牌号质量等级化学成分(质量分数)/%CSiMnPSVbNBbTibALsaCrCuNiMo

≤

≤

≥

牌号Q235GJB、C0.200.350.60-1.500.0250.015---0.0150.300.300.300.08

D、E0.180.0250.010

Q345GJB、C0.200.55≤1.600.0250.0150.1500.0700.0350.0150.300.300.300.20

D、E0.180.0200.010

Q390GJB、C0.200.55≤1.700.0250.0150.2000.0700.0300.0150.300.300.700.50

D、E0.180.0200.010

Q420GJB、C0.200.55≤1.700.0250.0150.2000.0700.0300.0150.800.301.000.50

D、E0.180.0200.010

Q460GJB、C0.200.55≤1.700.0250.0150.2000.1100.0300.0151.200.501.200.50

D、E0.180.0200.010

Q500GJC0.180.60≤1.800.0250.0150.1200.1100.0300.0151.200.501.200.60

D、E0.0200.010

Q550GJCC0.180.60≤2.000.0250.0150.1200.1100.0300.0151.200.502.000.60

D、E0.0200.010

Q620GJCC0.180.60≤2.000.0250.0150.1200.1100.0300.0151.200.502.000.60

D、E0.0200.010

Q690GJCC0.180.60

≤2.200.0250.0150.1200.1100.0300.0151.200.502.000.60

D、E0.0200.010

a 允许用全铝含量(Alt)来代替酸溶铝含量(Als)的要求，此时全铝含量Alt应不小于0.020％，如果钢中添加V、Nb或Ti任一种元素，且其含量不低于0.015％时，小铝含量不适用。

b 当V、Nb、Ti组合加入时，对于Q235GJ、Q345GJ，(V+Nb+Ti)≤0.15％,对于Q390GJ、Q420GJ、Q460GJ,(V+Nb+Ti)≤0.22％。

c 当添加硼时，Q550GJ、Q620GJ、Q690GJ及淬火加回火状态钢中的B≤0.003％。