MANUFACTURE OF HOT ROLLED STEEL PLATE HAVING EXCELLENT SCALE ADHESION

摘要

PURPOSE:To manufacture the title steel plate having excellent scale adhesion and capable of working and coating as it is by subjecting a specific C-contg. steel material to hot rolling into a specific edge drop, coiling it at a specific temp. and thereafter subjecting the material to specific reheating treatment. CONSTITUTION:A steel contg. =20wt.% C is subjected to hot rolling in such a manner that the edge drop from the point of 125mm from the edge part in the plate width direction to the point of 25mm is regulated to =15mum. The hot rolled steel plate is coiled at =600 deg.C. After that, the steel plate is reheated to 600 to 700 deg.C in a nonoxidizing atmosphere of inert gas such as N2 and Ar and is soaked for 2 to 10hr. The steel plate is then cooled at =50 deg.C/hr cooling speed. By this method, the hot rolled steel plate having excellent scale adhesion and capable of working and coating without subjected to descaling by pickling can be obtd.