astma573gr70化学成分：C ≤0.27-0.28Mn 0.85-1.20P ≤0.035S ≤0.004Si 0.15-0.40力学性能：抗拉强度Mpa 485-620屈服强度Mpa 290伸长率最小，%,A 18执行标准：ASTM A573/573M
