GB 9948 석유 크래킹 이음매없는 강철 튜브

Sort Code

Manufacturing Method

Minimum Wall Thickness    S_min

Tolerance

Common Level

High Level

W-H

Hot Rolling(Extrusion)

≤4.0

+0.90

0

+0.70

0

＞4.0

+25%S_min

0

+22%S_min

0

W-C

Cold Drawn(Rolling)

≤3.0

+0.6

0

+0.4

0

＞3.0

+20%S_min

0

+15%S_min

0

Steel grade

Chemical composition %

C

Si

Mn

Cr

Mo

Ni

Nb

Ti

V

Cu

P

S

≤

10

0.07~

0.13

0.17~

0.37

0.35~

0.65

≤0.15

≤0.15

≤

0.25

-

-

≤0.08

≤0.20

0.025

0.015

20

0.17~

0.23

0.17~

0.37

0.35~

0.65

≤0.25

≤0.15

≤

0.25

-

-

≤0.08

≤0.20

0.025

0.015

12CrMo

0.08~

0.15

0.17~

0.37

0.40~

0.70

0.40~

0.70

0.40~

0.55

≤

0.30

-

-

-

≤0.20

0.025

0.015

15CrMo

0.12~

0.018

0.17~

0.37

0.40~

0.70

0.80~

1.10

0.40~

0.55

≤

0.30

-

-

-

≤0.20

0.025

0.015

12CrlMo

0.08~

0.15

0.50~

1.00

0.30~

0.60

1.00~

1.50

0.45~

0.65

≤

0.30

-

-

-

≤0.20

0.025

0.015

12CrlMoV

0.08~

0.15

0.17~

0.37

0.40~

0.70

0.90~

1.20

0.25~

0.35

≤

0.30

-

-

0.15~

0.30

≤0.20

0.025

0.015

12Cr2Mo

0.08~

0.15

≤0.50

0.40~

0.60

2.00~

2.50

0.90~

1.13

≤

0.30

-

-

-

≤0.20

0.025

0.015

12Cr5MoI

12Cr5MoNT

≤

0.15

≤0.50

0.30~

0.60

4.00~

6.00

0.45~

0.60

≤

0.60

-

-

-

≤0.20

0.025

0.015

12Cr9MoI

12Cr9MoNT

≤

0.15

0.25~

1.00

0.30~

0.60

8.00~

10.00

0.90~

1.10

≤

0.60

-

-

-

≤0.20

0.025

0.015

07Cr19Ni10

0.04~

0.10

≤

1.00

≤2.00

18.00~

20.00

-

8.00~

11.00

-

-

-

-

0.030

0.015

07Cr18Ni11Nb

0.04~

0.10

≤

1.00

≤2.00

17.00~

19.00

-

9.00~

12.00

8C~

1.10

-

-

-

0.030

0.015

07Cr19Ni11NTi

0.04~

0.10

≤0.75

≤2.00

17.00~

20.00

-

9.00~

13.00

-

4C~

0.60

-

-

0.030

0.015

022Cr17Ni12Mo2

≤

0.30

≤1.00

≤2.00

16.00~

18.00

2.00~

3.00

10.00~

14.00

-

-

-

-

0.030

0.015

Steel Grade

Heat Treatment Standard

10^a

Normalizing;At Temperature 880℃~940℃

20^a

Normalizing:At Temperature 880℃~940℃

12CrMo^b

Normalizing:At Temperature 900℃~960℃

Tempering:At Temperature 670℃~730℃

15CrMo^b

Normalizing:At Temperature 900℃~960℃

Tempering:At Temperature 680℃~730℃

12Cr1Mo^b

Normalizing:At Temperature 900℃~960℃

Tempering:At Temperature 680℃~750℃

12Cr1MoV^b

S≤30mm:Normalizing:At Temperature 980℃~1020℃

Tempering:At Temperature 720℃~760℃

S＞30mm:Quenching:At Temperature 950℃~990℃

Tempering:At Temperature 720℃~760℃

Or       Normalizing:At Temperature 980℃~1020℃

(rapid cooling after Normalizing)

