热处理工艺对模具用7A04超硬铝合金晶间腐蚀和疲劳性能的影响  

Effects of Heat Treatment on Intercrystalline Corrosion and Fatigue Properties of 7A04 Superhard Aluminum Alloy Used in Die

作　　者：艾翠蓉[1] 黄镇[1] 李智丽[1] 王飞 AI Cui-rong;HUANG Zhen;LI Zhi-li;WANG Fei(College of Mechanical and Electrical Engineering,Hubei Three Gorges Polytechnic,Yichang 443000,China;CRRC Qingdaosifang Locomotive&Vehicle Co.,Ltd.,Qingdao 266111,China)

机构地区：[1]湖北三峡职业技术学院机电工程学院,湖北宜昌443000 [2]中车青岛四方机车车辆股份有限公司,山东青岛266111

出　　处：《材料保护》2020年第8期101-104,共4页Materials Protection

基　　金：宜昌市自然科学研究项目(A20-3-027)资助。

摘　　要：为了提高模具用7A04超硬铝合金的耐腐蚀性能,分别采用不同的工艺条件对铸锭试样进行热处理,并对热轧合金试样进行退火,考察了板材的耐蚀特性及其抗疲劳性。研究结果表明:采用热处理工艺得到的合金试样只形成了很小的晶间腐蚀深度,满足二级标准,同时质量损失程度较低,具备优异晶间抗蚀能力。在晶界区域形成了断续分布的高镁β组织,其含量也较低,具备较强的抗晶间腐蚀性能,当腐蚀扩展到β相所在区域时便会停止。各处理工艺得到的板材形成了不同的断裂强度,应变损失也存在较大差异。所有热处理工艺下试样都表现为韧性断裂的特征,只形成了少量没有溶解的小尺寸颗粒,在韧窝内还存在大量小韧窝。In order to improve the corrosion resistance of 7A04 superhard aluminum alloy used in the mold,different technological conditions were used to heat treat the ingot sample,and the hot rolled alloy sample was annealed. The corrosion resistance and fatigue resistance of the plate were studied. Results showed that the alloy samples obtained by heat treatment process only had a very small intergranular corrosion depth,which met the secondary standard,and the quality loss degree was low,showing excellent intergranular corrosion resistance. The high magnesium beta structure with discontinuous distribution in the grain boundary region was also low in content and had strong resistance to intercrystalline corrosion,which would stop the corrosion when the corrosion extended to the region where the beta phase was located. The fracture strength of the plates obtained by each treatment process was different and the strain loss was quite different. Under all heat treatment processes,the samples showed the characteristics of ductile fracture. Only a small number of undissolved particles of small size were formed,and a large number of small dimples existed in the dimples.

关 键 词：7A04合金 热处理 腐蚀性能 疲劳性能 

分 类 号：TG457.14[金属学及工艺—焊接] TG172