7003铝合金动车柜体的应力腐蚀开裂

发布时间：2018-03-12 18:53

本文选题：铝合金　切入点：应力腐蚀开裂　出处：《材料工程》2015年07期 　论文类型：期刊论文

【摘要】：采用光学显微镜、扫描电镜、能谱分析等手段,对某动车7003铝合金柜体的裂纹进行原因分析。裂纹为沿晶扩展,且有分枝,断口为冰糖状花样,晶面上有发纹、鸡爪纹,经分析裂纹为氢脆起主导作用的应力腐蚀裂纹。通过慢应变速率拉伸实验及恒位移应力腐蚀实验对7003铝合金的应力腐蚀倾向进行评价。慢拉伸实验表明,7003铝合金在3.5%NaCl溶液中的断裂为穿晶与沿晶的混合断裂,在穿晶断裂部分有大量的二次裂纹、解理台阶及河流花样,应力腐蚀敏感指数达0.2。恒位移实验结果显示:经28天腐蚀后,7003铝合金已发生裂纹扩展,长度达700μm,断口的应力腐蚀区存在"舌状凸起"和"凹槽"等形貌,有较明显的应力腐蚀敏感性。
[Abstract]:By means of optical microscope, scanning electron microscope and energy dispersive analysis, the causes of cracks in 7003 aluminum alloy cabinet are analyzed. The cracks are intergranular and branched, the fracture surface is a candy pattern, and there are stripes and chicken claws on the crystal plane. The stress corrosion cracking of 7003 aluminum alloy is evaluated by slow strain rate tensile test and constant displacement stress corrosion test. The slow tensile test shows that the stress corrosion tendency of 7003 aluminum alloy is low. The fracture in 3.5% NaCl solution is a mixed fracture of transgranular and intergranular. There are a large number of secondary cracks, cleavage steps and river patterns in the transgranular fracture part. The sensitivity index of stress corrosion is 0.2. The results of constant displacement experiment show that the crack propagation has occurred after 28 days of corrosion. The length of the fracture is 700 渭 m, and the stress corrosion zone of the fracture has the morphology of "tongue bulge" and "groove", which has obvious stress corrosion sensitivity.
【作者单位】：西南交通大学四川省先进焊接及表面工程技术研究中心;西南交通大学生命科学与工程学院;
【基金】：中央高校基本科研业务费专项资金资助项目(SWJTU12CX047)
【分类号】：TG172.9

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