.5 avg. -33.9 16.3 avg. -33.9 8.8 avg. -33.7 6.8CT4 -17.8 23.1 CL3 -17.9 141.1 A4 -18.2 130.3 B4 -18.2 10.9 D4 -17.7 13.6CT5 -17.8 19.0 CL4 -17.9 59.7 A5 -18.2 57.0 B5 -18.1 62.4 D5 -17.7 6.8

A6 -18.1 146.6 B6 -18.0 38.0

avg. -17.8 21.0 avg. -17.9 100.4 avg. -18.2 111.3 avg. -18.1 37.1 avg. -17.7 10.2CT7 0.2 33.9 CL5 0.2 149.3 A9 0.3 196.8 B7 0.3 104.5 D7 0.2 33.9CT8 0.2 21.7 CL6 0.2 149.3 A8 0.4 203.6 B8 0.3 162.8 D8 0.2 29.9CT9 0.2 48.9 A7 0.5 217.1 B9 0.3 63.8 D3 6.7 130.3avg. 0.2 34.8 avg. 0.2 149.3 avg. 0.4 205.8 avg. 0.3 110.4 avg. 2.4 64.7CT3 19.5 92.2a CL1 19.6 152.0 A1 19.6 217.1 B1 19.6 172.3 D9 13.3 173.7CT1 19.6 57.0 CL2 19.6 162.8 A2 19.6 207.6 B2 19.6 180.5 D12 13.3 190.0CT2 19.6 27.1 A3 19.6 210.3 D2 19.5 179.1

D1 19.6 181.8avg. 19.6 42.1 avg. 19.6 157.4 avg. 19.6 211.7 avg. 19.6 176.4 avg. 16.4 181.2

CT16 48.7 73.3 CL10 48.8 181.8 A15 49.4 211.7 B12 49.3 181.8 D6 49.1 199.5CT17 48.7 65.1 A12 49.6 230.7 B15 49.3 177.8 D15 49.2 192.7CT15 48.9 57.0avg. 48.8 65.1 avg. 48.8 181.8 avg. 49.5 221.2 avg. 49.3 179.8 avg. 49.2 196.1


(b) Steel grade: Class C [CAN/CSA-G40.20-98], Manufactured by: Company A (Canada), RHS designation: RHS 254x254x15.9

Specimen taken from: Seam weld Flat face of RHS Corner of RHSLocation C Location A Location B Location D

-34

°C0

°C-1

8 °C

-49

°C20

°C

Longitudinal Longitudinal LongitudinalTransverse Longitudinal Transverse

49 °C

Exterior face Interior faceExterior face Exterior face Exterior face Exterior face

interiornotch

exteriornotch

DD

AA

BB

Cweldseam

exteriornotch


C C

Tube (b) RHS 254x254x15.9

Cold-formedCompany A (Canada)

24

Table A3. CVN test results for cold-formed RHS 102x102x12.7 (Company B - Canada)


13TW -46.3 13.6 8LW -49.8 5.4 13T -49.2 8.1 8L -49.9 4.1 11B -46.9 2.7 11A -46.7 2.714TW -46.2 9.5 14T -48.9 6.8 12B -46.8 2.7 12A -46.2 4.115TW -47.2 10.8 15T -48.4 6.8avg. -46.6 11.3 avg. -49.8 5.4 avg. -48.8 7.2 avg. -49.9 4.1 avg. -46.9 2.7 avg. -46.5 3.4

16TW -34.8 10.8 9LW -35.3 10.8 16T -35.9 8.1 9L -34.4 4.1 13B -34.8 2.7 13A -34.6 4.117TW -34.5 23.0 10LW -35.3 6.1 17T -34.7 16.3 10L -34.7 5.4 14B -34.6 3.4 14A -35.3 5.418TW -35.8 13.6 18T -34.8 10.8 15B -35.9 4.1 15A -34.9 4.1avg. -35.0 15.8 avg. -35.3 8.5 avg. -35.1 11.7 avg. -34.6 4.8 avg. -35.1 3.4 avg. -34.9 4.5

