On the damage of a work roll grade high speed steel by thermal cycling

The surface degradation experienced by a work roll grade high speed steel as result of high frequency thermal cycling was characterized by means of X-ray diffraction, light optical and scanning electron microscopy. It was found that the degradation mechanisms experienced by the steel under these conditions include oxidation, carbide cracking and spallation and, crack formation in the martensite matrix which also presents a decrease in hardness as the number of thermal cycles is increased. The development of these mechanisms and their impact on the life of high speed steel work rolls is discussed.

► We have developed a test methodology to understand the degradation mechanisms of work rolls in hot strip mills. ► Thermal cycling increases surface damage in work rolls by plastic deformation and oxidation. ► Processing of steel strip now takes into account roll degradation to develop more efficient rolling operations.