Rolling Mills Rolls

Rolling Mills Rolls Rolling had assumed importance in the industrialized world during the nineteenth century. Profiles and flats are hot rolled while some flat products are also cold rolled. Rolls are tools in the rolling mill. The weight of the rolls can vary from a few kilograms to as high as 250 tons. Rolls are required to carry out the heavy work of reduction of the cross section of the steel being rolled.  Rolls have to take all kind of stresses, loads from normal and abnormal rolling and which are changing with the roll wear during a rolling campaign. Roll should never break, spall or wear. They are expected to give excellent performance without causing any problems. Under the conditions of rolling, the contact area of the roll that comes in contact with the steel suffers wear, while other parts of the roll body and roll necks does not experience plastic deformation or fatigue but are under high loads. In the recent past rolling technology was improved and changed but rolls have always remained the critical part of the rolling mills. Hence the development of roll quality and roll making technology had followed the development of rolling technology. Historical developments In the nineteenth century basically non alloy grey iron and forged steel was used for rolls. The cast iron grades varied from mild hard to clear chill, where the barrel showed a white iron layer with grey iron core and necks. These rolls were used for flat rolling without any roll cooling in the sheet mills. Later cast steel rolls were developed. These rolls are still produced today. Around 1930 ICDP (Indefinite chill double pour) rolls were developed for hot rolling. In late 1990s ICDP enhanced with carbide rolls were developed. Around 1950 nodular...