10TW -19.3 28.5 6LW -19.9 8.1 10T -19.4 19.0 6L -19.6 6.8 8B -19.2 4.1 8A -18.9 8.111TW -19.3 16.3 7LW -20.1 6.8 11T -19.3 24.4 7L -19.6 6.8 9B -18.9 4.1 9A -19.3 6.812TW -19.2 20.3 12T -19.2 16.3 10B -18.9 5.4 10A -19.3 6.8avg. -19.3 21.7 avg. -20.0 7.5 avg. -19.3 19.9 avg. -19.6 6.8 avg. -19.0 4.5 avg. -19.2 7.27TW 0.3 27.1 5LW 0.3 10.8 7T 0.2 32.5 5L 0.3 13.6 6B 0.3 8.1 6A 0.1 94.98TW 0.3 31.2 8T 0.2 24.4 7B 0.2 19.0 7A 0.2 147.89TW 0.3 13.6 9T 0.2 23.0avg. 0.3 24.0 avg. 0.3 10.8 avg. 0.2 26.6 avg. 0.3 13.6 avg. 0.3 13.6 avg. 0.2 121.41TW 19.8 40.7 1LW 19.6 27.1 1T 20.0 59.7 1L 19.6 181.7 1B 20.1 137.0 1A 20.1 143.72TW 20.1 32.5 2LW 19.7 71.9 2T 19.9 62.4 2L 19.7 154.6 2B 20.1 29.8a 2A 20.2 151.93TW 19.9 29.8 3T 20.1 82.7avg. 19.9 34.3 avg. 19.7 49.5 avg. 20.0 68.3 avg. 19.7 168.2 avg. 20.1 137.0 avg. 20.2 147.84TW 45.4 105.8 3LW 45.9 146.4 4T 45.2 128.8 3L 45.7 179.0 3B 44.8 165.4 3A 44.7 179.05TW 45.3 94.9 4LW 46.2 146.4 5T 45.1 120.7 4L 45.7 179.0 4B 44.9 137.0 4A 44.6 155.96TW 45.3 74.6 6T 44.9 97.6 5B 44.9 149.2 5A 44.5 192.6avg. 45.3 91.8 avg. 46.1 146.4 avg. 45.1 115.7 avg. 45.7 179.0 avg. 44.9 150.5 avg. 44.6 175.8

note: aextraneous data pointExterior face Exterior face

Longitudinal Transverse Longitudinal Longitudinal Longitudinal

(c) Steel grade: Class C [CAN/CSA-G40.20-98], Manufactured by: Compnay B (Canada), RHS designation: RHS 102x102x12.7

Specimen taken from: Seam weld Flat face of RHSLocation ALocation C

Corner of RHSLocation B Location D

-49

°C-3

5 °C

-20

°C0

°C20

°C45

°C

Exterior face Exterior faceExterior faceExterior faceTransverse

interiornotch

transverse longitudinal

D DA

AB B

C

exteriornotch

exteriornotch

exteriornotch

C CTube (c) RHS 102x102x12.7

Cold-formedCompany B (Canada)

weldseam

note: corner of CVN specimen lacking due to offset weld seam location

25

Table A4. CVN test results for hot-rolled RHS 100x100x12.5 (Company C - Germany)


CT10 -45.6 94.9 CL10 -46.7 112.5 B13 -47.1 54.2 D11 -49.3 54.2CT11 -44.6 78.6 CL11 -44.8 55.6 B14 -45.7 54.2 D12 -47.3 131.5CT12 -44.6 74.6 CL12 -43.9 127.4 D13 -46.3 54.2avg. -44.9 82.7 avg. -45.1 98.5 avg. -46.4 54.2 avg. -47.6 80.0CT3 -35.4 115.2 CL3 -33.8 89.5 B10 -35.5 126.1 D4 -35.7 135.6CT6 -35.1 126.1 CL6 -34.4 113.9 B11 -35.4 135.6 D10 -35.7 127.4CT9 -34.4 92.2 CL9 -33.9 127.4 D3 -35.5 105.8avg. -35.0 111.2 avg. -34.0 110.3 avg. -35.5 130.8 avg. -35.6 122.9CT7 -19.1 126.1 CL7 -19.1 157.3 B7 -20.6 170.8 D9 -19.2 187.1CT8 -19.1 127.4 CL8 -18.5 173.5 B9 -19.9 160.0 D8 -19.4 113.9

