电致奥氏体增韧高强钢焊接热影响区机理  

Mechanism of electropulsing-induced austenite toughening for welding heat-affected zone of high strength steel

作　　者：陈章兰 熊云峰[1] 李晓文 王九龙 Chen Zhanglan;Xiong Yunfeng;Li Xiaowen;Wang Jiulong(Jimei University,Xiamen 361016,Fujian,China;Jinhan Electromechanical Equipment Co.,Ltd.of Xiamen,Xiamen 361021,Fujian,China)

机构地区：[1]集美大学,福建厦门361001 [2]厦门精悍机电设备有限公司,福建厦门361021

出　　处：《焊接》2022年第3期13-18,共6页Welding & Joining

基　　金：国家自然科学基金资助项目(51909106);福建省自然科学基金资助项目(2020J01684,2021J01842);厦门市科研补助项目(3502Z20203053).

摘　　要：采用电脉冲处理FH690钢焊接热影响区,利用显微观察和和力学性能试验,分析了电脉冲效应对热影响区韧性的影响。缺口冲击试验结果表明电脉冲处理后热影响区的韧性增强,显微观察断口形貌呈塑性,电子背射衍射试验表明塑性相为奥氏体。在电脉冲作用下,脆性组元的大电阻产生集中的焦耳热和电流密度,依据Boltzmann分布规律,揭示了薄膜状奥氏体在电压梯度、温度梯度及其产生的压应力梯度综合作用下的形成机理。电脉冲作用斑点不超过0.2 mm,与经典焊后热处理韧化技术相比,显示了电脉冲韧化的局域性特征。Electropulsing treatment was used to treat welding heat-affected zone of FH690 steel,and effect of electropulsing on toughness of heat-affected zone was analyzed by microscopic observation and mechanical properties test.The results of notch impact test showed that toughness of heat affected zone was enhanced after electropulsing treatment,fracture morphology was plastic under microscopic observation,and the plastic phase was austenite by electron back scattered diffraction test.Under the action of electropulsing,the large resistance of brittle element produced concentrated joule heat and current density.According to the Boltzmann distribution law,the formation mechanism of thin-film austenite was revealed under the comprehensive action of voltage gradient,temperature gradient and the generated compressive stress gradient.The spot affected by electropulsing was not more than 0.2 mm,compared with the classical post-weld heat treatment toughening technology,it showed the local characteristics of electric pulse toughening.

关 键 词：高强钢 焊接热影响区 电脉冲 奥氏体 增韧 

分 类 号：TG404[金属学及工艺—焊接]