Abstract: Analysis of phase composition, particle size and hardness of metallographic structure and sulfide inclusions in 1215MS free cutting steel Φ12 mm coil are carried out by means of optical microscope, scanning electron microscope with energy dispersive spectrometer, microhardness tester and thermdynamic software Thermo-Calc. The results show that, the proportion of ferrite in 1215MS steel is 93% -96% ,and the proportion of pearlite is 4% ~5% ; the average equivalent diameter of ferrite is 22.30 μm,the average diameter of pearlite is 16. 83 p.m, sulfide is evenly distributed in the edge of grain boundary and the ferrite,the equivalent diameter of sulfide is 5.077μm, the average Vickers hardness of MnS, ferrite, and pearlite is 80 HV10,100 HV10,175 HV10,respectively.

摘要： 采用光学显微镜、扫描电镜及能谱、显微硬度测量仪以及热力学软件Thermo-Calc对1215MS易切削钢Φ12 mm盘条金相组织及硫化物夹杂进行了相组成及粒径与硬度解析。结果表明:1215MS钢中铁素体所占比例93%～96%,珠光体比例4%～5%;铁素体平均等效直径为22.30μm,珠光体的平均直径为16.83μm,硫化物均匀分布在晶界的边缘和铁素体中,硫化物的当量直径为5.077μm;MnS的平均维氏硬度值为80 HV10,铁素体硬度值为100 HV10,珠光体硬度值为175 HV10。