斜坡预结晶M2高速钢半固态坯料的组织和热塑性研究  

Study on Microstructure and Hot Plasticity of Semisolid M2 High Speed Steel Billet by Cooling Slope

作　　者：勾军年[1] 邢书明[1] 张密兰[1] 和优峰[1] 

机构地区：[1]北京交通大学半固态成型中心

出　　处：《特种铸造及有色合金》2007年第S1期425-428,共4页Special Casting & Nonferrous Alloys

基　　金：北京交通大学"十五"重大科研基金项目(230-12)

摘　　要：采用斜坡预结晶法制备出M2高速钢半固态铸坯,并对其微观组织和热塑性进行了研究。半固态加工技术解决了M2高速钢铸态坯料中碳化物偏析严重的问题,改善了铸态微观组织和热塑性加工性能。使其晶粒由发达的树枝晶变为细小圆整的等轴晶,共晶碳化物明显比常规铸态中的薄而少,并且其共晶碳化物不同于常规铸态组织中那样发达的网状组织,碳化物网的连续度也大大降低;因此这也提高了它的热塑性,且锻后半固态坯料的碳化物不均匀度低于常规铸态;然而其在单向应力下的最佳热塑性温度范围没有改变,仍然是900~1200℃。The semisolid M2 HSS ingots were prepared by cool-body method,and the microstructure and hot plasticity of casting M2 HSS were investigated.The semisolid processing technology resolves the serious problem of carbides segregation in casting structure.The grains are fine-round-equiaxed grains but not dendrites as they were,and the eutectic carbides turn into thin and broken network from coarse network structure.As a result,the hot plasticity is improved,and the carbide distribution of the semisolid M2 is better than conventional casting ingots after being forged.However the best hot plastic temperature interval isn't changed under the condition of uniaxial stress,which is from 900 ℃ to 1 200 ℃.

关 键 词：M2高速钢 半固态 共晶碳化物 热塑性 

分 类 号：TG249.9[金属学及工艺—铸造]