摘要
目的研究7A52铝对接焊拉伸试样、25CrMnSiA钢对接焊拉伸试样的海洋大气应力腐蚀行为。方法利用自行设计制作的恒载荷大气应力腐蚀试验装置,在海南万宁站海洋大气环境中,分别采用7A52铝对接焊拉伸试样、25CrMnSiA钢对接焊拉伸试样进行海洋大气应力腐蚀试验研究。对试验中断裂的试样和未断裂的试样,进行表面腐蚀形貌、断口形貌、显微组织、显微硬度分布等分析。结果 7A52铝焊接件断裂在焊接部位,Cl-富集于SCC部分的含钙或含硫的第二相质点,促进了7A52铝焊接件应力腐蚀开裂。海洋大气应力腐蚀试验的25CrMnSiA钢焊接件断裂在母材部位,而实验室拉伸试验断裂在焊接部位。结论两种焊接件在海南海洋大气环境下均存在应力腐蚀开裂,裂纹萌生、扩展于朝向海洋方向的试样表面,存在"风脆"现象。
Objective To study stress corrosion of butt welding tensile specimen of 7A52 aluminum alloy and 25CrMnSiA steel in marine atmosphere environment. Methods Constant load stress corrosion test device, which was designed and manufactured by ourselves, was adopted to study stress corrosion of 7A52 aluminum alloy butt welding tensile specimen and 25CrMnSiA steel butt welding tensile specimen in marine atmosphere environment. Specimen with crack- ing or without cracking in the test were analyzed from corrosion morphology, fracture surface morphology, microstructure, microhardness distribution, etc. Results 7A52 aluminum weldments fractured in the weld where C1 concentrated in second phase particles that contain calcium and/or sulfur promoted stress corrosion cracking of 7A52 aluminum weld- ments. 25CrMnSiA weldments fractured in the base metal in the marine atmosphere corrosion test, while it was fractured in the weld in the laboratory tensile test. Conclusion Both kinds of weldments have stress corrosion cracking in Hainan marine atmosphere, crack initiated and propagated in the seaward surface which called ＂wind embrittlement＂.
作者
张伦武
郑林
朱蕾
封先河
窦世涛
周上祺
黄维刚
ZHANG Lun-wu ZHENG Lin ZHU Lei FENG Xian-he DOU Shi-tao ZHOU Shang-qi HUANG Wei-gang(No.59 Institute of China Ordnance Industry, Chongqing 400039, China Chongqing Key Laboratory of Environmental Effect and Protection, Chongqing 400039, China Chongqing University, Chongqing 400044 Sichuan University, Chengdu 610065, China)
出处
《装备环境工程》
CAS
2017年第6期109-115,共7页
Equipment Environmental Engineering
关键词
高强铝合金
高强钢
焊接
应力腐蚀
海洋大气环境
high strength aluminum alloy, high strength steel, weld, SCC, marine atmosphere environment
