大型船用曲轴曲拐弯锻过程的计算机模拟与工艺优化研究

Study on Process Optimization and Computer Simulation of Bending Process of Large Marine Crankthrow

采用计算机模拟和试验手段研究了传统工艺曲拐弯锻的过程，指出了传统工艺的不足和锻造过程容易出现的各种典型缺陷。采用逆推法确定了改进工艺后预成形毛坯形状，优化了毛坯的形状因子，有针对性地提出了解决各种缺陷的措施。在此基础上对改进的工艺进行了计算机模拟，模拟结果表明，改进后的工艺能够消除喇叭口、裂纹、“细腰”、减薄等缺陷；毛坯变形抗力为传统工艺的72％；毛坯截面积减小，可节省原材料约15％。最后对改进的工艺进行了试验，得到了合格的曲拐毛坯锻件，验证了模拟的准确性。所建立的模型和研究方法为进一步优化锻压工艺和今后开发其它型号的大型曲轴曲拐产品提供理论指导和技术保障。

Study the traditional bending and experiment, and point out its deficiency process of crankthrow by means of computer simulation and various typical defects occurred in the process of bending. After improving process, confirm preformed billet shape and optimized shape factor by backstepping method, and put forward measures to solve those defects. On this basis, carry out computer simulation for improved process. The result shows that some defects are eliminated, such as bellmouthed hole, crack, ＂thin-waist＂, thickness reduction; billet deformation rate is 72% of the traditional process. About 15% raw material can be saved with the decrease of billet cross section area. Finally, make an experiment on improved process, which achieved a qualified forging of crankthrow billet and verified the accuracy of simulation. The established model and research method provides theoretical guidance and technical support for further forging process optimization and other types of large crankthrow development.