Cooling of hot rolled steel stock

Abstract

This invention relates to a method of cooling hot rolled coiled bar in which the bar is water-cooled immediately after rolling to a temperature (t.sub.1 ') at which it is still sufficiently ductile to be readily coiled, in which it is then forced air cooled to a temperature (t.sub.1) not less than that at which transformation of the body of the bar from austenite begins, in which it is then free air cooled to a temperature (t.sub.2) not less than that at which scale transformation from wustite begins and in which the coiled bar is finally water-cooled to quench-in and suppress the transformation of the scale to magnetite. Typical temperature ranges for mild steel, low/high carbon steels (up to 1%C), low alloy steels and semi/free-cutting steels would be t.sub.1 ' 830.degree.C - 900.degree.C, t.sub.1 700.degree.C - 750.degree.C, t.sub.2 480.degree.C - 550.degree.C.

Dependencies are inferred from the claim text.