METHOD AND APPARATUS FOR PRODUCING MARTENSITE- OR BAINITE-RICH STEEL USING STECKEL MILL AND CONTROLLED COOLING

摘要

A steel rolling mill including a Steckel mill (19) is provided with an in-li ne upstream quench station (14) located downstream of the caster (11) and upstream of the reheat furnace (15), a shear (25) located downstream of the Steckel mill (19), and a temperature reduction station downstream of the she ar (27, 28). The upstream quench station (14) has spray nozzles that quench a surface layer of the steel to transform same from an austentitic to a non- austentitic microstructure. The shear (25) provides a precise transverse vertical face on the leading end of the steel. The temperature reduction (27 , 28) station applies cooling fluid to the rolled steel so as to obtain a preferred microstructure that may be either bainite or martensite. If bainit e, the temperature reduction station includes laminar-flow cooling apparatus; i f martensite, the station also includes an initial rapid quench (28), in which latter case the station is followed by a tempering furnace (37).