低碳高硫含锡锑复合易切削钢

Compound low carbon and high sulfur free-cutting steel with Sn and Sb

对复合添加少量Sn和Sb或Sn和Bi的低碳高硫易切削钢做了切削和高温热塑性实验.结果表明:试样在长时间的高速切削条件下刀具后刀面磨损很小,其易切削性能明显优于SAE1215钢.含Sn和Sb的钢样在750～950℃温度范围内塑性较差,在1050～1300℃范围内具有良好的塑性.扫描电镜及能谱分析表明:钢中Sn和Sb元素在晶界、MnS夹杂物内及MnS边界处均存在;大部分的Bi元素附着在MnS夹杂物上,一部分弥散分布在钢的基体中;钢中MnS夹杂主要呈球状和纺锤状.

Cutting tests and high-temperature thermo-ductility experiment were carried out on low-carbon and high-sulfur freecutting steel with low contents of tin and antimony or bismuth. The results show that the wear at the tool flank face for machining of experimental steel is very small after long-time and high-speed machining tests. The machinability of the new steel is significantly bet- ter than that of SAE1215. The thermo-ductility of the steel with Sn and Sb is poor within the range from 750 to 950 ℃ but good from 1050 to 1300℃. It is also showed by SEM and EDS that tin and antimony exist at grain boundaries in the steel, and in or around MnS inclusions. Most of bismuth element are attached to MnS inclusions, some are scattered in the steel matrix. The shapes of MnS inclusions are mainly spherical and spindle.