B8 -19.1 155.9B3 -19.2 115.2

avg. -19.1 126.8 avg. -18.8 165.4 avg. -19.7 150.5 avg. -19.3 150.5CT1 0.1 160.0 CL1 0.1 241.3 B1 0.1 176.3 D1 0.1 181.7CT2 0.1 157.3 CL2 0.1 176.3 B2 0.1 180.3 D2 0.0 199.3

avg. 0.1 158.6 avg. 0.1 208.8 avg. 0.1 178.3 avg. 0.1 190.5CT4 20.6 168.1 CL4 20.6 227.8 B4 20.5 249.5 D5 20.4 250.8CT5 20.6 187.1 CL5 20.6 254.9 B5 20.5 252.2 D6 20.4 244.0

CT16 20.7 271.2 CL16 20.7 199.3 B6 20.5 269.8 D7 20.4 245.4avg. 20.6 208.8 avg. 20.6 227.3 avg. 20.5 257.2 avg. 20.4 246.8

CT14 48.2 216.9 CL14 47.9 329.5 B12 48.2 265.7 D15 48.4 244.0CT13 48.2 212.9 CL13 47.9 268.4 B15 48.3 268.4 D14 48.4 303.7CT15 48.2 227.8 CL15 47.7 314.5avg. 48.2 219.2 avg. 47.8 304.2 avg. 48.3 267.1 avg. 48.4 273.9

(d) Steel grade: Hot-rolled, Manufactured by: Company C (Germany), RHS designation: RHS 100x100x12.5

Specimen taken from: Seam weld Flat face of RHS Corner of RHSnote: Hot-rolled (NO SEAM WELD) Location C Location B Location D

-45

°C-3

5 °C

0 °C

-20

°C20

°C

Transverse

48 °C

Longitudinal Longitudinal LongitudinalExterior face Exterior face Exterior face Interior face

interiornotch

exteriornotchtransverse longitudinal

D DB B

C exteriornotch

C CTube (d) RHS 100x100x12.5

Hot-formedCompany C (Germany)

26

Table A5. CVN test results for hot-formed CHS 324x8.4 (Company D - Brazil)


P1 -73.9 41.4P2 -73.8 41.4P3 -73.5 37.3

avg. -73.7 40.0P16 -55.6 59.7P17 -55.6 43.4P18 -55.7 59.7avg. -55.6 54.2P4 -35.8 59.7P5 -35.6 61.7P6 -35.7 61.7

avg. -35.7 61.0P7 -21.3 62.4P8 -21.2 59.7P9 -21.1 59.7

avg. -21.2 60.6P10 -3.0 62.4P11 -2.9 61.0P12 -2.9 60.3avg. -2.9 61.2P13 19.6 62.4P14 19.6 62.4P15 19.6 62.4avg. 19.6 62.4

(e) Steel grade: Hot-formed, Manufactured by: Compnay D (Brazil),Circular hollow section designation: CHS 324x8.4

"Flat" face of CHSLocation A

-75

°C-3

5 °C

0 °C

-55

°C-2

0 °C

20 °C

Longitudinal Transverse LongitudinalExterior face Interior face

TransverseExterior face Exterior face Exterior face Exterior face

Longitudinal Longitudinal

Note: Subsized (5 x 10 x 55 mm) coupons used

exteriornotch

A

A

Tube (e) CHS 324.8.4

Hot-rolledCompany D (Brazil)

27

Table A6. CVN test results for "hot-rolled/cold-shaped" RHS 255x255x8.4 (Company D - Brazil)[shaped from hot-rolled CHS 324x8.4 parent tube]


