淬火+时效对6061铝合金挤压圆棒硬度的影响

Effects of Quenching and Aging on Hardness of 6061 Aluminum Alloy Extrusion Rod

采用力学性能检测、金相组织分析和扫描电子显微镜观察的方法,研究了挤压车间生产的6061-T6圆棒硬度偏低的原因,并探索了硬度大小与其淬火时效工艺的关系。结果表明,6061/T6挤压圆棒硬度不达标的主要原因是在线淬火温度较低,Mg2Si相固溶不充分,β’/β’强化相析出受限;其次是时效温度偏低,时效析出不完全。通过改进挤压工艺及热处理制度,适当提高在线淬火温度和时效温度,可以改善6061/T6挤压圆棒硬度偏低的问题。

By means of mechanical property test,metallographic analysis and scanning electron microscope(SEM),the reason of low hardness of 6061-T6 rod produced in extrusion workshop was studied.The relationship between the hardness and the quenching aging process was also explored.The results show that,the main reason that the hardness of 6061-T6 extruded rod is not up to the standard is that the solution of Mg2Si phase is not sufficient at low quenching temperature on line and the precipitation ofβ’/β’enhanced phase is limited.Secondly,the aging temperature is low and the precipitation is incomplete.The problem of low hardness of 6061-T6 extrusion rod can be improved by improving the extrusion process and heat treatment system and increasing the on-line quenching temperature and aging temperature appropriately.