中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 5 May 2011 |
（1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Baosteel Research Institute, Baoshan Iron & Steel Co., Ltd., Shanghai 201900, China）
Abstract:Quantitative analysis was employed to establish reasonable and practical homogenization model of INCONEL718 superalloy. Metallographic method was applied to determining the incipient melting temperature. The result shows that the incipient melting temperature of d406 mm INCONEL718 ingot is situated between 1 170 °C and 1 180 °C. In order to predict the elimination process of Laves phase in quantity, a time and temperature dependent homogenization model was proposed. Among all the elements in the as-cast microstructure, Nb and Ti are the most positive segregated elements. The diffusion coefficients of alloying elements at 1 140 °C were obtained by fitting the linear relationship between ln δ (δ: residual segregation index) and time. The calculation results of diffusion coefficients were compared with other two commercial Nb-bearing superalloys.
Key words: INCONEL718; superalloy; homogenization; Laves phase; segregation
