q235B化学成分 含硅量接近0.30好还是小于0.30好!

Q235分A、B、C、D四级(GB700-88)
Q235A级含C0.14~0.22% Mn0.30~0.65Si≤0.30S≤0.050P≤0.045
Q235B级含C0.12~0.20% Mn0.30~0.670Si≤0.30S≤0.045P≤0.045
Q235C级含C≤0.18% Mn0.35~0.80Si≤0.30S≤0.040P≤0.040
Q235D级含C≤0.17% Mn0.35~0.80Si≤0.35S≤0.040P≤0.035