1

Corrosion Resistant Steel forCorrosion Resistant Steel forPitting Corrosion on COTsPitting Corrosion on COTs

of Crude Oil Carrierof Crude Oil Carrier

The NSGP®-1Nippon Steel’s Green Protect-1

Nov. 2008

2

0

1

2

3

4

5

6

7

8

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5

pH

Corro

sion

Rate

mm

/yea

r

← Conventional Steel

NaCl 10wt.%30℃

Air OpenStagnant

n=3

↓ Target0

1

2

3

4

5

6

7

8

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5

pH

Corro

sion

Rate

mm

/yea

r

← Conventional Steel

NaCl 10wt.%30℃

Air OpenStagnant

n=3

↓ Target

Outline of the NSGP®-1A typical example of chemical analysis, AH32 （ mass%)

Chemical composition of NSGP®-1 meets the IACS rule

C Si Mn P S Al Ti Ceq

NSGP®-1 0.124 0.331Conventional 0.140 0.20 1.09 0.018 0.006 0.031 0.014 0.322

IACS Standard ≦0.18 ≦0.5 0.9～1.6 ≦0.035 ≦0.035 ≧0.02 ≦0.02 ≦0.36

meets IACS Standard (including all alloy elements)

NSGP®-1 provides superior corrosion resistance (NaCl 10wt.% pH around 0.8)

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

3

NSGPNSGP®-1 -1 has been applied to actual vessel(All COT bottom have been built with NSGP-1)

NSGPNSGP®-1 -1 has been applied to actual vessel(All COT bottom have been built with NSGP-1)

Ship 　 TAKAMINE (Built by Mitsubishi Heavy Industry) Construction completed with no problem #3 and #4 COTs : without painting

1st Dock inspection : at 2.3 year after launching

1P

1C

1S

1P

1C

1S

2P

2C

2S

2P

2C

2S

3P

3C

3S

3P

3C

3S

4P

4C

4S

4P

4C

4S

5P

5C

5S

5P

5C

5S

FWD

NSGP®-1 without Painting

4

Very low frequencyOnly shallow pits

NSGP®-1 Inspection result after 2.3 years service

No need to repair

7 7 7 20 4 270

200

400

600

800

1000

1200

1400

3P 3C 3S 4P 4C 4S

Pit C

ount

le

ss th

an 4

mm

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

2.3 years

0

2

4

6

8

10

12

3P 3C 3S 4P 4C 4S

No Need to Repair

0

2

4

6

8

10

12

3P 3C 3S 4P 4C 4S

Max

pit

dept

h m

m

No Need to Repair

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

2.3 years

0

2

4

6

8

10

12

3P 3C 3S 4P 4C 4S

No Need to Repair

0

2

4

6

8

10

12

3P 3C 3S 4P 4C 4S

Max

pit

dept

h m

m

No Need to Repair

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

2.3 years

5

1P

1C

1S

1P

1C

1S

2P

2C

2S

2P

2C

2S

3P

3C

3S

3P

3C

3S

4P

4C

4S

4P

4C

4S

5P

5C

5S

5P

5C

5S

FWD

NSGP®-1 without Painting

2nd InspectionAfter 4.2 years service

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

Inspected Area3P & 4P

6

NSGPNSGP®®-1-1 No pit over 4mm depth even after 4.2 years

No pit over 4mm depth

NSGP® -1NSGP® -1

00

200

400

600

800

1000

1200

1400

3P 4P

Pit C

ount

Ove

r 4m

mde

pth

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

4.2 years

0

7

Pit depth after 2.3 and 4.2 years service

Maximum pit depth did not change with time

COT #4P

COT #3PMax. 2.6mm : 2.3 years

↓Max. 2.5mm : 4.2 years

Max. 3.1mm : 2.3 years↓

Max. 3.1mm : 4.2 years

8

Depth at 2.3 and 4.2 years= absolutely proportional

↓ No change in pit depth

Pit growth stoppedafter COT cleaning and drying

Pitting Corrosion Growth Termination

NSGP® -1NSGP® -1

Bottom Plate Thickness ↑

0123456789

10111213141516171819

0 1 2 3 4 5 6 7 8 9 10 1112 1314 1516 171819

Pit Depth after 2.3 years service / mm

Pit D

epth

afte

r 4.2

yea

rs s

ervic

e / m

m

COT Cleaning and drying have beencarried out at after 2.3 years service

Repair Free

3P

4P

Pits to be repairedby welding

Pits to be repairedby Painting

Apparently Pitting Growthhas been TERMINATED

NSGP® -1NSGP® -1NSGP® -1NSGP® -1NSGP® -1NSGP® -1NSGP® -1NSGP® -1

Bottom Plate Thickness ↑

0123456789

10111213141516171819

0 1 2 3 4 5 6 7 8 9 10 1112 1314 1516 171819

Pit Depth after 2.3 years service / mm

Pit D

epth

afte

r 4.2

yea

rs s

ervic

e / m

m

COT Cleaning and drying have beencarried out at after 2.3 years service

Repair Free

3P

4P

Pits to be repairedby welding

Pits to be repairedby Painting

Apparently Pitting Growthhas been TERMINATED

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

9

NSGP®-1 Potential for Repair-free

NSGP®-1 + COT Cleaning → Repair-free

0

2

4

6

8

10

12

0 5 10 15 20 25 30 35

Ship Age / years

0

2

4

6

8

10

12

0 5 10 15 20 25 30 35

Ship Age / years

No need for maintenance during a whole ship life with NS-GP1

Observed Results

No n

eed

to

Repa

ir

Pit Growth Terminatesat Dock inspection

[Found by SR242]

