扫描电子束表面改性对40Cr钢组织和性能的影响  

Effects of Electron Beam Surface Modification on Microstructure and Properties of 40Cr Steel

作　　者：王荣[1] 龚玉辉 吴辉 魏德强[1] WANG Rong;GONG Yuhui;WU Hui;WEI Deqiang(College of Mechanical and Electronic Engineering,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学机电工程学院,广西桂林541004

出　　处：《热加工工艺》2022年第20期109-113,117,共6页Hot Working Technology

基　　金：国家自然科学基金项目(51665009);广西区自然科学基金项目(2017GXNSFDA198007)。

摘　　要：电子束是一种新型载能束表面改性技术,可改善材料表面的组织和性能。采用连续扫描电子束方式对40Cr钢表面进行改性处理,研究不同电子束束流对40Cr钢表面显微组织及力学性能的影响规律。结果表明:经扫描电子束表面改性处理,试样横截面形貌可分为熔融层、热影响区和基体3个区域。熔融层和热影响区组织主要由针状马氏体和板条马氏体组成,晶粒细小均匀。束流为4 mA,试样表面粗糙度由2.306μm降到1.469μm,表面粗糙度随着束流的增加先减小后增大;当束流为6 mA时,表面显微硬度高达756.5 HV,是基体硬度的2.44倍。随束流的增大,表面显微硬度呈非线性增加。Electron beam is a new surface modification technology of energy-carrying beam,which can effectively improve the surface structure and properties of materials.The surface modification of 40Cr steel was carried out by continuous scanning electron beam,and the effects of different electron beam currents on the surface microstructure and mechanical properties of 40Cr steel were studied.The results show that the cross-section morphology of the sample can be divided into three areas:the molten layer,the heat-affected zone and the matrix after the surface modification of the scanning electron beam.The microstructure of the melt layer and heat-affected zone is mainly composed of acicular martensite and lath martensite with fine and uniform grain size.When the beam is 4 mA,the surface roughness of the sample decreases from 2.306μm to 1.469μm,and the surface roughness decreases first and then increases with the increase of the beam.When the beam is 6 mA,the surface microhardness is up to 756.5 HV,which is 2.44 times of the matrix hardness.With the increase of the beam,the surface microhardness increases nonlinearly.

关 键 词：扫描电子束 40Cr 显微组织 表面改性 力学性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]