A method for predicting hot deformation resistance of STS 430 ferritic stainless steel

摘要

PURPOSE: A method for predicting deformation resistance that is an essential factor for calculating rolling load when hot rolling 430 ferritic stainless steel in which ferrite and austenite coexist in rolling region using tandem type finishing mills during the hot steel rolling process is provided. CONSTITUTION: The method comprises a step of experimentally obtaining influence of temperature and strain rate exerted on steady state flow stress (s) by the following mathematical expression 1 after experimentally reproducing a material having an austenite phase volume fraction that is the same as an input side work of first rolling mill in tandem type finishing mills: s=A1xln +A2/T+A3, where s is steady state flow stress (kg/mm¬2), is strain rate(1/sec), T is absolute temperature, and A1, A2 and A3 are constants; a step of obtaining deformation resistance (Km) of plane deformation by the following mathematical expression 2 using the steady state flow stress (s): Km=2¡î3x(A1xln +A2/T+A3), where Km is deformation resistance of plane deformation (kg/mm¬2); and a step of correcting experimental coefficients A1, A2 and A3 of the mathematical expression 2 using actual deformation resistance results of actual rolling.