The Inconel 718 superalloy is extensively used to manufacture critical parts in aeronautical, astronautical, oil and chemical industries due to its excellent mechanical, physical and anti–corrosion behavior. Usually, these parts are shaped by hot forging or rolling in open–train mills.
Recently, the tandem hot rolling has been applied to form superalloy bar products. In some cases, it can replace the traditional rolling, since it has higher productivity and product quality. In order to obtain the most favorable microstructure and the best mechanical properties of Inconel 718 alloy in
tandem hot rolling, it is necessary to control its microstructural evolution in every step of the whole rolling process. With the aid of computer modeling, it is possible to make such a controlling process possible. As the first step in tandem hot rolling, reheating process of a forged slab prior to rough
rolling plays a predominant role in predicting the grain size change or even the microstructural evolution. Thus, in this study, an Inconel 718 alloy forged slab was used as the experimental material and the effects of reheating temperature and holding time on its grain growth were investigated. A
universal model was developed and verified for the grain growth of Inconel 718 alloy forged slab in reheating process prior to rough rolling. With the increase of holding time, the grain size shows no remarkable change up to 1173 K. The grain growth presents a linear trend in the range from 1173 to
1323 K. A parabolic trend of gain growth can be observed when reheating temperature is higher than 1323 KThe established grain growth model of Inconel 718 alloy would be suitable to calculate the grn size evolution under the both isothermal and non–isothermal reheating conditions. This could also provide a basis in formulating the technological parameters for tandem hot rolling of Inconel 718 superalloy.