TC4钛合金EBW和TIG焊接头断裂韧性对比分析  

Comparative analysis of fracture toughness of EBW and TIG welded joints of TC4 titanium alloy

作　　者：王东坡[1] 张子璇 高文斌 邓彩艳[1] 梁行 王婷 WANG Dongpo;ZHANG Zixuan;GAO Wenbin;DENG Caiyan;LIANG Hang;WANG Ting(Tianjin University,Tianjin,300072,China;Jiangsu University of Science and Technology,Zhenjiang,212100,China;Shenyang Zhongtai Equipment Manufacturing Co.,Ltd.,Shenyang,110206,China)

机构地区：[1]天津大学,天津300072 [2]江苏科技大学,镇江212100 [3]沈阳中钛装备制造有限公司,沈阳110206

出　　处：《焊接学报》2023年第8期7-13,I0003,共8页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51875402);江苏省自然科学基金青年基金项目(BK20201000).

摘　　要：采用电子束焊和氩弧焊方法制备的TC4钛合金接头,在4种温度条件下,测试了其焊缝、热影响区及母材的断裂韧性,并结合断口形貌、硬度分布及微观组织对比分析了断裂韧性测试结果.结果表明,TC4钛合金TIG焊接头焊缝及热影响区的断裂韧性优于钛合金母材,CTOD值随温度下降而降低;相较之下,EBW焊接头焊缝断裂韧性值较母材更低,热影响区断裂韧性与母材较接近,温度变化对其CTOD值无显著影响.钛合金TIG焊接头焊缝区域具有较低硬度值,其网篮状α相和较低比例的马氏体分布是其断裂韧性较高的根本原因;而钛合金EBW焊接头焊缝中针状马氏体的分布导致其局部硬度较高,并降低了断裂韧性.For TC4 titanium alloy joints prepared by electron beam welding(EBW)and tungsten inert-gas arc welding(TIG),the fracture toughness of the weld,heat-affected zone and base metal were tested at four temperatures.Furthermore,the fracture toughness test results were analyzed by comparing the fracture morphologies,hardness distributions and microstructures.It is found that the fracture toughness of TC4 titanium alloy TIG joint weld or heat-affected zone is better than that of titanium alloy base metal,and the CTOD value decreases with the reduction of test temperature.In contrast,the fracture toughness for EBW joint seam is lower than that of the base metal,and the CTOD value for HAZ is close to that for base metal.Meanwhile,the change of temperature has no significant effect on the corresponding CTOD values.The weld in the titanium alloy TIG joint has a relatively lower hardness value,which is basket-shapedαPhase and lower proportion of martensite distribution.Those are the basic reasons for its higher fracture toughness.The acicular martensite distribution in titanium alloy EBW joint leads to the higher local hardness and lower fracture toughness.

关 键 词：TC4钛合金 断裂韧性 电子束焊 钨极氩弧焊 

分 类 号：TG407[金属学及工艺—焊接]