SA 387

API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

1

CONTENT Introduction Comparision

of Standards

Technical

Issues

Particular

approach for heavy plates

Conclusions


2

SA 387 gr.11 : Cl.1 vs. Cl.2 Industeel Production 

Lower thickness range ( < 3")

SA 387 gr.11 Cl.1 ¾ 200 T en 2002 ¾ 300 T en 2003 SA 387 gr.11 Cl.2 ¾ 1600 T en 2002 ¾ 1600 T en 2003 

Higher thickness range ( > 3") ¾

exclusively SA 387 gr.11 Cl.2


3


of Standards

Technical

Issues

Particular


Conclusions


4

STANDARDS & CODES

European standard EN 10028-2 vs. ASTM A387

13 Cr Mo Si 5-5

A 387 Gr 11

SAME MATERIAL SAME PURPOSE Difference of definition Difference of requirements


5

STANDARDS & CODES

13 Cr Mo Si 5-5 S: P: Ni: Cu: N:

A 387 Gr 11

0.005 max 0.015 max < 0.3 < 0.3 < 0.012

S: P: Ni: Cu: N:

Thick.

YS 0.2

UTS

<60

310

480-630

60- 100

300

480-560

<60

400

510-690

60-100

390

500-680

100-250

380

490-670

A% Thick.

NT

QT

0.035 max 0.035 max as SA 20 (≤ 0.40) as SA 20 (≤ 0.40) none

20

YS 0.2

UTS

Class 1

240

415-585

Class 2

310

515-690

Degressivity of tensile properties with thickness in EN. Acknowledged difference between QT & NT in EN API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

A%

6

STANDARDS & CODES

13 Cr Mo Si 5-5 Complementary requirements on tensile properties Extract of Table 4

Proof strength as a function of t°C

thickness

50

100

150

200

250

300

350

400

450

500

< 60

300

285

272

260

250

240

231

223

215

-

60 - 250

290

276

263

252

241

232

224

216

208

-

This part of the standard is not informative, this is an actual requirement The values are similar to those required by the ASME code In practice, high temperature yield strength values can be met. This is not true for tensile strength. API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

7

STANDARDS & CODES

13 Cr Mo Si 5-5 vs. ASME requirements SA387g11 cl2 Yield strength as a function of temperature according to ASME and European codes Sy ASME SA387g11cl2

Sy EN10028.2

320 310 300 290 280 270 a 260 P M n 250 i y S 240

230 220 210 200 190 180 0

50

100

150

200

250

300

350

400

450

500

550

600

Temperature in °C


8

STANDARDS & CODES

Actual values vs. ASME requirements SA387g11 Hot tensile tests 95 to 121 mm plate thickness Total tempering parameter 20400 Rp02

Rm

Sy

Su

550

500

450

400

) a P M (

s 350 s e r t S

300

250

200

150 300

350

400

450

500

550

Temperature (°C)


9


of Standards

Technical

Issues

Particular


Perspectives

in Europe

Conclusions


10

TECHNICAL ISSUES

REVERSIBLE TEMPER EMBRITTLEMENT Step Cooling A387g11 cl2

14 12 10 8

J 4 5 a t l e D

6 4 2 0 100

110

120

130

140

150

160

170

180

-2 -4 -6

J Factor

For Phosphorus levels typical of Industeel production (<0.010%, target < 0.007%), there is no real influence of J-factor API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

11

TECHNICAL ISSUES

CREEP CRACKING : MPC FACTOR 0,11
CLASS 2 0 1 , C 0 P C < i M H

C L o < 0 , M 10 P C

Determine composition & class

Refine Joint design

Conv. Joint design

Conv. Joint design Q+T and Cont.Temper

.06-.08C% Filler Low Heat Input

06-.08C% Filler Moderate Heat Input

06-.08C% Filler Moderate Heat Input

PWHT 1300°F

PWHT 1275°F

PWHT 1250°F

NO PROBLEM OF TENSILE PROPERTIES DUE TO ACCELERATED WATER COOLING PROCESS API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

12

TECHNICAL ISSUES

CREEP CRACKING : MPC FACTOR INDUSTEEL production respects

MPC-7<0,5

BUT Æ MPC-5<2,4 is almost impossible to guarantee

THE Reason is NIOBIUM measurements MPC-5 requires Nb<1,5ppm OUR Nb residuals are only detected above 2ppm

What’s the real influence of Nb ?

How can we measure <2ppm ?


