贝氏体型非调质钢连铸圆坏组织和力学性能研究

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文章编号：2096-2983（2025）03-0035-07

关键词：热处理；贝氏体型非调质钢连铸圆坯；取样位置；板条贝氏体；粒状贝氏体中图分类号：TQ153.1 文献标志码：A

Abstract： Using equipment such as metallographic microscope， scanning electron microscope， X-ray diffractometer，Rockwell hardness tester，and electronic universal material testing machine， the effects of 450∘C tempering on the microstructure and mechanical properties of a bainitic type non-quenched and tempered steel continuous casting round bilet at different positions were studied. The diameter of the bainitic non-quenched and tempered steel continuous casting round billet was 230mm ，and the samples were cut along the radius from the center to the edge at equal distances.The results of microstructure observation show that as the sampling position is closer to the edge of the bainitic type non-quenched and tempered steel continuous casting round bilet， the size of austenite grains and the size of martensite islands （martensite/austenite islands）are smaller，the number of martensite islands is greater，the volume fraction of lath bainite is larger，the length and width of the lath are smaller，and the volume fraction of granular bainite is smaller.The test results of mechanical properties show that as the sampling position is closer to the edge of the bainitic type non-quenched and tempered steel continuous casting，the Rockwell hardness，tensile strength， yield strength and elongation are all larger of the bainitic type non-quenched and tempered steel continuous casting round billet. The mechanical properties at the edge are the best.

Keywords： heat treatment; bainitic type non-quenched and tempered steel continuous casting round billet; sampling location； lath bainite； granular bainite

贝氏体型非调质钢（记为B钢）具有良好的强度和韧性，其含碳量一般较少[1]，显微组织基本为贝氏体，有少量铁素体和珠光体，抗拉强度可达800～1000MPa ，甚至更高[2。（剩余6016字）