冷轧加工率对5182-O铝合金汽车板性能和织构的影响  

Effect of Cold Rolling Reduction Rate on Texture and Mechanical Property of 5182-O Aluminum Alloy Used in Automotive Sheets

作　　者：李涛 孟双 徐志远 杨立民 迟蕊 刘明诏 徐扬帆 LI Tao;MENG Shuang;XU Zhiyuan;YANG Limin;CHI Rui;LIU Mingzhao;XU Yangfan(Nanshan Aluminum Flat-rolled Product Division,Shandong Nanshan Aluminum Co.,Ltd.,Shandong Longkou 265713,China)

机构地区：[1]山东南山铝业股份有限公司南山铝业板带事业部,山东龙口265713

出　　处：《精密成形工程》2024年第5期124-131,共8页Journal of Netshape Forming Engineering

基　　金：山东省重点研发计划(2021SFGC1001)。

摘　　要：目的研究冷轧变形量对5182铝合金汽车板力学性能、塑性应变比、金相及织构的影响,系统解释5182铝合金汽车板的强化机理和成形性变化机理。方法采用X射线衍射仪、金相显微镜和万能拉伸试验机研究不同冷轧加工率下5182-O铝合金的力学性能和显微组织变化规律。结果50%和75%冷轧加工率的样品强度无明显差异,25%冷轧加工率的样品偏低约3 MPa。塑性应变比加权平均值rm随冷轧加工率的增大而减小,几乎呈线性关系,塑性应变比各向异性度Δr则先减小后增大,延伸率和应变硬化指数则无明显差异。当冷轧加工率从25%增至50%时,平均晶粒尺寸减小了约24%,当冷轧加工率从50%增至75%时,平均晶粒尺寸仅减小了1~2μm。不同冷轧加工率下的5182铝合金连退再结晶后均表现出较弱的织构强度,Cube织构未占主导地位,仍保留了较多的轧制织构。S、Copper和Brass织构的体积分数随冷轧加工率的增大而有所减小,Goss和Q织构的占比有所增大,Cube织构的占比则变化不大。结论冷轧加工率影响了5182-O铝合金汽车板连退后的晶粒尺寸,进而改变了强度。晶粒尺寸和屈服强度的关系符合经典Hall-Petch以及新Hall-Petch关系式。受不同再结晶形核机制竞争关系的影响,轧制织构随冷轧加工率的增大而稍有减少,导致45°方向的塑性应变比和rm逐渐减小,Δr则先减小后增大。The work aims to study the effects of cold rolling reduction rates on the mechanical property,plastic strain ratio,metallography,and texture of 5182 aluminum alloy used in automotive sheets,and systematically explain the strengthening mechanism and formability change mechanism of 5182 aluminum alloy automotive sheets.The mechanical property and micro-structure of 5182-O aluminum alloy were studied by X-ray diffractometer,metallographic microscope,and universal tensile testing machine.There was little difference in strength between samples with 50%and 75%cold rolling reduction rates,and the strength of the sample with 25%cold rolling reduction rate was about 3 MPa lower than that of other samples.The weighted av-erage of plastic strain ratio rm value decreased almost linearly with the increase of the cold rolling reduction rate,while the de-gree of planar anisotropy of plastic strain ratioΔr value decreased first and then increased.There was little difference in elonga-tion and strain hardening index between different cold rolling reduction rates.When the cold rolling reduction rate increased from 25%to 50%,the average grain size decreased by about 24%,and when the cold rolling reduction rate increased from 50%to 75%,the average grain size decreased by only 1-2μm.The 5182 aluminum alloy samples at different cold rolling reduction rates showed weak texture strength after recrystallization.The Cube texture was not dominant,and retained much rolling tex-tures.The volume fraction of S,Copper and Brass texture decreased with the increase of the cold rolling reduction rate,while the proportion of Goss and Q texture increased,and there was little change in the proportion of Cube texture.The strength of 5182-O aluminum alloy automotive sheets is changed by the influence of the cold rolling reduction rate on grain size.The rela-tionship between grain size and yield strength is in good agreement with the classical and the novel Hall-Petch relations.Af-fected by the competition between different recrystallization nucleatio

关 键 词：5182铝合金 冷轧 强度 塑性应变比 织构 

分 类 号：TG146.21[一般工业技术—材料科学与工程]