Steel Grade

Chemical Composition

Mechanical property

C

Mn

Si

S

P

Cr

Ni

Cu

V

Nb

Ti

Yield point

Tensile strength

Elongation

Q195

0.06~0.12

0.25~0.50

≤0.30

≤0.050

≤0.045

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195

315~430

33

Q235

0.12~0.20

0.30~0.70

≤0.30

≤0.045

≤0.045

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235

375~500

26

Q345

≤0.20

1.00~1.60

≤0.55

≤0.40

≤0.040

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___

0.02~0.15

0.015~0.060

0.02~0.20

345

470~630

21

10#

0.07~0.13

0.35~0.65

0.17~0.37

≤0.035

≤0.035

≤0.15

≤0.30

≤0.25

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205

335

31

20#

0.17~0.23

0.35~0.65

0.17~0.37

≤0.035

≤0.035

≤0.25

≤0.30

≤0.25

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245

410

25