Post on 20-Jan-2017
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
1
Machining of Austempered Ductile Iron Challanges and Solutions- Austempering a technology for substitution -
Prof. Dr.-Ing. Dr.-Ing. E. h. Dr. h. c. Dr. h. c. Fritz KlockeDr.-Ing. Dipl.-Wirt.-Ing. Benjamin DöbbelerDipl.-Ing. Sven Lung
Bevilacqua, 6. and 7. October 2016
Agenda
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
3
Summary5
Investigation of Contact Fatigue for ADI1200, ADI900 and AST4
Improvement of the ADI machining process 3
Machining properties of ADI2
Fundamentals in Metal Cutting1
Shear zones during chip formation
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
4
Primary shear zone: Transition from workpiece structure to chip structure
The material is getting deformed to a chip due to simple shear in the primary shearzone.
Secondary shear zone: Tensile load in combination with perpendicularly pressure and high temperature leads to strong deformation at the rake and flank face
The shear in combination with high pressure leads to a strong deformation in the border areas of the rake face and the flank face (secondary shearzone).
The boundary conditions during chip formation:- High temperatures in the contact zone (approx. 770-
1100°C) - High deformation rate (approximately 104 1/s)
Tool
Rake face A
Chip
Work piece
Secondary shear zone (flank face)
Secondary shear zone (rake face)Primary shear
zone
βo
rb
Flank face A
Cutting speed vc
Feed rate f
Resolution of the Effective cutting speed and the resultant force
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
5
Fz: Resultant forceFc: Cutting forceFf: Feed forceFp: Passive force
vc: Cutting speedvf: Feed velocityve: Effective cutting speed
Feed motion(Tool)
vc
vf
ve
Fc
Fp
Ff
Rotational speed(Work piece)
Fz
The vector of the effective cutting speed can be partitoned into two vectors Cutting Speed: In rotation direction Feed velocity: In feed direction
The machining force Fz can be partitioned in different components. Cutting force Fc: Force in cutting speed direction Feed force Ff: In Feed direction Passive force Fp
Agenda
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
6
Summary5
Investigation of Contact Fatigue for ADI1200, ADI900 and AST4
Improvement of the ADI machining process 3
Machining properties of ADI2
Fundamentals in Metal Cutting1
Wear Formation when Turning Ductile Iron
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
7
GJS-900-7(ADI 900)
f = 0,2 mmap = 1 mm
vc = 140 m/mint = 18,8 minG
JS-900-7
Criterion : Flank & Crater wear
Austenitic-FerriticMatrix
GJS-700-2
Criterion : Flank wear
PerliticMatrix
GJS-400-15 Crater wearFlank wear
Criterion : Flank wear
FerriticMatrix
Cutting time
Cutting time
GJS-700-2(GGG70)
f = 0,2 mmap = 1 mm
vc = 260 m/mint = 6,8 min
GJS-400-15(GGG40)
f = 0,2 mmap = 1 mm
vc = 360 m/mint = 12,6 min
Wear mechanisms of Quenched and Temperd Steel and ADI
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
8
Cutting parametersHM-K10vc = 70 m/min
f = 0,25 mmap = 1,5 mm
Dry Machiningtc = 8,00 min
Source: C. Klöpper, Phd-Thesis RWTH Aachen
500 µm
42C
rMo4
+QT
GJS
-900
-7
500 µm
500 µmetched
500 µmetched
Comparison of the Cutting Forces
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
9
1000
1500
2500
3000
1 2 3 4
Cutting Force Oscillationvc = 100 m/min, f = 0.2 mm
Cutting Time tc / ms
500
2000
Cut
ting
Forc
e F c
/ N
42CrMo4VEN-GJS-900-7
0
100
200
300
400
500
0 0.1 0.2 0.3 0.4Undeformed Chip Thickness / mm
Related Cutting Force Fc‘ / (N/mm)vc = 100 m/min (150 m/min for conventional GJS)
