Examination of surface defects induced during hot rolling of high-alloy steel bar and rod

Abstract

The authors examine three problems associated with the production of high-alloy steel bar and rod by rolling in hand-operated mills. An outline is given of the mechanics of formation of surface defects and, by using a model material for hot steel (Plasticine) as well as three grades of steel, the defects were examined. Although the work was carried out using hand-operated mills, the conclusions drawn are relevant to commercial continuous mills for producing low-alloy and carbon steel rod and bar. The defects examined were cracking, split ends, and decarburization. The main conclusion is that careful selection of pass sequence, taking into account all the manufacturing and product requirements, is essential in order to control the rate of rejection of rod and bar with these defects