电子束束流对电子束选区熔化成形 H13钢组织和性能的影响-中国材料进展

文章信息/Info

Title:: Effect of Electron Beam Current on Microstructure and Properties of H13 Steel Fabricated by Selective Electron Beam Melting

作者:: 刘世锋1; 宋玺1; 王岩1; 薛彤1; 王建2; 石英2; （1.西安建筑科技大学冶金工程学院，陕西西安 710055）（2.西北有色金属研究院金属多孔材料国家重点实验室，陕西西安 710016）

Author(s):: LIU Shifeng1; SONG Xi1; WANG Yan1; XUE Tong1; WANG Jian2; SHI Ying2; (1. School of Metallurgical and Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China) （2. State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China)

Keywords:: H13 steel; selective electron beam melting; electron beam current; microstructure; martensite

摘要:: H13钢是使用最广泛和最具代表性的热作模具钢。采用电子束选区熔化（SEBM）技术成形H13钢能够有效解决其组织均匀度不理想的问题，而且可使其具有相当可观的力学性能表现。通过改变SEBM技术的电子束束流制备H13模具钢，并采用电子密度计、X射线衍射仪（XRD）、扫描电子显微镜（SEM）和显微维氏硬度计表征了成形件的致密度、微观组织和硬度，探究了电子束束流对成形件微观组织演变和力学性能的影响。结果表明，不同电子束束流成形的H13钢主要存在弥散的纳米尺寸微孔、局部的微米尺寸微孔以及熔合不良区域；微观组织主要为马氏体、残余奥氏体及碳化物；随着电子束束流的增加，马氏体会发生晶格畸变，基体强度增加，继续提高电子束束流，马氏体逐渐粗化，基体发生回复与再结晶，同时弥散析出二次碳化物，基体强度趋于稳定。

Abstract:: H13 steel is the most widely used and representative hot-working tool steel. The use of selective electron beam melting (SEBM) technology to form H13 steel can effectively solve the problem of unsatisfactory tissue uniformity, and it has considerable mechanical properties. In this paper, H13 steel was prepared by changing the electron beam current of SEBM technology, and the densities, microstructures and hardness of the formed parts were characterized by electron densitometry, X’ray diffractometer (XRD), scanning electron microscope (SEM) and micro-Vickers hardness tester. The effects of the electron beam current on the microstructure evolution and mechanical properties were investigated. The results show that the H13 steel formed by different electron beam current mainly has dispersed nano-sized micropores, local micro-sized micropores and poor fusion areas. The microstructure is mainly composed of martensite, residual austenite and carbide. With the increase of the electron beam current, the martensite will undergo lattice distortion and the matrix strength will increase. And if the electron beam current continues to be increased, the martensite will gradually dissolve, the matrix will recovery and recrystallization, while secondary carbide will be diffusely precipitated and the matrix strength will stabilize.