A.特殊性能刚 B.合金工具钢 C.合金容器刚 D.合金结构钢
A.碳钢 B.低碳钢 C.中碳钢 D.高碳钢
A.低碳钢含碳量小于0.25% B.中碳钢含碳量小于等于0.60% C.高碳钢含碳量大于0.60% D.优质高碳钢含碳量大于0.60%