摘要
为了测定6005-T6铝合金焊接接头的疲劳极限,对4 mm厚6005-T6铝合金采用手工MIG焊焊接,并且焊后在试板背面进行通水冷却,使用高频疲劳试验机对焊接试件进行疲劳试验,并绘制了S-N曲线。对疲劳断口形貌和焊接接头的显微组织进行分析,研究了疲劳断裂的原因。结果表明：铝合金手工MIG焊接头在50%存活率情况下,其高周（10^7）疲劳极限应力为125 MPa,S-N拟合曲线为σ（max）=701Nf^-0.127。不同应力状态下疲劳裂纹均萌发于试样的表面。高应力状态下,断口中很难发现扩展辉纹,与静态拉伸断口相似。低应力状态断口扩展区存在大量扩展辉纹。热影响区的粗晶区和晶界聚集的第二相对疲劳性能不利。
In order to determine the fatigue limit of 6005-T6 aluminum alloy welded joint, the 4 mm thick 6005-T6 aluminum alloy was welded by using manual MIG weldingn and the water cooling was used on the back of test plates after the welding, and the fatigue tests of welded specimens were carried out by using high-frequency fatigue testing machine and the S-N curve was also drawn. The morphologies of the fatigue fracture and the microstructure of the welded joint were analyzed to study the causes of fatigue fracture. The results show that the high cycle（107） fatigue limit stress of 6005 aluminium alloy manual MIG welding joint is 125 MPa with the survival rate of 50%, and the S-N curve fitting equation is σmax=701 N-0.127 f.Under different stress states, the fatigue cracks all germinate on the surface of the specimen. Under high stress state, it is difficult to find extended striations in the fatigue fracture, which is similar to the static tensile fracture. Under low stress state,there are a large number of extended striations in the extended region of the fracture. The coarse grain zone of heat affected zone and the second phase aggregated around the grain boundary are bad for fatigue performance.
作者
但楚臣
盛慧章
苏允海
DAN Chuchen1, SHENG Huizhang1, SU Yunhai2(1. CRRC Sifang Co., Ltd., Qingdao 266111, China; 2. Shenyang University of Technology, Shenyang 110870, Chin)
出处
《热加工工艺》
CSCD
北大核心
2018年第3期49-52,共4页
Hot Working Technology
关键词
6005铝合金
手工MIG焊
疲劳性能
扩展辉纹
6005 aluminum alloy
manual MIG welding
fatigue performance
extended striations
作者简介
但楚臣（1984-）,男，湖北赤壁人，工程师，工学学士，主要从事焊接工艺研究：电话：15244216615；E-mail：danchuchen@163．com;通讯作者：苏允海（1980-），辽宁大连人，副教授，工学博士，研究方向：材料焊接及表面强化技术．电话：13709840941；E-mail：289646841@qq．com
