6061铝合金中厚板生产中晶粒度的控制方法

Control Method of Grain Size in Production of 6061 Aluminum Alloy Plate

粗大晶粒容易导致6061铝合金中厚板表面出现橘皮纹缺陷和差的阳极氧化效果。本文通过调整6061铝合金的合金成分、热轧工艺、固溶处理工艺,分别研究了各工序中控制晶粒度的方法。结果表明:增加合金中Mn、Cr含量可以起到细化晶粒的作用;在热轧过程中,板材的终轧温度、最后道次的加工率会影响板材表层的再结晶程度,较低的终轧温度、较小的最后道次的加工率可以防止板材表层发生再结晶;在固溶过程中,当板材心部达到固溶温度后,应尽快进行淬火,以防止板材表层的晶粒度随着加热时间延长而增大。本文提出了防止6061铝合金中厚板晶粒粗大的优化工艺参数。

Coarse grains easily lead to orange peel defects and poor anodizing effect of the surface of 6061 aluminum alloy plate. By adjusting the alloy composition, hot rolling process and solid solution treatment process of 6061 aluminum alloy, the method of controlling grain size in each process was studied. The results indicate that increasing the Mn, Cr content in the alloy can refine the grain. In the process of hot rolling, the final rolling temperature and the processing rate of the final pass will affect the recrystallization degree of the surface layer of the plate. The lower final rolling temperature and processing rate of final pass can prevent the surface layer from recrystallization. In the process of solid solution, when the core of the plate reaches the solid solution temperature, it should be quenched as soon as possible to prevent the grain size of the surface layer of the plate from increasing with the heating time. The optimized process parameters to prevent coarse grain size of 6061aluminum alloy medium thick plate were proposed.