HOT ROLLED STEEL SHEET HAVING ULTRA FINE GRAINS WITH IMPROVED FORMABILITY, AND PRODUCTION OF HOT ROLLED OR COLD ROLLED STEEL SHEET

摘要

A hot rolled steel plate to be processed capable ofbeing manufactured easily in a general hot strip mill, andhaving a low mechanical anisotropy and, moreover, finalhyperfine particles of ferrite of less than 2 µm which couldnot be attained by conventional techniques; and a method ofmanufacturing the same. This hot rolled steel plate containsferrite as a main phase, and has an average ferrite particlesize of less than 2 µm and an aspect ratio of the same of lessthan 1.5, the hot rolled steel plate being obtained bycarrying out the draft of the steel plate in a dynamicrecrystallization zone in a draft path of not less than fivestands during a finishing hot rolling operation.