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Indexed by:期刊论文

Date of Publication:2016-02-01

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

Included Journals:SCIE、EI

Volume:368

Page Number:81-85

ISSN No.:0168-583X

Key Words:High current pulsed electron beam; 40CrNiMo7 steel; Microstructure; Microhardness; Wear

Abstract:High current pulsed electron beam (HCPEB) treatment was conducted on 40CrNiMo7 steel with accelerating voltage 27 kV, energy density 3 J/cm(2), pulse duration 2.5 mu s and 1-50 pulses. The evolutions of surface microstructure were investigated by using optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) techniques. It was found that the carbides in the surface remelted layer of depth similar to 4 mu m were dissolved gradually along with the increasing number of HCPEB pulses. Eventually, the surface microstructure of 40CrNiMo7 steel was transformed to a complex structure composed of very refined similar to 150 nm austenite as the main part and a little quantity of martensite phases. After 15 pulses of HCPEB treatment, the surface microhardness was doubled to 553 HV, and the wear rate decreased to one third of the initial state correspondingly. (C) 2015 Elsevier B.V. All rights reserved.