HSS rolls have excellent wear resistance, and their service life in the finishing stand of hot mill is 3~6 times that of high chromium iron rolls. Uneven temperature distribution on the roll surface of HSS rolls will easily produce uneven thermal expansion, resulting in oxide film shedding and affecting the surface quality of products. By optimizing the cooling water configuration of HSS rolls, the cooling water in the middle part of the roll body is increased to ensure uniform temperature distribution.
Hot rolling process lubrication system can bring a protective film covering the surface of HSS rolls, reducing rolling force and keeping roll surface at good condition, while also preventing iron oxide to affect surface quality. In order to ensure the lubrication effect, it is necessary to steam clean the total pipeline of lubrication regularly.
Working times of the rolls between two grinding rolls are mainly determined by the oxide film form on the roll surface, roughness value and the grade of the rolled material after getting off the machine. In addition also with whether close to the finishing stand, in the oxide film and roughness state are in good condition, the rolls of the upstream stand often can be used more times than the rolls of the downstream.
During rolling process, if the rolling mill working abnormally, that could cause serious local mesh thermal cracking of the roll surface, the HSS roll should be replaced immediately. Roll surface crack detection should be carried out by automatic or portable ultrasonic flaw detector after the rolls are cooled.
