工艺参数对下注式铸轧2624铝合金偏析行为和性能影响

Effect of process parameters on segregationbehavior and properties of bottom cast-rolling_(2)624 aluminum alloy

借助模拟铸轧区流场,并采用SEM、EPMA、DSC、电导率和常温拉伸性能测试手段,详细研究了不同工艺参数对下注式双辊铸轧2624铝合金偏析行为和性能的影响,分析了铸轧过程中偏析的产生机理。结果表明:下注式双辊铸轧的2624铝合金边部出现大尺寸带状偏析,溶质元素呈现宏观反偏析现象;浇注温度和铸轧速率的降低可以增强涡流的峰值速率,减弱宏观偏析程度;冷却速率的增强可以减弱微观偏析程度,降低电导率;此外,铸轧板的屈服强度、抗拉强度和伸长率随着浇注温度和铸轧速率的降低逐渐增高,合金的力学性能得到改善。

The effects of different process parameters on the segregation behavior and properties of bottom twin-roll casting_(2)624 aluminum alloy were studied in detail by simulating the flow field in the cast-rolling zone and using SEM,EPMA,DSC,electrical conductivity and tensile properties at room temperature.The mechanism of segregation in the cast-rolling process was analyzed.The results show that the large size banded segregation appears at the edge of bottom twin-roll casting_(2)624 aluminum alloy,solute elements exhibit macroscopic inverse segregation.The decrease of pouring temperature and casting speed can enhance the peak velocity of vortex and reduce the degree of macrosegregation.The increase of cooling rate can weaken the degree of microsegregation and reduce the conductivity.In addition,the yield strength,tensile strength and elongation of the cast-rolled sheet increase with the decrease of pouring temperature and casting speed,and the mechanical properties of the alloy are improved.