Experimental and numerical modeling of flatness defects in strip cold rolling

Abstract

a b s t r a c tThe manufacturing of sheets with high mechanical yield stress, low thickness and minimal flatness defects is a major challenge in the cold rolling of aluminum alloys or steels. Compressive residual stress may appear due to the manufacturing process and induce elastic wave buckling, leading to flatness defects. This study proposes an experimental setup to analyze the interaction between residual stress and buckling for wavy edge flatness defects. The residual stress is simulated by thermal stress. High-resolution full-field measurements are used to measure the wrinkling shape and thermal field. The influence of surface imperfections and global tension on the wrinkling characteristics is highlighted. Finite element tests are used for test validation.

A New Curvature Analytical Method in Plate Leveling Process

“…Zhifang LIU, 1) * Yuanxin LUO, 2) Yongqin WANG 2) and Thunshun Warren LIAO 3) 1) College of Mechanical Engineering, Chongqing University of Technology, Chongqing, 400054 China.…”

“…However, conventional plate rolling process, cooling transformation, improper placement during transport and non-uniformity distribution of residual in-plane normal stress along the thickness direction often yields some defects including curl, gutter, middle waves and edge waves. 1) To ensure effective correction of the aforementioned defects and quality improvement in the production of plates, the leveling process must be properly designed to reduce these defects before it goes to the secondary manufacturing process.…”

Multi-Objective Optimization of Intermediate Roll Profile for a 6-High Cold Rolling Mill

“…Strip thickness control accuracy has been very high with the development of automatic gauge control (AGC). Hence, the flatness control problem becomes more and more prominent [1,2]. The flatness of the strip is directly affected by the loaded roll gap profile.…”

“…A continuous, gradual adjustment of roll gap profile is achieved by the continuous axial shifting. SmartCrown roll profile can be described as Equation (2) and Equation 3. The rolls have a deflection under the action of rolling force, which can be compensated by designing an original roll profile as a parabola.…”

Analytical solution for nonlinear vertical vibration model of mill roll system based on improved complexification averaging method

“…And the operational reliability of MRS is the key to guarantee the rolling process with high precision, high speed, continuity and stability [1]. In steady rolling process, the force balance relation will be destroyed when MRS is disturbed by interference force, and the vertical vibration will be produced [2,3]. The vertical vibration of MRS has a significant effect on rolling precision and product quality.…”