Standard

Grade

Tensile Strength

（MPa）

Yield Strength

（MPa）

Y.S/T.S

Elongation

（%）

0℃Akv（J）

Heat Treatment

API SPEC 5L GB/T9711

L245/B

≥415

245～440

≤0.80

22

≥40

Normalizing

API SPEC 5L GB/T9711

L290/X42

≥415

290～440

≤0.80

21

≥40

Normalizing

API SPEC 5L GB/T9711

L360/X52

≥460

360～510

≤0.85

20

≥40

Normalizing

API SPEC 5L GB/T9711

L415/X60

≥520

415～565

≤0.85

18

≥40

Normalizing

API SPEC 5L GB/T9711

L450/X65

≥535

450～570

≤0.90

18

≥40

Quenching+Tempering

API SPEC 5L GB/T9711

L485/X70

≥570

485～605

≤0.90

18

≥40

Quenching+Tempering

Product Level

Steel grade

Chemical composition, %

C

Mn

P

S

Si

V

Nb

Ti

CEpcm

PSL 1

B or L245

≤0.28

≤1.20

≤0.030

≤0.030

-

-

-

-

-

x42 or L290

≤0.28

≤1.30

≤0.030

≤0.030

-

-

-

-

-

X46 or L320

≤0.28

≤1.40

≤0.030

≤0.030

-

-

-

-

-

X52 or L360

≤0.28

≤1.40

≤0.030

≤0.030

-

-

-

-

-

X56 or L390

≤0.28

≤1.40

≤0.030

≤0.030

-

-

-

-

-

X60 or L415

≤0.28

≤1.40

≤0.030

≤0.030

-

-

-

-

-

X70

≤0.28

≤1.40

≤0.030

≤0.030

-

-

-

-

-

PSL 2

BR or L245R

≤0.24

≤1.20

≤0.025

≤0.015

≤0.40

c

c

≤0.04

≤0.25

X42R or L290R

≤0.24

≤1.20

≤0.025

≤0.015

≤0.40

≤0.06

≤0.05

≤0.04

≤0.25

BN or L245N

≤0.24

≤1.20

≤0.025

≤0.015

≤0.40

c

c

≤0.04

≤0.25

X42N or L290N

≤0.24

≤1.30

≤0.025

≤0.015

≤0.40

≤0.06

≤0.05

≤0.04

≤0.25

X46N or L320N

≤0.24

≤1.40

≤0.025

≤0.015

≤0.40

≤0.07

≤0.05

≤0.04

≤0.25

X52N or L360N

≤0.24

≤1.40

≤0.025

≤0.015

≤0.45

≤0.10

≤0.05

≤0.04

≤0.25

X56N or L390N

≤0.24

≤1.40

≤0.025

≤0.015

≤0.45

≤0.10

≤0.05

≤0.04

≤0.25

X60N or L415N

≤0.24

≤1.40

≤0.025

≤0.015

≤0.45

≤0.10

≤0.05

≤0.04

-

X65N or L450N

≤0.24

≤1.40

≤0.025

≤0.015

≤0.45

≤0.10

≤0.05

≤0.04

-

X70N

≤0.24

≤1.40

≤0.025

≤0.015

≤0.45

≤0.10

≤0.05

≤0.04

-

X80

≤0.24

≤1.40

≤0.025

≤0.015

≤0.45

≤0.10

≤0.05

≤0.04