深冷处理消除7050铝合金残余应力的研究

提出了一种被称为“反淬火法”的深冷处理新工艺，将铝合金构件浸入液氮中深冷后，采用一种特制的QCW—01型有机介质进行“反淬火”，从而消除7050铝合金的残余应力．探讨了深冷处理工艺路线与工艺参数对应力消除效果与机械性能的影响．采用x射线衍射法测定应力消除前后铝合金试样的残余应力，利用电导率涡流检测技术与拉伸试验相结合的方法来评价铝合金深冷处理后的抗应力腐蚀性与机械性能等质量指标．得到了在兼顾满足机械性能要求前提下取得最佳应力消除效果的深冷处理工艺．经实验证实，在该深冷处理中采用QCW—01型有机介质的残余应力消除率达到58％，远远高于采用沸水急热的传统深冷处理工艺的应力消除率．

Relief of residual stresses in 7050 aluminum alloy by deep cryogenic treatment

A novel deep cryogenic treatment, known as uphill quenching, was presented for relieving residual stresses in 7050 aluminum alloy parts.The parts was submerged in liquid nitrogen and immediately uphill quenched in proprietary QCW-01 quenchant. The objective of this study was to investigate the effect of technological process and parameters of the uphill quenching process on the thermal stress relief and mechanical properties in 7050 aluminum specimens. Residual stresses were measured by X-ray diffraction, and eddy current electrical conductivity testing was applied to control the variation of mechanical properties. The optimum uphill quenching process resorted to an attempt to combine maximum stress relief with the required levels of mechanical properties. Experimental results showed that the stress relief obtained in this treatment reached a level of 58%, higher than that of the traditional treatment by quenching in boiling water.