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论文类型：期刊论文

发表时间：2015-09-01

发表刊物：JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

收录刊物：SCIE、EI、ISTIC、CSCD

卷号：31

期号：9

页面范围：962-968

ISSN号：1005-0302

关键字：Dissimilar metal joining; Friction welding; Titanium; Steel; Post-weld heat treatment; Intermetallic

摘要：Dissimilar metal joining of Ti-6Al-4V (TC4) titanium alloy to as-rolled 40Cr steel rods was conducted with friction welding, and the effect of post-weld heat treatment (PWHT) on the microstructure and mechanical properties of the resultant joints was investigated. The average tensile strength of the as-welded joints reached 766 MPa and failure occurred in 40Cr steel base metal. However, after PWHT at 600 degrees C for 0.5, 1, 2 and 3 h, the tensile strength of the joints decreased and fracture happened through the interface with quasi-cleavage features. The bending angle of specimens was improved from 9.6 degrees in as-welded state to 32.5 degrees after PWHT for 2 h. The tensile strength of the joint was enhanced by martensitic transformation near the interface in as-welded state. Sorbite formed near the interface in PWHT state and improved the bending ductility of the joint. TiC brittle phase formed at the interface after PWHT for 0.5 h and deteriorated the tensile strength and bending ductility of the joint. After PWHT for 2 h, no TiC phase was detected at the interface. The microhardness on the interface in as-welded state was higher than that after PWHT, indicating that the decrease of microhardness around the interface could be accompanied by degradation of tensile strength but improvement of bending ductility of the joints. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.