Observed Max. Corrosion Depthwith NS-GP1

Less than 4mm

0

2

4

6

8

10

12

0 5 10 15 20 25 30 35

Ship Age / years

Pit

Dept

h / m

m

Repair Free during whole ship life with NSGP®-1

Repa

ir-fre

e

COT Cleaning

NSGP® -1NSGP® -1NSGP® -1NSGP® -1

1st 2ndCOT Cleaning

10

Summary of the NSGPSummary of the NSGP®®-1-1Summary of the NSGPSummary of the NSGP®®-1-1

11 ）） Confirmed excellent corrosion resistanceConfirmed excellent corrosion resistance in actual VLCC in actual VLCC

2) Potential for 2) Potential for repair free for whole ship liferepair free for whole ship life 33 ）） Excellent mechanical properties and weldabilityExcellent mechanical properties and weldability

44 ）） No dependence on condition of applicationNo dependence on condition of application 　　　　

11 ）） Confirmed excellent corrosion resistanceConfirmed excellent corrosion resistance in actual VLCC in actual VLCC

2) Potential for 2) Potential for repair free for whole ship liferepair free for whole ship life 33 ）） Excellent mechanical properties and weldabilityExcellent mechanical properties and weldability

44 ）） No dependence on condition of applicationNo dependence on condition of application 　　　　

11

Practical Advantages of the NSGPPractical Advantages of the NSGP®®-1-1 for Ship Owners for Ship Owners

Practical Advantages of the NSGPPractical Advantages of the NSGP®®-1-1 for Ship Owners for Ship Owners

By using NSGPBy using NSGP®®-1 for COT of crude oil carriers, -1 for COT of crude oil carriers, • Great improvement in the safety and reliabilityGreat improvement in the safety and reliability of marine vessel of marine vessel

s and ins and in the protection of the global environment the protection of the global environment• Corrosion protective Corrosion protective coating is not necessarycoating is not necessary, as do coating ag, as do coating ag

ents and volatile organic compounds.ents and volatile organic compounds.• Repair freeRepair free

↓↓

NYK decided to use the NSGPNYK decided to use the NSGP®®-1-1on all new VLCCs from now onon all new VLCCs from now on

By using NSGPBy using NSGP®®-1 for COT of crude oil carriers, -1 for COT of crude oil carriers, • Great improvement in the safety and reliabilityGreat improvement in the safety and reliability of marine vessel of marine vessel

s and ins and in the protection of the global environment the protection of the global environment• Corrosion protective Corrosion protective coating is not necessarycoating is not necessary, as do coating ag, as do coating ag

ents and volatile organic compounds.ents and volatile organic compounds.• Repair freeRepair free

↓↓

NYK decided to use the NSGPNYK decided to use the NSGP®®-1-1on all new VLCCs from now onon all new VLCCs from now on

12

Draft SOLAS amendment on protection of COT of tankers accepted usage of alternative means (W.G. of DE51 ‘08.2)

What is going on at IMO?What is going on at IMO?What is going on at IMO?What is going on at IMO?

3 All cargo oil tanks of crude oil tankers shall be: .1 coated during the construction of the ship in accordance with the Performance standard for protective coatings for cargo oil tanks of crude oil tankers, adopted by the Maritime Safety Committee by resolution ….or

.2 protected by alternative means of corrosion protection, the effectiveness of which shall be no less than the objectives ....

4 The Administration may exempt a crude oil tanker from the requirements of paragraph 3 of this regulation to allow the use of novel prototype alternatives to the coating system specified in paragraph 3.1, ….

NSGPNSGP®®-1 could be an alternative mean-1 could be an alternative mean

13

NYK LINE

Hidehiko Sato : hidehiko_sato@jp.nykline.com

Nippon Steel Corporation

Tatsuro Nakai : nakai.tatsuroh@nsc.co.jp

NSGPNSGP®®-1-1Nippon Steel’s Green ProtectNippon Steel’s Green Protect®® -1 -1

NSGPNSGP®®-1-1Nippon Steel’s Green ProtectNippon Steel’s Green Protect®® -1 -1

Note:

NSGP: is a registered trade mark or trade mark of Nippon Steel Corporation in Japan and other countries.