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 of being manufactured easily in a general hot strip mill, and having a low mechanical anisotropy and, moreover, final hyperfine particles of ferrite of less than 2 .mu.m which could not be attained by conventional techniques; and a method of manufacturing the same. This hot rolled steel plate contains ferrite as a main phase, and has an average ferrite particle size of less than 2 .mu.m and an aspect ratio of the same of less than 1.5, the hot rolled steel plate being obtained by carrying out the draft of the steel plate in a dynamic recrystallization zone in a draft path of not less than five stands during a finishing hot rolling operation.