K4169高温合金机匣热控凝固工艺的数值模拟及优化

Numerical Simulation and Process Optimization of Thermally Controlled Solidification of K4169 Superalloy Engine Case

高温合金机匣是典型的大型复杂薄壁结构件,在整体熔模铸造中极易产生缩松缺陷。为了提高成品质量,采用Pro CAST软件对现行的热控凝固工艺过程进行数值模拟。通过对预热、浇注和抽拉三个过程的全面分析,发现镁砖的蓄热及其对型壳支点部位散热通道的遮挡是铸件缩松缺陷的产生主因。针对该现状,采取减小镁砖的体积及支点数等措施对型壳装炉方式进行了改进。模拟先行研究与浇注试验结果均表明,在优化工艺下,铸件法兰的散热均匀性显著提高,缩松缺陷得到有效控制。

Abstract： Superalloy engine case is a typical large complex thin-wall component, in which porosity can easily occur during the investment casting process. In order to improve the quality of products, numerical simulation of thermally controlled solidification process was carried out by using ProCAST software. The barrier of heat radiation and heat storage of magnesia bricks were found to be the main causes of casting defects through comprehensive analysis of preheating, filling and withdrawal processes. To solve this problem, original process was optimized by reducing the volume and the number of magnesia bricks, which made the heat dissipation of casting flange more uniform and decreased porosity significantly according to the results of simulation and experiment.