C

Si

Mn

P

S

Al

Cr

Cu

Ti

N

O

0.07~0.09

0.40~0.50

0.60~0.75

≤0.010

≤0.002

0.030~0.045

0.55~0.70

0.25~0.045

0.07~0.085

≤0.0060

≤0.0040