中南大学学报（自然科学版）2018，Vol.49Issue(4)：802-808,7.DOI:10.11817/j.issn.1672-7207.2018.04.005
轨道交通用7003铝合金型材失效行为分析
Failure behavior analysis of railway 7003 aluminum alloy extrusions
摘要
Abstract
The failure behavior analysis of rail railway 7003 aluminum alloy extrusions was studied by optical microstructure, scanning electron microscopy(SEM), transmission electron microscopy (TEM) and slow strain rate tensile stress corrosion testing, etc. The results show that the crack of extrusions extends along the grain boundary and bits of branch crack extend outward. Fracture morphology of failure extrusions is sugar lump pattern features, and also the fracture surface is attached to aluminum, zinc oxide and bits of chlorides and sulfides. The intergranular brittle fracture is caused by stress corrosion. The tensile strength and break time of extrusions sample are respectively 181.5 MPa and 5.1 h in 30 g/L NaCl+10 mL/L HCl corrosion solution; The tensile strength and break time of extrusions sample in air are 320.3 MPa and 27.7 h, respectively. Stress corrosion sensitivity index (ISSRT) is 0.46. The small size, high density and continuous chain distribution of grain boundries precipiates which easily become anodic corrosion channel during the corrosion process, are the main causes of high sensitivity to stress corrosion.关键词
7003铝合金型材/失效分析/沿晶脆性断裂/应力腐蚀/连续析出相Key words
7003 aluminum alloy/failure behavior analysis/intergranular brittle fracture/stress corrosion/continuous precipiates分类
矿业与冶金引用本文复制引用
胡桂云,陈康华,陈送义,姜慧丽..轨道交通用7003铝合金型材失效行为分析[J].中南大学学报（自然科学版）,2018,49(4):802-808,7.基金项目
国家重点研发计划(2016YFB0300801) （2016YFB0300801）
国家重点基础研究计划(973计划)项目(2012CB619502) （973计划）
国家自然科学基金资助项目(51201186) （51201186）
国家重大科研仪器设备研制专项(51327902) （51327902）
研究生自主探索创新项目(2016zzts317)(Project(2016YFB0300801) supported by the National Key Research and Development Program of China （2016zzts317）
Project(2012CB619502) supported by the National Basic Research Program (973 Program) of China （2012CB619502）
Project(51201186) supported by the National Natural Science Foundation of China （51201186）
Project(51327902) supported by the Major Research Equipment Development Projects of National Natural Science Foundation of China （51327902）
Project(2016zzts317) supported by the Graduate Students Explore Innovation Project) （2016zzts317）
