摘要
通过试板试验，研究了多次返修（次数从１－７次不等）对锅炉用钢２０ｇ焊接接头组织与性能的影响。结果表明，对２０ｇ接头焊缝进行超过３次返修以后，其焊接热影响区的常温冲击韧性ａｋ、接头抗拉强度σｂ以及焊缝金属、熔合线和热影响区的硬度值ＨＶ等常规机械性能的变化仍在允许范围之内。弯曲试验表明，接头焊逢的冷弯性能亦无变坏迹象。金相组织观察显示，随着返修次数的增加，Ｈｅａｔ－ａｆｅｃｔｅｄｚｏｎｅ（ＨＡＺ）的过热区组织粗化不明显。文中还就改善多次返修后的焊缝质量所应采取的措施进行了探讨。
The effects of 20 g welding joints′ structures and properties are studied through experiments on samples after they have been rewelded several times(from 1 to 7 respectively). The results show that changes of normal mechanical properties of the welding joints such as normal impact toughness ( a k )in HAZ(heat affected zone), tensile strength of the weld( σ b )and Vickers hardness(H V)in weld metal, weld junction and HAZ etc. are still within the permissible range even after they have been rewelded over three times; Bending tests give no evidence of degrading of the joints′ bent properties under normal atmospheric temperature. Metallographic observation illustrates that grains in overheated zone of HAZ don′t grow obviously as the number of times of repairing welding gradually increases. In the end, the possible measures on how to improve the quality of the weld are also discussed.
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
1998年第3期275-282,共8页
Journal of Nanjing University of Aeronautics & Astronautics