600
42CrMo4V
EN-GJS-400-15EN-GJS-700-2
EN-GJS-900-7
Rel
ated
Cut
ting
forc
e F‘
c / N
/mm
Fc' = 1133.3 h0.7006
Fc' = 1112.8 h0.6222
Fc' = 1099.6 h0.5732
Fc' = 2291.4 h0.9124
Cross section ofundeformed chip
Work piece
Toolb
fv
A ap
f
kr
Direction of rotation
h fv
kr
𝐹 𝑐 ′=𝐹 𝑐 /𝑏
𝐴=𝑏⋅ h=𝑎𝑝 ⋅ 𝑓Related cutting force
Stages of the chip formation of ADI materials
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
10
First contact Start of deformation Crack initiation Sliding
End of sliding
Segmentation
Crack initiationStart of deformation
Mat
eria
l spe
ed /
m/m
in
0
12,5
25
37,5
50
62,5
75
90
Source: C. Klöpper, Phd-Thesis RWTH Aachen
Influence of Material Hardness on Wear and Tool life in dry Turning
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
11
External longitudinal turning (Criterion: KT = 75 µm; VBmax = 300 µm): vc = 160 m/min; f = 0.2 mm; ap = 2 mm; dry; κr = 95°; αo = 6°; λs = -6°; γeff = -6°HC-K20,Coating: Ti(C, N)/ Al2O3, CNMA 120408;
ADI 900; T = 13,5 min
600 µm
GJS 700-2; T = 26,8 min
600 µm
Tool life T / min0 5 10 15 20 25
GJS 700-2 100 %
ADI 1200 15 %
GJS 900-7 50 %
ADI 1200; T = 3 min
600 µm600 µm
200 µm600 µm200 µm
ADI 1200; T = 3 min (etched)
Agenda
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
12
Summary5
Investigation of Contact Fatigue for ADI1200, ADI900 and AST4
Improvement of the ADI machining process 3
Machining properties of ADI2
Fundamentals in Metal Cutting1
Optimisation of Tool life in External longitudinal turning using Emulsion
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
13
Em
ulsi
on
ADI 900
GJS 700-2
ADI 1200
Tool
life
T /
min
Cutting speed vc / (m/min)
Dry ADI 900
GJS 700-2
ADI 1200
10
100
2
30
60 40080 200 300
8
6
4
20
ADI 1200
ADI 900
GJS 700-2
= 6°= -6°= -6°
o
eff
ls
vc
fap
kr
HC-K20CNMA 120408Ti(C, N)/ Al2O3
= var.= 0,2 mm= 2 mm= 95°
External longitudinal turning (KT = 75 µm; Vbmax = 300 µm):
Increase of Material removal rate and Tool life by adapted Feed, Cutting speed and Tool geometries
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
14
Process: External turning (Emulsion)
Material: ADI 900Tool holder: MCLNL2525Tool geometry: CNMA/ CNMG 120408
Material removal rate: Q = vc • ap • fDepth of cut: ap = 2 mmCutting speed: vc = 240 / 320 m/minFeed: f = 0,2 / 0,4 mm
Mat
eria
l rem
oval
rate
Q /
cm3 / m
in
0
50
100
150
200
0
3
6
12
Tool
life
T /
min
9
rb = 60 µm
eff = -6°
o = 6°CNMA
eff = -6°
rb = 60 µm
o = 6°
eff = -1°12°
250 µm
CNMGeff = -1°
T =
9.4
min
vc = 320 m / minf = 0.2 mm
Q =
128
cm
3 /m
in
T =
7 m
in
vc = 240 m / minf = 0.4 mm
Q =
192
cm
3 /m
in
T =
10 m
in
T =
11 m
in
Q = + 50 %
T ≈ + 36 %
Increase of Tool life in Turning ADI 900 by Material-sided optimisation
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
15
5
10
15
20
Tool
life
T /
min
Wall thickness: 20 mm
Wall thickness: 30 mm
Wall thickness: 60 mm
Wall thickness: 90 mm
Nic
kel-C
onte
ntM
olyb
deni
um-C
onte
nt
Con
tent
of a
lloyi
ng e
lem
ents
/ %
0
1,0
2,0
3,0
4,0
0
External longitudinal turning (Tool life criterion: KT = 75 µm, VBmax = 300 µm):vc = 160 m/min; f = 0.2 mm; ap = 2 mm; dry; κr = 95°; αo = 6°; γeff = -6°; λs = -6°; MCLNR 2525M12; HC-K20, Coating: Ti(C, N)/ Al2O3, CNMA 120408;
Scatter from average value to maximum and minimum
Influence of Heat Treatment on Tool life when turning ADI
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
16
0 2 4 6 8 10 12 14 16
Haltezeit Salzbad: 180 min
Tool life T / minExternal longitudinal turning (ADI 900; dry; Criterion: KT = 75 µm, VBmax = 300 µm):Cutting speed: vc = 160 m/minFeed: f = 0.2 mmDepth of cut: ap = 2 mm
