冷处理对粉末冶金高速钢组织和性能的影响  

Effect of cryogenic treatment on microstructure and properties of powder metallurgy high speed steel

作　　者：吕程 张祥林[2] LÜCheng;ZHANG Xiang-lin(School of Electrical and Mechanical Engineering,Wuhan Polytechnic,Wuhan 430072,China;School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]武汉职业技术学院机电工程学院,湖北武汉430072 [2]华中科技大学材料科学与工程学院,湖北武汉430074

出　　处：《材料热处理学报》2025年第2期182-189,共8页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2019YFB1704500)。

摘　　要：利用扫描电镜和透射电镜研究了冷处理对PM20粉末冶金高速钢微观组织的影响,探究了其微观组织和力学性能之间的关系。结果表明:在回火前进行冷处理,PM20钢基体中生成了纳米组织,其可以作为碳化物形核的核心,促进回火过程中超细碳化物的析出;淬火后在-196和-80℃进行深冷处理再回火,PM20钢中的碳化物体积分数从8.57%(淬火+回火)分别增加至9.13%和9.11%;冷处理细化了马氏体板条束,降低马氏体碳含量,使得PM20钢的抗压强度和洛氏硬度与仅进行淬火+回火处理相比有所降低。Effect of cryogenic treatment on microstructure of PM20 powder metallurgy high speed steel was studied using scanning electron microscopy and transmission electron microscopy,and the relationship between its microstructure and mechanical properties was explored.The results show that after cryogenic treatment before tempering,nano-structure is generated in the PM20 steel matrix,which can act as the core of carbides nucleation and promote the precipitation of ultrafine carbides during the tempering.After quenching and then that after undergoing cryogenic treatment at-196 and-80 ℃ before tempering,the volume fraction of carbides in the PM20 steel increases from 8.57%(quenching+tempering) to 9.13% and 9.11%,respectively.The cryogenic treatment refines the martensitic laths and reduces the martensitic carbon content,which makes the compressive strength and Rockwell hardness of the PM20 steel lower than that of only treated by quenching+tempering.

关 键 词：粉末冶金高速钢 冷处理 碳化物 马氏体 

分 类 号：TG142.4[一般工业技术—材料科学与工程]