多质量目标的曲轴NTR弯曲镦锻成形工艺优化

Optimization of crankshaft NTR upset-bending process based on multi-objective quality

研究提高曲轴NTR弯曲镦锻外形质量的工艺参数优化方法。以中速船用6G32曲轴为例,借助数值模拟方法预测曲轴成形结果,设定曲轴外形质量评价准则。应用正交实验方法设计实验方案,模拟多种工艺条件下曲轴弯曲镦锻成形。根据实验结果,以降低曲轴成形塌角缺陷、减少飞边量、降低设备载荷为目标,采用响应面分析方法,建立评价指标与各工艺参数的函数表达式,优化始锻温度、NTR设备肘杆终锻角、模具运动方式、模具运行速度等曲轴NTR弯曲镦锻工艺参数。

Optimization method of crankshaft NTR（New TR） upset-bending process was studied to improve the shape quality of the forgings.A numerical simulation was accomplished for the medium-speed marine 6G32 crankshaft.Based on the simulation results,the crankshaft shape quality evaluation criteria were set up.Orthogonal test was carried out to predict the crankshaft forming results under a variety of conditions.According to the experimental results,the function expression of the quality evaluations and the process parameters were established using response surface methodology.Multi-objective optimization of crankshaft NTR upset-bending process was implemented and the best set of process parameters was obtained including the initial forging temperature,the final angle of NTR toggle,the moving mode and velocity of the mold,etc.It could reduce the crankshaft forming flash amount and the equipment load with the guarantee of the shape quality.