铝合金大型锻件淬火过程的有限元模拟

采用Deform V11有限元软件,计算了T形7N01铝合金锻件的表面综合换热系数,仿真模拟了锻件淬火过程中的温度场、应力场与形变位移变化规律,分析了温度与热应力对锻件淬火形变的影响与作用机制。结果表明,淬火初期因温度梯度(最大温差达225 ℃)与热应力巨大差异,锻件肋板一侧在淬火时间为10 s时产生了最大程度的弹性与塑性变形,远大于无肋一侧,弯曲曲率增大;淬火中期锻件主要发生弹性形变,厚度大的肋板一侧收缩变形加剧,曲率变小,50 s时锻件基本不再变形;淬火后期阶段热应力趋于零,锻件冷却产生微量弹性形变,淬火结束后,锻件整体产生趋向肋板一侧的塑性弯曲变形,曲率半径大于加热前。

Finite element simulation of quenching process of large aluminum alloy forgings

Finite element software DEFORM V11 was used to calculate the surface integrative heat-exchange coefficient of T-shape 7N01 aluminum alloy forgings, to simulate the change rules of temperature field, stress field and deformation displacement during the quenching process of forgings, and to analyze the influence and mechanisms of temperature and heat stress on the quenching deformation of forgings. The results show that at the preliminary stage of quenching, due to the big differences in temperature gradient (the maximum temperature difference reached 225 ℃) and heat stress, the forgings generate the maximum elastic and plastic deformation at quenching time of 10 s on the side with ribbed plate, which is much bigger than that on the side without ribbed plate, and the bending curvature increases. At the middle stage of quenching, the forgings mainly generate elastic deformation, but contraction deformation is intensified on the side with thicker ribbed plate, the curvature decreases, and the forgings generate basically no further deformed at 50 s. And at the later stage of quenching, as the heat stress tends to zero, the forgings generate tiny elastic deformation due to cooling, and after the end of quenching, the forgings generate plastic bending deformation towards the ribbed plate as a whole, with greater radius of curvature than that before heating.