球化退火的目的是要使钢获得小颗粒球粒状碳化物能均匀地分布在铁素体基体上的显微组织。它一般用于共析、过共析和莱氏体钢。各种碳素工具钢、合金工具钢和滚动轴承钢等部要进行球化处理,以改善钢的切削性能,并为最终热处理作组织准备。亚共析钢、尤其是低碳钢的球化处理,因为含碳量低,所以较难得到理想的球化组织。另外,还由于亚共析钢具有较大的塑性,可以满足一般冷成形加工的要求。因此,对于亚共析钢球化的研究和应用,在过去未受重视。随着冷成形工艺的迅速发展,特别是冷挤、冷拉、冷冲、冷镦和冷弯成形的大量使用,对材料塑性及组 The purpose of the spheroidizing annealing is to make the steel obtain microstructure in which the small-granular spheroidal carbide can be uniformly distributed on the ferrite matrix. It is commonly used for eutectoid, eutectoid and ledeburitic steels. All kinds of carbon tool steel, alloy tool steel and rolling bearing steel and other ministries to carry out the ball to improve the cutting performance of steel, and for the final heat treatment for the organization. The hypo-eutectoid steel, especially the spheroidization of mild steel, is less able to obtain ideal spheroidized structures because of its low carbon content. In addition, but also because of the sub-eutectoid steel with greater plasticity, to meet the general cold forming requirements. Therefore, the researches and applications of sub-eutectoid steel balling have not been taken seriously in the past. With the rapid development of cold forming process, especially cold extrusion, cold drawing, cold drawing, cold heading and cold forming a large number of use, plasticity and material group