中文摘要：

研究了喷射成形高速钢SFT15热处理前后的微观组织。结果表明,喷射成形制备的SFT15高速钢晶粒细小,无宏观偏析,组织致密,沉积坯平均体密度为8.208g/cm3,达到理论密度的99.8%。SFT15在热处理前的沉积坯硬度为56.5HRC,经热等静压和热处理后进一步提高到67HRC,冲击韧度达到11.8 J/cm2。采用SEM和TEM研究了SFT15的内部组织发现,热处理后SFT15高速钢组织主要为回火马氏体和碳化物。内部绝大部分为小于20μm的等轴晶,晶界和晶内分布许多M6C型的碳化物。

英文摘要：

The microstructure before and after heat treatment of high speed steel（HSS） T15 prepared by spray forming was researched.The result indicated that the high-quality billet of HSS T15 exhibited high-density,much fine grains than that of common HSS and segregation-free macrostructure.The average density of billet before heat treatment（HT） is 8.208g/cm3 which is 99.8% of theoretical density.The hardness of SFT15 billet was HRC56.5,after HIP and HT it was improved to HRC67,and fracture toughness was 11.8J/cm2.By means of Scanning Electron Microscopy（SEM） and transmission Electron Microscopy（TEM）,we found that the structure of HSS SFT15 after heat treatment is constituted by tempered martensite and carbide.And most grain is less than 20μm.Much carbide whose structure is M6C is distributed in grains and grain boundary.