T1 -73.3 10.8 L1 -73.9 27.8 OUT1 -73.9 5.4 IN1 -72.9 4.7T2 -74.0 24.4 L2 -74.0 28.5 OUT2 -73.7 4.1 IN2 -72.9 4.1T3 -74.1 25.8 L3 -74.1 23.0 OUT3 -73.3 10.2 IN3 -72.9 4.7

avg. -73.8 20.3 avg. -74.0 26.4 avg. -73.6 6.6 avg. -72.9 4.5T16 -55.6 40.7 L16 -55.6 44.7 OUT16 -55.2 35.3 IN16 -54.2 29.8T17 -55.6 48.1 L17 -55.4 44.1 OUT17 -54.8 32.5 IN17 -54.1 17.6T18 -55.1 59.7 L18 -55.3 55.6 OUT18 -54.3 35.3 IN18 -53.9 13.6avg. -55.4 49.5 avg. -55.4 48.1 avg. -54.8 34.3 avg. -54.1 20.3T4 -35.6 59.0 L4 -35.2 56.9 OUT4 -35.1 53.6 IN4 -34.8 51.5T5 -35.7 61.0 L5 -35.4 57.6 OUT5 -35.0 43.4 IN5 -34.6 51.5T6 -35.5 60.3 L6 -35.4 55.6 OUT6 -34.7 54.2 IN6 -34.4 51.5

avg. -35.6 60.1 avg. -35.3 56.7 avg. -34.9 50.4 avg. -34.6 51.5T7 -21.0 59.7 L7 -20.7 56.9 OUT7 -20.4 52.9 IN7 -20.1 52.9T8 -20.8 61.0 L8 -20.6 57.6 OUT8 -20.3 52.2 IN8 -20.0 51.5T9 -20.8 60.3 L9 -20.5 57.6 OUT9 -20.2 54.2 IN9 -19.7 53.6

avg. -20.9 60.3 avg. -20.6 57.4 avg. -20.3 53.1 avg. -19.9 52.7T10 -2.9 62.4 L10 -2.7 59.0 OUT10 -2.6 54.2 IN10 -2.3 54.2T11 -2.8 59.7 L11 -2.6 59.7 OUT11 -2.5 54.2 IN11 -2.3 53.6T12 -2.7 61.7 L12 -2.6 59.7 OUT12 -2.4 54.9 IN12 -2.2 53.6avg. -2.8 61.2 avg. -2.6 59.4 avg. -2.5 54.5 avg. -2.3 53.8T13 19.7 62.4 L13 19.7 61.7 OUT13 19.9 54.2 IN13 19.9 54.2T14 19.7 61.0 L14 19.7 61.7 OUT14 19.9 54.2 IN14 19.9 55.6T15 19.7 61.7 L15 19.8 59.7 OUT15 19.9 54.2 IN15 19.9 56.9avg. 19.7 61.7 avg. 19.7 61.0 avg. 19.9 54.2 avg. 19.9 55.6

(f) Steel grade: Hot-formed, Manufactured by: Company D (Brazil),RHS designation: RHS 255x255x8.4

Specimen taken from: Seam weld Flat face of RHS Corner of RHSnote: Hot-rolled (NO SEAM WELD) Location A Location B Location D

-75

°C-3

5 °C

0 °C

-55

°C-2

0 °C

20 °C

Longitudinal Transverse LongitudinalTransverse Longitudinal LongitudinalExterior face Interior faceExterior face Exterior face Exterior face Exterior face

interiornotch

exteriornotch

DD

A BB

exteriornotch


A A

Tube (f) RHS 255x255x8.4

Hot-rolled/cold-shapedCompany D (Brazil)

Note: Subsized (5 x 10 x 55 mm) coupons used

28

Table A7. CVN test results for cold-formed RHS 350x350x12.5 (Company E - France)


