喷射成形M4高速钢的高温热变形及组织演变  

High-temperature Thermal Deformation and Microstructure Evolution of Spray Formed M4 High Speed Steel

作　　者：王和斌[1] 张金祥[1] 卢林[1] 侯陇刚[1] 崔华[1] 黄进峰[1] 张济山[1] 

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《材料研究学报》2013年第2期167-172,共6页Chinese Journal of Materials Research

基　　金：国家重点基础研究发展计划2011CB606303资助项目~~

摘　　要：使用热模拟试验机在变形温度为950℃—1150℃,变形速率为0.01s-1—10s-1、总应变为0.7的条件下对喷射成形M4高速钢进行热压缩变形,建立了热变形本构方程并计算了热变形激活能。同时,对不同状态沉积态合金的组织进行了表征。结果表明,沉积态M4高速钢晶粒细小、均匀,无宏观偏析;热变形时表现出显著的动态再结晶特征,且变形温度和应变速率对合金流变应力影响显著;变形温度对碳化物的形貌和分布也有较大的影响。The hot compression deformation behavior of the spray-formed M4 high speed steel was investigated on thermal simulator at the temperature of 950 ℃-1150 ℃, strain rate of 0.01 s^-1-10 s^-1 and to- tal strain of 0.7. The hot deformation constitutive equation for this alloy was obtained as well as the hot deformation activation energy. And the microstructures of the as-deposited alloy at different states were characterized presently. It is shown that the microstructure of the as-deposited M4 high speed steel possesses much finer and uniform-distributed grains without macrosegregation than the as-cast M4 high speed steel. The dynamic recrystallization are prominently performed during the deformation and the flow stresses are greatly affected by the temperature and strain rate. The morphology and distribution of the carbides are obviouslv influenced bv the deformation temDerature.

关 键 词：金属材料 喷射成形 组织 热变形 高速钢 

分 类 号：TG142[一般工业技术—材料科学与工程]