半固态变形对M2高速钢组织中碳化物的影响  

Effect of Semi-solid Deformation on Carbides in M2 High-Speed Steel

作　　者：刘成宇 LIU Cheng-yu(School of Materials Science&Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学材料科学与工程学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2019年第2期192-196,223,共6页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51504163)

摘　　要：基于半固态成型技术,采用一种新型工艺消除M2高速工具钢中大块的有害碳化物.为验证该工艺的可行性,通过控制变形温度(固液比)、变形方式等实验参数,利用金相显微镜和电子显微镜研究不同碳化物的形貌和分布,采用电子探针表征不同碳化物中元素分布,探讨新型工艺对合金凝固行为和组织中有害碳化物的影响.研究证明,在较高液相分数下变形,M2高速钢中大块的有害碳化物面积分数减小,有助于改善合金凝固组织;特别是两道次变形工艺中,分别在1 345℃和1 100℃变形25%和30%,样品中碳化物面积分数大幅降低,由铸态的14.3%降低至6.5%.Based on semi-solid forming technology,an advanced process was applied to the elimination of harmful carbide chunks in M2 high-speed tool steel.To verify the feasibility of the process,on the conditions of different deformation temperatures regarding to solid-liquid fraction and different deformation modes,the morphology and distribution of different types of carbides were studied by optical and electron microscopes,the distribution of different elements in carbides was characterized by EPMA,and the effects of the new process on solidification structure and harmful carbides were analyzed.The results show that the area fraction of the harmful carbides in the M2 high speed steel decreases when the sample deformes with the higher liquid fraction,which helps to improve the solidification structure of the alloy.Especially,when the process of two pass deformation at 1345 and 1100℃ of 25% and 30% respectively is used,the carbide volume fraction in the sample can be reduced to 6.5% from 14.3% as-cast.

关 键 词：M2高速工具钢 半固态成型 凝固 碳化物 变形方式 

分 类 号：TG142.1[一般工业技术—材料科学与工程]