冷轧及退火工艺对5083铝合金薄板组织性能的影响

Study on the effect of cold rolling and annealing process on the microstructure and mechanical properties of 5083 aluminum alloy sheet

利用金相显微镜、拉伸试验机、弯曲试验机对5083O铝合金板材在不同冷轧加工率(5%~40%)和不同退火温度(120~280℃)下的微观组织、拉伸力学性能、弯曲性能进行了系统研究。研究结果表明,5083O铝合金板材晶粒为细小均匀的等轴晶。随着冷轧加工率从5%增加至40%,晶粒逐渐被压扁、拉长。冷轧加工率不大于10%的板材折弯性能良好;当冷轧加工率为20%时,弯曲样品外侧出现凹凸不平的颈缩区域;当冷轧加工率增加到30%时,折弯样品出现微裂纹;当加工率增加到40%时,裂纹数量增多、尺寸增大。随着退火温度从120℃增加到280℃,不同冷轧加工率的板材屈服强度和抗拉强度呈单调下降趋势,而且屈服强度的降幅大于抗拉强度的降幅,断后伸长率呈单调增加趋势。当冷轧加工率为20%时,需对板材进行200℃以上的退火处理才能满足折弯性能要求;当冷轧加工率增加至30%和40%时,需要对板材进行240℃以上的退火处理才能满足折弯性能要求。

This paper systematically studied the microstructure,tensile mechanical proper-ties,and bending properties of 5083O aluminum alloy sheet under different cold rolling re-ductions(5%-40%)and annealing temperatures(120℃-280℃)with metallographic microscope,tensile testing machine,and bending testing machine.The results show that grain size of 5083O aluminum alloy sheet is fine and uniform equiaxed.As the cold rolling reduction increases from 5%to 40%,the grain is gradually flattened and elongated.The bending performance of sheet with a cold rolling reduction≤10%is good.When the cold rolling reduction is 20%,uneven necking areas appear on the outer side of the bent sample.When the cold rolling reduction increases to 30%,microcracks appear in the bent sample.When the reduction increases to 40%,the number and size of cracks increase.For sheet with different cold rolling reduction.As the annealing temperature increases from 120 ℃ to 280℃,the yield strength and tensile strength show a monotonic decreasing trend,the decrease of yield strength is greater than that of tensile strength,and the elongation after fracture shows a monotonic increasing trend.When the cold rolling reduction is 20%,annealing treatment above 200℃ is required for the sheet to meet the bending performance requirements.When the cold rolling reduction increases to 30%and 40%,annealing treatment above 240℃ is required for the sheet to meet the bending performance requirements.