硫系易切削钢C1118的工艺实践及其组织性能

通过合理的化学成分以及冶炼、连铸和轧制工艺的设计与控制,开发了一种硫系易切削钢C1118,并进行了工艺实践,成功生产了28mm的圆钢。通过金相显微镜、扫描电镜、能谱仪和Leica图像仪对其组织、夹杂物进行了观察分析,结果表明:该工艺下生产的易切削圆钢疏松等级良好,基体组织为铁素体和少量的珠光体,MnS以长条状或纺锤状存在,可以细化铁素体组织并改善钢的切削性能。开发的易切削钢C1118的力学性能满足供货要求,切削性能优异,磨损速度明显低于45号钢,相对于45号钢的加工性Kr为1.62。

Process practice,microstructure and properties of sulfur free-cutting steel C1118

Sulfur free- cutting steel C1118 was developed through reasonable designs and controls of chemical composition, smelting, continuous casting and rolling processes. Process practice was conducted which successfully produced ??28 mm round steel. Its microstructures and inclusions were observed and analyzed by means of metallographic microscope(OM), scanning electron microscope(SEM), energy disperse spectroscopy(EDS) and Leica metallographic image instrument. The results show that unconsolidated degree of this free- cutting round steel produced under this process is satisfactory. Its metallographic structure is ferrite with a little of pearlite. MnS is like long strip or spindle which could refine ferrite grains and improve the cutting performance of the steel. Mechanical properties of free- cutting steel C1118 meet the supply requirements and the steel has excellent cutting performance. Its wearing speed is significantly lower than that of steel 45, and its relative machinability Kr (comparing with steel 45) is 1.62.