Development of Hot Rolling Run-out Table Roller with Fe-Cr-V-C Alloyed Cast Steel by Continuous Pouring Process for Cladding

Abstract

  In the hot strip mill of the steel manufacturing process, the run-out table roller transports the steel sheet and coil at high speed between the finishing rolling mills and down coiler machines. For this reason, the roller is required to withstand contact with the rolled product in high temperature in a water-cooled environment. Fe-Cr-V-C alloyed cast steels were developed and systematic investigation of material properties and functions was carried out. The metallurgical structure consisted of M₇C₃ carbide, dispersed granular MC carbide and matrix. This material has superior corrosion resistance, abrasion resistance, thermal crack resistance and seizure resistance. Cr forms M₇C₃ type carbide and V forms MC type carbide with high-hardness respectively, and they are partially dissolved in the matrix. The amount of carbide is increased with the increase in C, Cr and V contents of the carbide forming element to improve wear resistance. Corrosion resistance improves with increasing (Cr + Ni + Mo) / C value. Using this material as a shell material combined with the steel inner base material, a composite sleeve was made by the continuous pouring process for cladding, and this composite sleeve was used for the actual rolling operation. As a result, improvement of the durability of this roll was confirmed.