(1. 中北大学 材料科学与工程学院,太原 030051;
2. 河北工业职业技术学院 机电工程系,石家庄 050091;
3. 扬州峰明金属制品有限公司,扬州 225117)
摘 要: 采用CAFE模型(Cellular automata finite element method)模拟第二代镍基高温合金CMSX4凝固过程中的晶粒生长,并探讨浇注温度和冷却速度对凝固组织的影响。结果表明:凝固开始时,首先在铸锭底部会形成一层取向随机的细小等轴晶,由于晶粒间的竞争生长,晶粒数目减小,晶粒尺寸增大,á001?晶向与热流方向偏离角较大的晶粒逐渐被偏离角较小的晶粒淘汰。浇注温度的提高会使晶粒尺寸变大、晶粒数目变小,而冷却速度的升高却会使晶粒尺寸变小,与理论分析一致。
关键字: 镍基合金;CMSX4合金;CAFE法;定向凝固;组织演化
(1. College of Materials Science and Engineering, North University of China, Taiyuan 030051, China;
2. Department of Electrical Engineering, Hebei College of Industry and Technology, Shijiazhuang 050091, China;
3. Yangzhou Feng Ming Metal Products Company Limited, Yangzhou 225117, China)
Abstract:CAFE model was adopted to simulate the grain growth during solidification process of the second generation nickel-based superalloy CMSX4, and then the influences of casting temperature and cooling rate on the solidification structure were discussed. The results show that at the beginning of solidification, a layer of fine equiaxed grains with random orientation forms first. Due to the competition between the grain growth, the number of grains decreases, the grain size increases, and the grains with bigger deviation angle of the á001? crystal orientation deviating from the direction of heat flow are gradually eliminated by the grains with small deviation angle. The increase of pouring temperature will make the grain size bigger, the number of crystal grains decreases, while the increase of cooling rate can make the grain size smaller. The results are consistent with the theoretical analysis.
Key words: nickel-based alloy; CMSX4 alloy; CAFE method; directional solidification; structure evolution