An integrated approach to analysis and assessment of condition parameters of the surface layer of backup roll bodies of a continuous broad-strip hot rolling mill

Abstract

This study presents the outcomes of applying an integrated approach for assessing surface layer parameters of backup roll bodies in the continuous broad-strip hot rolling mill 2000 at Severstal. This approach includes several key aspects: the operational intensity of backup rolls, the increase in body hardness, wear across different stands in the continuous mill, and the determination of the material removed after the rolling campaign. To estimate the operational intensity of backup rolls within the mill stand during the campaign, the methodology suggests using the number of contacts with the working roll or the total length of strips rolled in each stand, alongside the linear load exerted on the rolls during inter-roll contact. Experimental findings have revealed that backup roll bodies exhibit varying degrees of wear and hardness increases across the continuous mill stands throughout the rolling process. The strip length and linear load in the stands have been determined to be crucial factors influencing the wear and hardness increase of backup roll bodies during a campaign. The research successfully derived a formula to illustrate how the length of rolled strips and the inter-roll load affect the increment of the roll bodies. Furthermore, an algorithm for predicting wear in three zones along the mill stands with a prediction accuracy of at least 85% was developed. The study proposes a method for calculating the necessary removal during backup roll grinding based on up-to-date data from the mill for the duration of the rolling campaign, which correlates with the roll’s operational intensity in the stand. The proposed solution aims to optimize roll consumption significantly.

Implementing this integrated approach to assess the condition of backup roll bodies, particularly within the context of the 2000 hot rolling mill at Severstal, satisfies the evolving requirements for roll operation. Additionally, it aligns with the new requirements for compiling a rolling schedule, ultimately enhancing mill productivity.