Alleviation of high-temperature oxidation and cracking of water-cooled roll for hot-rolling steel

Abstract

Hot rolling is performed inside a heating furnace where the material is heated above its recrystallization temperature. As pinch rolls are located in this furnace and subjected to continuous high temperature, they are typically cooled with water to protect them from the harmful effects of the high atmospheric temperature. Despite cooling, cracks can develop on the surface of water-cooled rolls, which can result in fracture over time; further, high-temperature oxidation can cause the metal strip to stick to the roll, resulting in defects on the strip surface. To address these problems, we analyzed pinch rolls through mechanical stress, thermal stress, and high-temperature oxidation investigations with data measured from a production line in situ. Subsequently, solutions for improving the performance of the pinch rolls predicted from the calculations were applied to an actual hot rolling process.