大型薄壁铝合金闭式叶轮应力去除工艺研究

Research on Stress Removal Technology of Large Thin-Walled Aluminum Alloy Closed Impeller

大型薄壁铝合金闭式叶轮是压缩机等产品的关键部件,也是压缩机内对气体做功的部件。工作时,叶轮通过高速转动对气体做功,使沿径向流过叶轮气体的压力和速度升高,从而完成气体的压缩与运输。铝合金叶轮对铸造质量、力学性能、尺寸稳定性等要求非常高,而铸造后由于壁厚差较大,在薄壁与厚壁的过渡位置会存在大量的残余应力。因此,通过热时效与振动时效的有效结合,设计并试验不同的参数,有效降低了铸件的残余应力,减小了后续加工使用过程中变形的风险。

The large thin-walled aluminum alloy closed impeller is a key component of compressors and other products,and it is also a component that does work on gas in the compressor.When working,the impeller performs work on the gas through high-speed rotation,which increases the pressure and speed of the gas flowing through the impeller in the radial direction,and completes the compression and transportation of the gas.Aluminum alloy impellers have very high requirements for casting quality,mechanical properties,and dimensional stability.After casting,due to the large wall thickness difference,there will be a large amount of residual stress at the transition position between the thin wall and the thick wall.Through the effective combination of thermal aging and vibration aging,different parameters are designed and tested,which effectively reduces the residual stress of the casting,reduces the risk of deformation during subsequent processing and using.