AT16 -74.9 19.0 AL10 -75.0 179.0 CT16 -75.0 19.0 CL10 -75.2 75.9 D15 -75.1 8.1 B15 -75.2 9.5AT17 -74.8 19.0 CT17 -74.9 17.6 D16 -75.2 20.3 B16 -74.9 3.4AT18 -74.9 16.3 CT18 -75.1 21.7avg. -74.9 18.1 avg. -75.0 179.0 avg. -75.0 19.4 avg. -75.2 75.9 avg. -75.2 14.2 avg. -75.1 6.4AT1 -50.7 21.7 AL1 -50.6 218.3 CT1 -50.5 24.4 CL1 -50.4 112.5 D1 -50.4 113.2 B1 -50.2 8.1AT2 -50.7 21.7 CT2 -50.5 23.7 D2 -50.3 119.3 B2 -50.1 16.9AT3 -50.7 24.4 CT3 -50.4 23.7avg. -50.7 22.6 avg. -50.6 218.3 avg. -50.5 24.0 avg. -50.4 112.5 avg. -50.4 116.3 avg. -50.2 12.5AT4 -36.0 24.4 AL2 -35.7 234.6 CT4 -34.1 36.6 CL2 -35.3 286.1 D3 -35.2 97.6 B3 -33.7 38.0AT5 -35.9 33.2 AL3 -35.7 225.1 CT5 -35.5 32.5 CL3 -34.3 292.9 D4 -35.4 158.6 B4 -34.1 28.5AT6 -35.8 27.1 CT6 -35.4 29.8 D5 -34.9 185.7 B5 -33.9 43.4avg. -35.9 28.2 avg. -35.7 229.8 avg. -35.0 33.0 avg. -34.8 289.5 avg. -35.2 147.3 avg. -33.9 36.6AT7 -20.9 32.5 AL4 -20.6 246.8 CT7 -20.6 43.4 CL4 -20.4 292.9 D6 -20.2 233.2 B6 -20.1 48.8AT8 -20.8 39.3 AL5 -20.6 237.3 CT8 -20.6 42.7 CL5 -20.4 >352 D7 -20.2 226.4 B7 -20.1 183.0a

AT9 -20.8 43.4 CT9 -20.4 44.1 D8 -20.2 233.2 B8 -20.1 62.4avg. -20.8 38.4 avg. -20.6 242.0 avg. -20.5 43.4 avg. -20.4 322.0 avg. -20.2 230.9 avg. -20.1 55.6

AT10 -0.2 67.8 AL6 0.2 238.6 CT10 -0.1 66.4 CL6 0.0 336.2 D9 0.2 231.8 B9 0.3 222.4AT11 -0.3 61.0 AL7 0.2 242.7 CT11 -0.1 56.9 CL7 0.2 332.2 D10 0.3 240.7 B10 0.3 238.6AT12 -0.1 61.0 CT12 -0.1 101.0a D11 0.3 246.8 B11 0.3 174.9avg. -0.2 63.3 avg. 0.2 240.7 avg. -0.1 61.7 avg. 0.1 334.2 avg. 0.3 239.8 avg. 0.3 212.0

AT13 19.9 70.5 AL8 19.9 241.3 CT13 19.9 88.1 CL8 19.8 317.3 D12 19.9 229.1 B12 19.9 252.2AT14 19.9 71.2 AL9 19.9 248.1 CT14 19.8 90.8 CL9 19.9 >352 D13 19.8 268.4 B13 19.8 244.0AT15 19.9 67.8 CT15 19.8 85.4 D14 19.8 259.0 B14 19.8 241.3avg. 19.9 69.8 avg. 19.9 244.7 avg. 19.8 88.1 avg. 19.9 335.0 avg. 19.8 252.2 avg. 19.8 245.9


Longitudinal Longitudinal LongitudinalExterior face Exterior face Exterior face Exterior face Exterior face Interior face

20 °C

Transverse Longitudinal Transverse

-70

°C-5

0 °C

-35

°C0

°C-2

0 °C

Location A Location C Location D Location B

(g) Steel grade: Cold-formed, Manufactured by: Compnay E (France), RHS designation: RHS 350x350x12.5

Specimen taken from: Seam weld Flat face of RHS Corner of RHS

B

B

C

C

D

D

Aweldseam

interiornotch

exteriornotchexterior

notch

Tube (g) RHS 350x350x12.5

Cold-formed/stress-relievedCompany E (France)

A Aexteriornotch


29

Table A8. CVN test results for cold-formed RHS 250x25012.5 (Company F - Finland)