Tempering:At Temperature 720℃~760℃

12Cr2Mo^b

S≤30mm:Normalizing:At Temperature 900℃~960℃

Tempering:At Temperature 700℃~750℃

S＞30mm:Quenching:At Temperature ≥ 900℃

Tempering:At Temperature 700℃~750℃

Or       Normalizing:At Temperature 900℃~960℃

(rapid cooling after Normalizing)

Tempering:At Temperature 700℃~750℃

12Cr5MoI

Full Annealing or isothermal annealing

12Cr5MoNT

Normalizing:At Temperature 930℃~980℃

Tempering:At Temperature 730℃~770℃

12Cr9MoI

Full Annealing or isothermal annealing

12Cr9MoNT

Normalizing:At Temperature 890℃~950℃

Tempering:At Temperature 720℃~800℃

07Cr19Ni10

Treatment with solid solving:At Temperature ≥ 1040℃

(rapid cooling after Treatment)

07Cr18Ni11Nb

Treatment with solid solving:

For Hot Rolled Tube At Temperature ≥ 1050℃

For Cold Drawn(rolled)Tube At Temperature ≥ 1100℃

(rapid cooling after Treatment)

07Cr19Ni11Ti

Treatment with solid solving:

For Hot Rolled Tube At Temperature ≥ 1050℃

For Cold Drawn(rolled)Tube At Temperature ≥ 1100℃

(rapid cooling after Treatment)

Steel Grade

Tensile

Strength

R_m/MPa

Lower yield strength R_p0.2/MPa

Elongation A/%

Shock absorption KV₂/J

Brinell hardness

Longitudinal direction

Transverse

Longitudinal direction

Transverse

≥

≤

10

335~475

205

25

23

40

27

-

20

410~550

245

24

22

40

27

-

12CrMo

410~560

205

21

19

40

27

156HBW

15CrMo

440~640

295

21

19

40

27

170HBW

12Cr1Mo

415~560

205

22

20

40

27

163HBW

12Cr2MoV

470~640

255

21

19

40

27

179HBW

12Cr2Mo

450~600

280

22

20

40

27

163HBW

12Cr5MoI

415~590

205

22

20

40

27

163HBW

12Cr5MoNT

480~640

280

20

18

40

27

-

12Cr9MoI

460~640

210

20

18

40

27

179HBW

12Cr9MoNT

590~740

390

18

16

40

27

-

07Cr19Ni10

≥520

205

35

-

-

187HBW

07Cr18Ni11Nb

≥520

205

35

-

-

187HBW

07Cr19Ni11Ti

≥520

205

35

-

-

187HBW

022Cr17Ni12Mo2

≥485

170

35

-

-

187HBW

If the wall thickness of the tube is less than 5mm, doesn`t have to do the hardness test

Specimen

Specimen size(heightXwidth)mm

Attenuation factor

Standard sample

10X10

1.00

Small sample

10X7.5

0.75

Small sample

10X5

0.50

Number

Testing items

Sampling quantity

1

Chemical composition

1 sample from each furnace

2

Tensile test

1 sample from each of two steel tubes on each batch

3

Hardness test

3 samples taken on 2 steel tubes on each batch

4

Impact test

All

5

Hydraulic test

1 sample from each of two steel tubes on each batch

6

Flattening test

2 samples taken on 2 steel tubes on each batch

7

Bending test

1 sample taken on 2 steel tubes on each furnace

8

Flaring test

2 samples taken on 2 steel tubes on each batch

9

Macroscopic examination

1 sample taken on 2 steel tubes on each furnace

10

Non-metallic inclusions

1 sample taken on 2 steel tubes on each furnace

11

Eddy current testing

All

12

Magnetic flux leakage detection 

All

13

Ultrasonic testing

All

14

Intergranular corrosion test

1 sample from each of two steel tubes on each batch