铸造工艺对一种铸造高温合金性能及其稳定性的影响  

Effect of Casting Parameters on Mechanical Properties of a Superalloy

作　　者：陈伟[1] 李长春[2] 李辉[2] 陈光[1] 楼琅洪[2] 

机构地区：[1]南京理工大学材料科学与工程系,江苏南京210094 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《铸造》2005年第9期871-874,共4页Foundry

基　　金：国家863计划资助项目(2002AA305208)。

摘　　要：研究了铸造工艺对一种精铸Inconel718C改型合金凝固显微疏松形成倾向性、成分偏析、合金组织及性能稳定性的影响。研究结果表明,随凝固冷却速率的降低,显微疏松形成倾向性降低,合金持久寿命稳定性提高。但随凝固冷却速率降低,晶粒尺寸增大,平均持久寿命降低。与Inconel718 C合金相比,改型合金在更高的温度和应力水平下,表现出良好的拉伸性能和持久性能。Less optimized casting parameters can cause micro-porosity, which is very detrimental to the stress rupture and fatigue properties of the aerospace components. The consistency of mechanical properties demands precise control of casting parameters, in particular, of mould temperature and pouring temperature. Effect of casting conditions on stress-rupture property and its consistency of a modified Inconel 718C superalloy were studied. New feeding system was designed to improve feeding of liquid metal through the interdendritic mush. Various pouring temperatures and mould temperatures were adopted to achieve different solidification rate. The results show that, a lower cooling rate leads to less tendency to form porosity and better stability of rupture life at 700℃/620MPa. Through modification of the feeding system, the solidification sequence of the casting is changed and micro-porosity is effectively eliminated. Consequently, production yield in terms of the stress-rupture properties increases remarkably from 25% to 100%. On the other hand, the grain size increases and stress-rupture life at 700℃/620MPa gradually reduces with the decrease of the solidification rate. Compared with Inconel 718C, the modified alloy exhibits excellent tensile and stress-rupture properties at much higher temperature and stress.

关 键 词：铸造工艺 显微疏松 组织 力学性能 

分 类 号：TG27[金属学及工艺—铸造]