Continuous mfr. of steel prods. in hot-rolling mill train - has water-spray in train to control structure and surface scale

摘要

During hot-rolling, before the finished size is reached, the steel is cooled so its max. temp. on leaving the roll train of 954 degrees C. The process is esp. applicable to carbon steel billets contg. 0.95-1.1 wt.% C with the usual other elements and an initial rolling temp. of 1056-1149 degrees C., but other carbon and alloy steels may also be treated. The roll train consists of multiple stands divided into an initial stage, intermediate stage, and a finishing stage, water-spray cooling units being provided in the intermediate stage with synchronised use of rolling speed, temp., and vol. of water for optimum results. The finished hot-rolled steel has a uniformly fine grain with higher ductility and less burnt-on scale than is normally obtd.