基于田口法的超大型涡轮盘锻造工艺参数多目标优化

Multi-object Optimization of Forging Process Parameters for Super Large Turbine Disc Based on Taguchi Method

直径超过2 m的超大型涡轮盘的锻造载荷接近甚至超过了国内最大压力机的极限(800 MN),是真正的极限制造。因此,保持良好的力学性能和控制锻造载荷是超大型涡轮盘热锻生产过程中必须同时兼顾的2个因素。基于田口法设计了25组不同的热锻参数,采用SNR和ANOVA方法对有限元模拟结果进行多目标优化分析,获得了最优锻造载荷和最均匀细化的再结晶组织,确定了极端制造条件下的最佳工艺参数组合(温度1120℃,应变速率0.06 s^(-1),预锻尺寸985/610/475 mm,模具温度280℃)。各参数对模拟结果的重要性顺序如下:变形温度>应变速率>坯料形状>>模具温度。使用最佳参数组合获得的实验结果与数值模拟结果吻合较好,表明该方法可以避免大量实验和数值模拟工作量,有效地控制超大型锻件的载荷和微观组织。

The forging load of super large turbine disc with a diameter over 2 m may approach or even surpass the limit of 800 MN of the largest press machine in China,which is the extreme manufacturing.Thus,maintaining good mechanical properties and controlling forging load are two key factors during the forging process of super large turbine disc.25 groups of forging parameters was designed based on Taguchi method.The multi-objective optimization of finite element method simulation results was conducted by SNR and ANOVA methods.Results show that the most uniform and refined recrystallization microstructures are obtained under optimal forging load.The optimal combination of process parameters is determined under extreme manufacturing condition:temperature=1120 ℃,strain rate=0.06 s^(-1),pre-forging size=985/610/475 mm,and die temperature=280 ℃.The order of importance of each parameter to the simulation results is as follows:temperature>strain rate>billet shape>>die temperature.The experimental results obtained under the optimal parameters combination show good agreement with the simulated results,which demonstrates that this approach may be used to manage the load and microstructure of super large forgings while avoiding a significant number of experiments and numerical simulations.