METHOD OF PRODUCING STEEL SECTIONS OF IMPROVED QUALITY

摘要

A steel section 6 to 40 mm thick, emerging from a hot rolling mill at 1000 to 800.degree.C is surface quenched for 2 to 6 seconds at a cooling rate of the order of 1.5 to 5 MW(megawatts)/m2. During subsequent self-tempering of the quenched surface by heat from the remainder, the section tends to an equalization temperature of 500 to 700.degree.C.