AT1 -70.4 13.6 AL1 -70.1 317.3 CT1 -75.1 160.0 CL1 -72.1 160.0 D1 -71.4 14.9 B1 -70.9 8.1AT2 -70.2 8.1 AL2 -69.9 295.6 CT2 -71.8 5.4a CL2 -72.2 203.4 D2 -71.2 19.0 B2 -70.7 10.8AT3 -70.2 5.4 CT3 -71.8 146.4 D3 -71.0 12.2 B3 -70.5 10.8avg. -70.3 9.0 avg. -70.0 306.4 avg. -72.9 153.2 avg. -72.2 181.7 avg. -71.2 15.4 avg. -70.7 9.9AT4 -50.6 32.5 AL3 -50.1 >352 CT4 -50.4 173.5 CL3 -50.2 326.7 D4 -49.8 120.7 B4 -50.8 174.9AT5 -50.6 254.9 AL4 -49.9 >352 CT5 -50.4 162.7 CL4 -50.5 >352 D5 -49.6 141.0 B5 -50.9 176.3AT6 -50.3 138.3 CT6 -50.3 265.7 D6 -49.4 183.0 B6 -50.7 139.6avg. -50.5 141.9 avg. -50.0 >352 avg. -50.4 200.7 avg. -50.4 >339.4 avg. -49.6 148.2 avg. -50.8 163.6AT7 -35.8 272.5 AL5 -35.4 >352 CT7 -35.2 177.6 CL5 -35.6 330.8 D7 -35.3 54.2a B7 -35.5 189.8AT8 -35.4 56.9 AL6 -35.3 >352 CT8 -34.9 263.0 CL6 -35.5 >352 D8 -35.2 250.8 B8 -35.4 177.6AT9 -35.6 230.5 CT9 -35.8 160.0 D9 -35.1 216.9 B9 -35.3 197.9avg. -35.6 186.6 avg. -35.4 >352 avg. -35.3 200.2 avg. -35.6 >341.4 avg. -35.2 233.9 avg. -35.4 188.5

AT10 -20.9 172.2 AL7 -20.3 >352 CT10 -20.2 189.8 CL7 -19.9 >352 D10 -20.3 244.0 B10 -19.9 206.1AT11 -20.8 177.6 AL8 -20.1 >352 CT11 -20.2 185.7 CL8 -20.5 >352 D11 -20.1 227.8 B11 -20.9 208.8AT12 -20.7 28.5 CT12 -20.6 199.3 D12 -20.0 282.0 B12 -20.7 212.9avg. -20.8 126.1 avg. -20.2 >352 avg. -20.3 191.6 avg. -20.2 >352 avg. -20.1 251.3 avg. -20.5 209.2

AT13 -0.5 >352 AL9 -0.3 >352 CT13 -0.4 349.8 CL9 -0.2 >352 D13 0.1 233.2 B13 -0.1 276.6AT14 -0.5 >352 CT14 -0.3 259.0 D14 0.0 313.2 B14 0.1 238.6AT15 -0.4 183.0 CT15 -0.2 >352avg. -0.5 >295.6 avg. -0.3 >352 avg. -0.3 >320.3 avg. -0.2 >352 avg. 0.1 273.2 avg. 0.0 257.6

AT16 18.2 271.2 AL10 18.1 >352 CT16 18.1 301.0 CL10 18.0 >352 D15 17.9 321.3 B15 17.9 252.2AT17 18.2 233.2 CT17 18.0 273.9 D16 18.0 >352 B16 18.0 245.4AT18 18.2 249.5 CT18 18.1 >352avg. 18.2 251.3 avg. 18.1 >352 avg. 18.1 >309 avg. 18.0 >352 avg. 18.0 >336.6 avg. 18.0 248.8


(h) Steel grade: Cold-formed, Manufactured by: Company F (Finland), RHS designation: RHS 250x250x12.5

Specimen taken from: Seam weld Flat face of RHS Corner of RHSLocation A Location C Location D Location B

-70

°C-5

0 °C

-35

°C0

°C-2

0 °C

20 °C

Transverse Longitudinal Transverse Longitudinal Longitudinal LongitudinalExterior face Exterior face Exterior face Exterior face Exterior face Interior face

Tube (h) RHS 250x250x12.5

Cold-formedCompany F (Finland)

B

B

C

C

D

D

Aweldseam

interiornotch

exteriornotchexterior

notch

A Aexteriornotch


Cold Form Toughness CIDECT-1B-2_03

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Transcript of Cold Form Toughness CIDECT-1B-2_03