残余元素在CSP热轧钢板中的分布及其对力学性能的影响

利用扫描电镜和X-EDS能谱分析系统研究了残余元素As、Sn和Cu在超低碳CSP热轧钢板中的分布情况, 并且利用MTS-810拉伸试验机对残余元素含量不同的热轧钢板进行了力学性能测试。结果表明:残余元素As、Sn和Cu在实验温度低于1 050 ℃时均匀的分布在热轧钢板基体中; 实验温度高于1 050 ℃后残余元素As和Cu出现富集偏析现象, 富集偏析主要发生在氧化膜与基体交界处球形优先氧化物周围, 没有发现Sn元素发生富集偏聚; 残余元素的存在会导致热轧板表面质量恶化, 此外, 残余元素对CSP热轧钢板的力学性能有重要影响, 随着残余元素含量的增加, 抗拉强度和屈服强度明显提高, 但延伸率下降。

Distribution of Residual Elements in CSP Hot-Rolled Sheet and Their Effects on Mechanical Properties

The distribution of residual elements such as As, Sn and Cu in hot-rolled sheet produced by CSP was investigated by scanning electron microscope and X-EDS analysis system. The mechanical properties of the sheets with different contents of As, Sn and Cu were tested by MTS-810 tensile testing machine. The test result shows that the distribution of the residual elements such as As, Sn and Cu is uniform when the experimental temperature is below 1 050 ℃. When the experimental temperature is above 1 050 ℃, apparent enrichment of As and Cu occurs around the spherical oxides at the juncture of the oxidation layer and steel matrix. The enrichment of Sn is not found in this test. It is found that the residual elements have a great effect on the mechanical properties of the hot-rolled sheet produced by CSP. With the increase of the residual elements, the yield strength and tensile strength apparently increase.