标准 牌号 化学成分(%) CEV(%) C Si Mn P S V Nb Ti API SPEC 5L GB/T9711.2 B ≤0.16 ≤0.40 ≤1.10 ≤0.020 ≤0.010 - - - ≤0.42 X42 ≤0.17 ≤0.40 ≤1.20 ≤0.020 ≤0.010 ≤0.05 ≤0.05 ≤0.04 ≤0.42 X52 ≤0.20 ≤0.45 ≤1.60 ≤0.020 ≤0.010 ≤0.10 ≤0.05 ≤0.04 ≤0.45 X60 ≤0.21 ≤0.45 ≤1.60 ≤0.020 ≤0.010 ≤0.15 ≤0.05 ≤0.04 协议 X65 ≤0.16 ≤0.45 ≤1.60 ≤0.020 ≤0.010 ≤0.06 ≤0.05 ≤0.06 ≤0.45 X70 ≤0.16 ≤0.45 ≤1.70 ≤0.020 ≤0.010 ≤0.06 ≤0.05 ≤0.06 ≤0.45 http://www.tjdgggc.com/