锰对热轧态双相钢显微组织和力学性能的影响

Influence of Manganese on the Microstructure and Mechanical Properties of As-Hot-Rolled Dual-Phase Steels

用薄晶体透射电镜研究锰对热轧空冷后低碳Si—Mn双相钢的组织和力学性能的影响。实验结果表明:钢中锰含量为1.79％时,显微组织中出现珠光体。拉伸工程应力—应变曲线有明显物理屈服延伸。钢中锰含量越少、珠光体量越多时,应力—应变曲线上屈服平台越长。锰含量大于2.09％时,轧态组织中不再出现非马氏体型转变产物珠光体。轧态组织中的马氏体岛区,由几个微区组成。这些微区分别为内孪晶马氏体区和位错板条马氏体区。

When the manganese content in steel is 1. 79% , the as-hot-rolled microstructure consists some pearlite, and there is physical yield plateau in the stress-strain curve. The lower manganese content, the more amount of pearlite, and the longer plateau of physical yield. But when the manganese content is more than 2. 09 %, there is no product of non-martensitic transformation. In the microstructure of as-hot-rolled steel, the island field of martensite is composed of several parts. They are dislocated lath martensite area and twinned martensite area respectively.