回归再时效对7150铝合金力学和腐蚀性能的影响  

Effects of retrogression and re-aging on mechanical properties and corrosion behavior of 7150 aluminum alloy

作　　者：梁帅 刘显东[2] 蒋大鸣[1] LIANG Shuai;LIU Xian-dong;JIANG Da-ming(School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150000,China;Northeast Light Alloy Co. ,Ltd.,Harbin 150060,China)

机构地区：[1]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150000 [2]东北轻合金有限责任公司,黑龙江哈尔滨150060

出　　处：《轻合金加工技术》2019年第3期57-64,71,共9页Light Alloy Fabrication Technology

基　　金：哈尔滨市科技攻关项目(2014AB4AG025-1)

摘　　要：回归工艺对回归再时效(RRA)的7150铝合金性能有着重要的影响,通过调整回归温度和回归时间对合金进行了RRA处理,并进行了硬度、导电率、力学性能和晶间腐蚀性能的测试与分析。结果表明,回归阶段硬度变化曲线都是先降低至谷值,然后增长至峰值,之后又单调降低。较低的回归温度(170℃)导致合金的硬度变化趋势缓慢。170℃回归290 min后合金的抗拉强度为550 N/mm2,再时效后RRA态合金的抗拉强度高达604 N/mm2,屈服强度高达558 N/mm2,在保证合金强度略优于T6时效态前提下,屈服强度提升了6. 28%,晶间腐蚀的最大腐蚀坑深度为52. 8μm。The retrogression process has an important effect on the performance of RRA( retrogression and re-aging) 7150 aluminum alloy. RRA treatment was carried out on the alloy by adjusting the retrogression temperature and retrogression time. Then the hardness,conductivity,mechanical properties and intergranular corrosion performance were tested and analyzed. The results show that the hardness curves of the retrogression stage are reduced to the valley value,increased to the peak value,and then decreased monotonously. The lower retrogression temperature of 170℃ results in slower variation of the hardness. After retrogressed 290 min at 170℃,the tensile strength of the alloy is 550 N/mm^2,and the tensile strength of the alloy is about 604 N/mm2 and the yield strength is up to 558 N/mm^2 after RRA170-290 aging. The yield strength is improved by 6. 28% under the condition that the strength of the alloy is slightly better than that of T6. The maximum corrosion depth of intergranular corrosion is 52. 8 μm.

关 键 词：7150铝合金 回归再时效(RRA) 力学性能 晶间腐蚀 

分 类 号：TG166.3[金属学及工艺—热处理]