Effect of compound jacketing rolling on microstructure and mechanical properties of superalloy GH4720Li

In this paper, a compound jacketed rolling technique for superalloy GH4720Li is experimentally investigated. The results show that microstructure of GH4720Li is susceptible to hot working parameters. When rolling temperature is about 1130ºC, a fine-grained microstructure, excellent mechanical properties and high yield strength can be obtained. In addition, the rolling temperature can be controlled effectively, friction force between ingot and roller can be reduced, surface cracking induced by rolling can be avoided, and uniform microstructure can be obtained using compound jacketing. When accumulative strain of rolling is greater than 65%, the coarse columnar dendritic microstructure can be refined completely and grain size of ASTM 8 obtained. After heat treatment, GH4720Li bars exhibit excellent mechanical properties. (AU) © 2010 by The Materials, Metals, & Materials Society. All rights reserved.