Increasing Roll Life for Steel Rolling Processes

摘要

Research has been conducted to investigate the roll cooling system used in steel rolling mills and its relationship to roll life. Special laboratory apparatus to resemble the cooling systems used in the steel mill has been developed to evaluate the corresponding heat transfer coefficients. An understanding of the cyclic thermal behavior can be used to evaluate roll wear and leads to reduce the roll spalling or extend the roll life by minimizing the cyclic stress or the resultant fatigue stress. To minimize the cyclic or fatigue stresses, the roll should be subjected to uniform cooling. The sharper the heat transfer coefficient distribution, the higher the thermal stress induced. In the hot rolling condition, the roll cooling design and arrangement have a tremendous influence on the thermal stress and thermal expansion patterns. The present study concluded that the cooling arrangement, common in British steel mills, of the water jets located in the regions immediately before the entry or after the exit of the strip is not desirable.