Cutting material: HC-K20Cutting insert: CNMA 120408Coating: Ti(C, N)/ Al2O3
Setting Angle: kr = 95°Clearance Angle: o = 6° Inclination Angle: ls = -6°
Austempering time: 30 min
Austempering time: 60 min
Austempering time: 90 min
Austempering time: 120 min
Austempering time: 180 min
Influence of the casting skin on cutting forces in roughing operations of ADI 900
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
17External longitudinal turning (ADI 900): vc = 240 m/min; f = 0.2 mm; ap = 2 mm; Emulsion; kr = 95°; o = 6°; ls = -6°; HC-K20, Coating: Ti(C,N)/ Al2O3, CNMG 120408 (eff = -1°);
Casting skin
Core material
T = 10 min
T = 10 min
1 mm
1 mm
Cut
ting
forc
es F
c / N
Cut
ting
forc
es F
c / N
Am
plitu
de ≈
700
N
500
1000
1500
0
Am
plitu
de ≈
70
N
500
1000
1500
0 t = 0,5 s
t = 0,5 s
Optimization of the roughing process of ADI 900 by using adapted tools
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
18External logitudial turning (ADI 900, Emulsion, Criterion: VB = 200 µm): vc = 240 m/min; f = 0,2 mm; ap = 2 mm; kr = 95°; o = 6°; ls = -6°; MCLNR 2525M12; Coating: Al2O3 / Ti(C, N), CNMx 120408
Tool life T / min0 2 4 6 8 10 12 14
Comb cracks
Tcast skin = 10 min 1 mm
HC-K20, eff = -1°
HC-K20, eff = -6°
HC-K15, eff = -6°
HC-K15, eff = -6°
HC-K15, eff = -1°
HC-K20, eff = -1°
HC-K20, eff = -6°
Core material
Core material
Cast skin
Cast skin
Cast skin
Cast skin
500 µm
Agenda
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
19
Summary5
Investigation of Contact Fatigue for ADI1200, ADI900 and AST4
Improvement of the ADI machining process 3
Machining properties of ADI2
Fundamentals in Metal Cutting1
Project Overview
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
20
Evaluation of Test Results
Analysis of Wear
Calculation ISO6336
The aim of the project is to determine the contact fatigue of different ADI types (JS/900-8, JS/1200-3) and casted steels (AST)
by disk-on-disk and back-to-back testing
Investigation of Contact Fatigue
Disk-on-Disk
Back-To-Back
Aim
Quality of Specimen
Geometry & Roughness
ISO 6336Teil 3
ISO 6336Teil 2
ISO 6336Teil 1
SN-Curves: Comparison of Variants ADI900 and ADI1200
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
21
Damage ADI900
Run Out ADI900
Disk-on-Disk Testa = 42,05 mms1 = -28 %n = 3000 min-1
QOil = 1,5 l/minTOil,in = 90 °COil: FVA3 A 4% Anglamol
Specimenmaterial: ADI1200material: ADI900d1/2 = 42,05 mmRbal1/2 = ∞/166 mmRz ≈ 3 μm
100000 1000000 10000000 100000000400
800
1600
Load Cycles / x106He
rtzi
an C
onta
ct P
ress
ure
/ MPa
Damage ADI1200
Run Out ADI1200SN-Curve ADI900SN-Curve ADI1200
Agenda
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
22
Summary5
Investigation of Contact Fatigue for ADI1200, ADI900 and AST4
Improvement of the ADI machining process 3
Machining properties of ADI2
Fundamentals in Metal Cutting1
Summary
Austempering, A Technology for Substitution
ADI DAYS 2016 6th – 7th October Minerbe
23
Tool life criterion by machining of ADI is the flank and crater wear. In comparison to a quenched and tempered ADI has a more abrasive tool wear. The dynamic tool load due to the chip formation leads to material fatigue of the tool. The thermal tool load can be reduced by using emulsion. The cutting speed should be decreased and the feed rate increased to achieve a high
tool life A high molybdenum content leads to a higher tool life scatter Machining the casting skin leads to a higher dynamic tool load due to the different
material allowance