60Si_2Mn半固态非枝晶组织特征与触变性能

Thixotropic Behavior and Microstructures of Semisolid 60Si_2Mn Spring Steel

利用自制高熔点半固态试样制备装置,对60Si2Mn半固态试样非枝晶组织以及影响因素进行了试验研究.结果表明:60Si2Mn半固态显微组织结构的特点为近球形先析出相均匀分布于残余液相.搅拌工艺制度、搅拌功率与搅拌时间对凝固初生相形态影响显著.采取降温搅拌方式,较大搅拌功率和搅拌时间,初生组织得到了充分的细化和均匀的球化.60Si2Mn非枝晶组织形态是影响剪切变稀触变性能的主要因素.

The microstructure developing of 60Si2Mn semisolid slurry was investigated experimentally with self-made high melting point semisolid apparatus. The results show that the as-received microstructure of semisolid samples presents globular crystals evenly distributed in the liquid phase. Stirring way and stirring power and time have evident effect on the solidifying pattern of the primary phase. The as-received prior microstructure which is stirred in the isothermal way evolve fully finer and rounder with the increase of stirring power and time. The morphology of 60Si2Mn semisolid samples is major factors that affect the shear thinning behavior.