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论文类型：期刊论文

发表时间：2017-07-15

发表刊物：NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

收录刊物：SCIE、EI、Scopus

卷号：403

页面范围：45-50

ISSN号：0168-583X

关键字：High current pulsed electron beam; 40CrNiMo7 steel; Surface nanocrystallization; Microstructure; Microhardness

摘要：In this paper, surface modification of 40CrNiMo7 steel was investigated with high current pulsed electron beam (HCPEB) treatment. The scanning electron microscope (SEM), electron back-scattered diffraction (EBSD), electron probe micro analysis (EPMA), transmission electron microscopy (TEM) and X-ray diffraction (XRD) results show that a composite microstructure of mainly refined austenite and a little marten site was produced in the surface modified layer of depth similar to 7 mu m. The average size of small cells on modified surface was decreased to similar to 120 nm after 25 HCPEB pulses. XRD analysis indicates a preferred orientation of austenite (220) crystal plane, and TEM results show the broken and dissolved cementite in the surface modified layer. After HCPEB treatment, all the samples exhibited a remarkable improvement in surface microhardness measurement, up to similar to 1000 HK for 15 HCPEB pulses, as tripled of the initial 40CrNiMo7 steel. (C) 2017 Elsevier B.V. All rights reserved.