ISST 2007 ISST 2007 A New Prediction for A New Prediction for - - PowerPoint PPT Presentation

ISST 2007 ISST 2007 A New Prediction for A New Prediction for Deterioration eterioration

• f the Corrosion Protection System
• f the Corrosion Protection System
• f the Oil Storage Barges
• f the Oil Storage Barges

H.Sugimoto

Shipbuilding Research Centre of Japan (SRC)

Y.Horii

Japan Oil , Gas and Metals National Corporation (JOGMEC)

• 1. OUTLINE OF OIL STORAGE BARGES
• 1. OUTLINE OF OIL STORAGE BARGES

2.

• 2. DIAGNOSTIC SYSTEM FOR CORROSION

DIAGNOSTIC SYSTEM FOR CORROSION PROTECTION SYSTEM PROTECTION SYSTEM

• 3. ACCCELRATED AGING TEST DATA AND
• 3. ACCCELRATED AGING TEST DATA AND

ACTU ACTUAL DATA AL DATA

• 4. RESULTS OF PREDICTION
• 4. RESULTS OF PREDICTION
• 5. POTENTIAL SIMULATION OF CORROSION
• 5. POTENTIAL SIMULATION OF CORROSION

PROTECTION SYSTEM PROTECTION SYSTEM

Today’s Topics

2) Survey Program 2) Survey Program Once/ 12 years Once/ 12 years ＝＝＝> Planned Survey System lanned Survey System Once/ 25 years(max) Once/ 25 years(max) (Kamigoto (Kamigoto Barges) arges) １） Spe Special Su ial Survey rvey Old Old New New In 12 years In 12 years ＝＝＝> One / within 5 years ne / within 5 years (A (All B Barges) (Represent rges) (Representat ative Barge) ive Barge) In Dry Dock In Dry Dock ＝＝＝> In Dry Dock > In Dry Dock

• r Mooring Site
• r Mooring Site

Revision of the Rules(1997)

Kamigoto Oil Storage Base

Kamigoto base: 390Lx97Bx27.6Dx5 barges 880mlx5=4400ml Shirashima base: 397Lx82Bx25.4x8 barges 700mlx8=5600ml

Structure of Kamigoto Storage Barge

Oil il Se Sea w a water Ine nert g gas

Water Tank

Corrosion Protection System

Lo Location tion

System System

Oil st Oil storage tank

• rage tank

Upper T Upper T/E 250 250μm Middl Middle no pai no paint Bottom T/E 2 Bottom T/E 250μm Water tank Water tank T/E T/E/ 250 250μm + A + Aluminum a anode Si Side de an and bottom d bottom shell shell To Topside pside P/E 400 400μm Wa Wate terline rline P/E P/E 400 400μm +Alum +Aluminum Ano m Anode Immers Immersed T/E 400 ed T/E 400μm +Alum +Aluminum a m anode Upper deck Upper deck IZ 75 IZ 75μm +P/E +P/E 100 100μm

Deterioration Pattern of Total Corrosion Performance

Tim e Quality Paint+anode Full protection C orrosion Deterioration of paint Anoe depletion Full protection Repair １ ０ ０ ％ Tim e Tim e １ ０ ０ ％

Deterioration Diagnosis Flow

Accelerated Aging Test (Specimen) ・Paint

• Impedance
• Adhesion.
• Current density

Actual Barge Measurement ・Paint

• Impedance
• Adhesion.
• Current density

(paint resistance) ・Anode

• Weight reduction

Deterioration Curve

• Impedance
• Adhesion.
• Current

density (paint resistance, anode weight reduction) Paint deterioration curve Anode deterioration curve Estimation of Protection System Life Deterioration Curve for Actual Barge Matching with Test Data

• Paint resistance
• Anode-Weight reduction

Acceleration Factor

Impedance Data of Accelerated Aging Tests and Actual Tank

50 100 150 200 250 300 350 400 450 10 10

1

10

2

10

3

10

4

10

5

10

6

10

7

Impedance（Ωm

２）

Accelerated Aging Test(Days) Test Data for sea water tank T/E(250μm）

□ Actual Data

for sea water tank (Aug.2002)

Current Density Data of Accelerated Aging Tests and Actual Tank

50 100 150 200 250 300 350 400 450 1 2 3 4 5 6 7 8 9 10 11 12

Average Current Density(mA/m

2)

