K418合金车用增压涡轮熔模铸造过程数值模拟及热裂预测

摘要

针对K418合金车用增压涡轮铸件极易出现热裂缺陷的现象,结合工厂实际生产条件,应用ProCAST铸造模拟软件对K418合金车用增压涡轮的充型过程、凝固时间以及凝固过程中的温度场、缩孔缩松形成过程和应力场进行了模拟.基于分析的结果,预测了涡轮中存在的热裂缺陷,模拟结果与实际生产情况吻合良好.分析结果表明,涡轮叶梢处容易产生热裂纹的主要原因是凝固过程中热应力不均引起的.%Hot tearing defect easily occurs in K418 superalloy for auto turbocharger turbine. Filling process, solidification time, the temperature field, the forming process of shrinkage cavity and porosity and the stress field in the solidification process are simulated concerning with the practical production conditions. The hot tearing defect is predicted on the basis of the analysis results, and the simulation results are basically in accordance with the current production. The analysis results show that the main reason for the hot tearing of the turbine in this paper is the uneven distribution of the thermal stress during the solidification process.