Homogeneity of Electroslag Remelting Microstructure of Superalloy Inconel 718,Inconel 706 and Inconel 706M
Author of the article:WANG Lu;XIAO Zhixia;ZHAO Lin;BAI Yaguan;YIN Fuxing
Author's Workplace：School of Materials Science and Engineer,Hebei University of Technology,Tianjin 300130,China;Research Institute for Energy Equipment Materials,Hebei University of Technology,Tianjin 300130,China;Iron and Steel Research Institute,Beijing 100081,China;Tianjin Heavy Equipment Engineering Research Co.,Ltd.,Tianjin 300301,China
Key Words：electroslag remelting superalloy microstructure segregation homogeneity
Abstract：The dendrite structure and precipitation phase differences of electroslag remelting ingot of Inconel 718, Inconel706 and Inconel 706M were studied. The results show that among the three kinds of superalloys, the difference between the dendrite spacing in the center of 718 ingots and the edge is the smallest, and the difference between the segregation rate of the main segregation elements Nb and Ti in the center of 718 ingots and the edge region is the smallest, and the macroscopic microstructure uniformity of 718 ingots is the best. The dendrite spacing difference between the center and the edge of 706M ingots is the largest, and the difference between the Nb element segregation rate in the center of the ingots and the edge is 0.91%. The microstructure uniformity of the ingots is the worst. 718 ingot dendrites are prone to enrich positive segregation elements Nb and Mo, with the highest contents reaching 6.82% and 3.01%, respectively. The highest Nb content between dendrites of 706 and 706M ingots is less than 4%, and the highest Ti element content is more than 2%. Meanwhile, the Nb segregation rate in the microstructure of 706 and 706M ingots is still very high. The phase of Laves in 706 ingot structure is the most, and the phase content of Laves in the center reach 3.9%, and the edge content decrease by more than 2%, with uneven distribution. 706M Laves phase is the least in the cast ingot structure, and the content in the center and edge is less than 2%. The content distribution is relatively uniform. Compared with 718 and 706,the average length of carbonitrides in the central region of 706M ingots varied the most from the edge, and there are fewer acicular phases in the microstructure.
