TiAl合金/40Cr钢摩擦焊接头的组织与力学性能

讨论了焊后热处理对Ti Al合金与40Cr热轧钢摩擦焊接头显微组织及力学性能的影响。焊态下,钢侧界面层附近发生马氏体转变,界面层中碳原子富集生成Ti C,降低了接头的力学性能;Ti Al合金侧形成了羽毛状及魏氏体组织。经580°C和630°C保温2 h焊后热处理,界面层附近形成回火索氏体组织,碳弥散分布,接头的抗拉强度由焊态时的86 MPa分别提高至395 MPa和330 MPa。焊态下,接头沿界面层断裂;热处理后,接头呈准解理断裂,断裂位置位于Ti Al合金侧,距界面层约1 mm。...

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Published in中国有色金属学报：英文版 Vol. 24; no. 10; pp. 3126 - 3133
Main Author 董红刚 于连震 高洪明 邓德伟 周文龙 董闯
Format Journal Article
LanguageEnglish
Published 2014
Subjects
TiAl合金
异种金属焊接
摩擦焊
焊后热处理
钢
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Summary:讨论了焊后热处理对Ti Al合金与40Cr热轧钢摩擦焊接头显微组织及力学性能的影响。焊态下,钢侧界面层附近发生马氏体转变,界面层中碳原子富集生成Ti C,降低了接头的力学性能;Ti Al合金侧形成了羽毛状及魏氏体组织。经580°C和630°C保温2 h焊后热处理,界面层附近形成回火索氏体组织,碳弥散分布,接头的抗拉强度由焊态时的86 MPa分别提高至395 MPa和330 MPa。焊态下,接头沿界面层断裂;热处理后,接头呈准解理断裂,断裂位置位于Ti Al合金侧,距界面层约1 mm。
Bibliography:43-1239/TG
Hong-gang DONG,Lian-zhen YU,Hong-ming GAO,De-wei DENG,Wen-long ZHOU,Chuang DONG（1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085, China; 2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China; 3. Key Laboratory of Materials Modification of Ministry of Education, Dalian University of Technology, Dalian 116085, China）
TiAl alloy;steel;dissimilar metal joining;friction welding;post-weld heat treatment
Direct friction welding of Ti Al alloy to 40 Cr steel rods was conducted, and the microstructure and mechanical properties of the resultant joints in as-welded and post-weld heat treatment（PWHT） states were investigated. The martensitic transformation occurred and brittle Ti C phase formed near the interface due to C agglomeration, which degraded the joint strength and increased the microhardness at the interface in as-welded state. Feathery and Widmanstatten structure generated near the interface on Ti Al alloy side. After PWHT at 580 °C and 630 °C for 2 h, the sorbite formed and C dispersed at the interface, leading to the increase of the joint strength from 86 MPa in as-welded state to 395 MPa and 330 MPa, respectively. The heat-treated specimen fractured with quasi-cleavage features through the zone 1 mm away from the interface on TiA l alloy side, but the as-welded specimen failed through the interface.
ISSN:1003-6326