化学成分对Bi系易切削钢低温冲击韧性的影响  

Effect of Chemical Composition on Low Temperature Impact Toughness of Bi-series Free-cutting Steels

作　　者：王鑫[1] 李彬周 王军生 李金梦 张红梅[1] WANG Xin;LI Binzhou;WANG Junsheng;LI Jinmeng;ZHANG Hongmei(School of Material and Metallurgy, University of Science and Technology, Anshan Liaoning 114051, China;Anshan Iron & Steel Group Beijing Research Institute Co., Ltd., Beijing 102209, China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051 [2]鞍钢集团北京研究院有限公司,北京102209

出　　处：《上海金属》2021年第6期25-31,共7页Shanghai Metals

摘　　要：对5种不同成分的含Bi易切削钢进行了室温、-20和-40℃的冲击试验。利用扫描电子显微镜和能谱仪对断口形貌及断口处夹杂物进行了观察与分析,以研究化学成分对含铋钢低温冲击韧性及断口形貌的影响。结果表明:低硫Bi系易切削钢的低温冲击韧性优于高硫Bi系易切削钢,不含Bi高硫易切削钢的低温冲击韧性最差;含Te和含Sn、Sb的Bi系易切削钢的韧窝大、深浅不一,且尺寸较大的片状夹杂物较多,其低温冲击韧性显著低于含Bi低硫易切削钢;含Bi和S的质量分数分别为0.0110%和0.0008%的硫铋易切削钢的韧窝小而均匀,夹杂物基本为尺寸较小的团簇状单质Bi,数量极少,低温冲击韧性最优。Impact tests of Bi-containing free-cutting steels with five different compositions were carried out at room temperature,-20 and-40℃,respectively.The fracture morphology and the inclusions in the fracture were observed and analyzed by scanning electron microscope and energy dispersive spectrometer,to investigate the effect of chemical composition on low temperature impact toughness and fracture morphology.The results showed that(a)the low temperature impact toughness of low-sulfur Bi-series free-cutting steels was better than that of high-sulfur Bi-series free-cutting steels,and the low temperature impact toughness of high-sulfur free-cutting steels without Bi was the worst;(b)the Bi-containing free-cutting steels containing Te and containing Sn and Sb had large dimples differing in depth and large lamellar inclusions,thus was significantly lower in low temperature impact toughness than the low-sulfur Bi-containing free-cutting steel;(c)the free-cutting steel containing 0.0110%Bi or 0.0008%S by mass,exhibited small and uniform dimples,basically small and few elemental Bi clusters,and thereby the best low temperature impact toughness.

关 键 词：含Bi易切削钢 低温冲击韧性 断口形貌 夹杂物 

分 类 号：TG142.7[一般工业技术—材料科学与工程]