13

TECHNICAL ISSUES

CREEP CRACKING : role of phosphorus Creep rupture elongation of A387 gr11 at 500°C 50

45

40

P=0,007

35

30

% A 25 R

Série1 Série2

20

15

P=0,012 10

5

0 1000

10000

Time (h) API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

100000

14

TECHNICAL ISSUES

CREEP STRENGTH


15

TECHNICAL ISSUES

DISBONDING Weld overlay - all results 1,25Cr-1Mo

2,25Cr-1Mo

3Cr-1Mo

2,25Cr-1Mo-V

3Cr-1Mo-V

70 60 50

A : 225+6 ; 454°C ; 180bar B: 254+6 ; 454°C ; 150bar C: 200+6 ; 454°C ; 150bar D: 150+6 ; 454°C ; 150bar

40 30 20 10 0 100

200

D

300

C

B

A

400

500

600

700

H2 cal (ppm)


16

TECHNICAL ISSUES

DISBONDING SA 387 gr.11 would appear to be slightly more sensitive than SA 387 gr.22 Possible reason : Greater hydrogen trapping in SA 387 gr.22

In both cases, low CARBON content (0.15% max) is essential to protect against the Disbonding Risk: softening of the structure at the interface. API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

17

TECHNICAL ISSUES

CONCLUSIONS The problems normally encountered are : Creep Ductility Step cooling resistance reversible Temper Embrittlement

LOW P CONTROL IS ESSENTIAL TO LIMIT THESE PROBLEMS J factor target for INDUSTEEL is most of the time < 120-150 This value should help to select high cleanliness steels • For the %P content • For Mn+Si+Sn% considered as increasing P segregation API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

18


of Standards

Technical

Issues

Particular


Conclusions


19

PARTICULAR APPROACH FOR HEAVY PLATES Industeel Production, HDS projects in 2003/2004 (> 3") Belgium ¾ 188 T, 118mm, KCV –18°C, PWHT 660°C/16h France ¾

225 T, 109mm, KCV –18°C, PWHT 670°C / 13h

Saudi Arabia ¾ 132 T, 78mm, KCV –18°C, PWHT 665°C / 16h ¾ 116 T, 96mm, KCV –18°C, PWHT 680°C/18h ¾ 500 T, 150mm, KCV –18°C, PWHT 670°C / 16h South Korea ¾ 635 T, 134mm, KCV –18°C, PWHT 670°C / 17h China ¾ ¾

260 T, 160mm, KCV +20°C, PWHT 675°C / 26h 200 T, 95mm, KCV –10°C, PWHT 690°C/20h

¾

700 T, 180mm, KCV –7°C, PWHT 675°C / 17h

USA


20

PARTICULAR APPROACH FOR HEAVY PLATES For high thickness (> 4"), TOUGHNESS is the main issue 

Toughness guarantees (54/47J) limited to –18°C / -10°F



PWHT almost always < 690°C / 1275°F



WHY ? slower cooling rate leads to a mixed bainite – ferrite/pearlite microstructure ¾

excessive heat treatment leads to coarsening of carbides and enrichment in Mo ¾


21

IRREVERSIBLE TEMPER EMBRITTLEMENT

CCT Diagram of GR11

P355Q Example of a 200 mm thick plate Quenched Microstructure contains a significant rate of Perlite + Ferrite


22

PARTICULAR APPROACH FOR HEAVY PLATES

PRESENCE OF FERRITE + PERLITE

Creation and precipitation of CARBIDES (M 23 C 6 , M 6 C, M 2 C)

UNSTABLE @ High Temperature

Carbide growth

Embrittlement


23

PARTICULAR APPROACH FOR HEAVY PLATES 3 Parameters to be controlled

F+P Content Carbide coarsening Grain Size

EFFECT OF PWHT+Tempering on Grade 11 Toughness


24

PARTICULAR APPROACH FOR HEAVY PLATES STATISTICAL DATA ON PWHT EFFECT 180 160 140 120 S 100 E L U O J 80

60

33 J

40 20 0 600

620

640

660

680

700

720

Temperature of SR during 10h (°C)

Sensitive area very often targeted by manufacturers API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

25

PARTICULAR APPROACH FOR HEAVY PLATES


26

PARTICULAR APPROACH FOR HEAVY PLATES 21500

21000

-29°C / 54J Iincreasing testing temperature 20500

20000

t g o l + 0 2 ( T r e t e m a r a p g n i r e p m e T

19500

19000 50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

Plate thickness in mm


27


of Standards

Technical

Issues

Particular


Perspectives

in Europe

Conclusions


28

CONCLUSIONS

Cl.2

is more widely used than Cl.1

 Above

2”, SA 387 gr.11 Cl.2 is provided as NACT / QT

For

improved resistance to embrittlement, low P levels are essential For

high thickness (> 4”), toughness is the primary concern

 At

such thicknesses, it is necessary to limit the maximum tempering parameter This

may require tempering below PWHT, and performing PWHT < 690°C API Roundtable on 1 1/4Cr , ATLANTA, May 18h 2004

29

SA 387

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