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现场选取3批次试生产的DC04钢板,用拉伸试验机测试其力学性能,用金相显微镜、扫描电镜、能谱和透射电镜观察分析了3批钢板中的显微组织、析出物及第二相粒子情况。结果表明,第2批次试验钢板的屈服强度均值<190 MPa,抗拉强度均值>310 MPa,r90达2.5,板材深冲性能良好;而1、3批次分别出现r值偏低、强度偏高的现象。试样基体组织虽然较为均匀,但仍存在等轴晶粒与“饼形”晶粒的差别。扫描电镜下发现3批次试验钢中的特有析出物,但1、3批次试验钢中存在更多不利板料性能的硅酸盐及钙铝酸盐夹杂,透射电镜随机视场中发现有利第二相粒子Al N,是第2批次试验钢形成“饼形”晶粒,是有利于提高深冲性能的原因。
Three batches of DC04 steel plates were selected on the spot and their mechanical properties were tested with a tensile testing machine. The microstructure, precipitates and the contents of the three batches of steel plates were observed by optical microscope, scanning electron microscope, energy dispersive spectroscopy and transmission electron microscope. Two-phase particle situation. The results showed that the mean value of yield strength of the second batch of test plate was <190 MPa, the average value of tensile strength was 310 MPa, r90 was 2.5, and the deep drawing performance of the plate was good. High phenomenon. Although the microstructure of the sample matrix is more uniform, there is still the difference between the equiaxed grains and the “pie-shaped” grains. Scanning electron microscopy found three batches of test steel in the unique precipitates, but 1,3 batches of test steel there are more unfavorable sheet properties of silicate and calcium aluminate inclusions, transmission electron microscopy random field of view found to be beneficial The second phase Al N, which is the second batch of test steel to form “cake-shaped” grains, is conducive to improving the deep-drawing properties.