Accelerated Aging Test(Days) Test Data for sea water tank T/E250μ m

□ Actual Data for sea water tank (Aug. 2002) ○ Monitoring Data (2004)

Lower bound Upper bound

Paint Resistance Data of Aging Tests and Actual Tank Data

50 100 150 200 250 300 350 400 450 10 10

1

10

2

10

3

10

4

10

5

10

6

10

7

Paint Resistance(Ωm

２）

Accelerated Aging Test(days) Test Data for sea water tank T/E250μm

□ Actual Data for sea water tank (Aug. 2002) ○Monitoring Data (2004)

Lower bound Upper bound

Prediction of Loss of Anode Weight (Example)

5 10 15 20 25 30 35 40 45 50 2 4 6 8 10 12 14 10 20 30 40 50 60 70 80 90 100

■A c t u a l D a t a a f t e r 1 4 y e a r s □ A c t u a l D a t a a f t e r 9 y e a r s

Loss of Anode Weight（kg） Operation Years

Upper Water Tank（Ｎｏ．１Ｓ）

2007

(scheduled)

L

• s

s

• f

A n

• d

e W e i g h t （％）

Simulation Model for Outside Shell and Bottom Shell of Kamigoto No.2 Barge

c

• r

d i n a t e

• r

i g i n b

• u

n d a r y

• n

s e a w a t e r

Z X Y 1 3 . 5 ( m ) 1 . ( m ) 2 . ( m ) 1 . ( m ) 1 . ( m ) 1 3 . 2 ( m ) b

• u

n d a r y

• n

a i r 6 . ( m )

. 2 ( m )

S

i d e w a l l

• f

s h i p E l e m e n t N

• .

1

• 1

5

S a c r i f i c i a l a n

• d

e s ( L i n e E

l e m e n t R a d i u s : . 6 9 ( m ) L e n g t h : 2 . ( m ) E l e m e n t N

• .

1 2 7 7 1 2 7 8 B

• t

t

• m

w a l l

• f

s h i p E l e m e n t N

• .

1 5 1

• 2

3 R a d i u s : . 6 9 ( m ) L e n g t h : 2 . ( m ) E l e m e n t N

• .

1 2 8 1 , 1 2 8 2 R a d i u s : . 6 9 ( m ) L e n g t h : 2 . ( m ) E l e m e n t N

• .

1 2 7 9 , 1 2 8

① ② ③

Results of Potential Simulation

2 4 6 8 1 1 2 1 4 . 7 . 7 5 . 8 . 8 5 . 9 . 9 5 1 .

P

• t

e n t i a l (

• V

） D i s t a n c e （ｍ） P a i n t r e s i s t a n c e （Ωm

2

） 1 1

1

1

2

1

3

1

4

1

5

1

6

K a m i g

• t
• N
• .

2 l i n e ① Anode position

Estimation Curve for Determination of Paint Deterioration Condition by Potential Measurement

1 2 3 4 5

• 5

5 10 15 20 25 30 35 10

1

10

2

10

3

10

4

10

5

25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400

K a m i g

• t
• N
• .

2 L i n e ① ΔV = 6 6 * e x p (

• l
• g

( r ) / . 5 2 7 ）

Maximum Potencial Difference, ΔV（mV) (solid line） Paint Resistance log(r) （Ωm

2）

Accelerated Aging Test(Days) (broken line) Paint Resistance ｒ Lower bound Upper bound

Example of Test Specimens for Monitoring

Recovered Plate from Barge (250 φｍｍ） １５０ｍｍｘ７０ｍｍｘｔ

Setting of Test Specimen in Air Pipe of Water Tank

９-Upper Tanks: 9 specimens ３-Lower Tanks: 3 specimens Periodic Monitoring:

Visual inspection Impedance Current density Adhesion Potential

Ｃｏｎｃｌｕｓｉｏｎ

Proposed and examined:

(1) Master curves of deterioration of paint system by accelerated aging tests is defined. (2) Actual deterioration data of both painting and anode are collected. (3) Method of determine correlation between master curve by tests and actual barge data by measurement at dry-docked survey is established (4) Prediction of a life of present corrosion protection system of immersed portion of the Oil Storage Barges becomes possible. (5) Estimation curve to determine paint deterioration condition using potential measurement are established.