METHOD FOR EVALUATING CRACKING IN THIN PLATE

摘要

PROBLEM TO BE SOLVED: To perform estimation of cracking in a thin plate considering the temperature at which breaking strain becomes maximum due to an influence of strain-induced martensitic transformation of austenite (γ) during being worked, of steel material containing the austenite (γ).SOLUTION: A method for evaluating cracking in a thin plate comprises: a step of collecting data of breaking strains &egr;upon normal temperature Twith respect to a plurality of strain ratios &rgr; for predetermined material and making a function which calculates the breaking strain &egr;upon normal temperature at an arbitrary strain ratio &rgr;; a step of respectively collecting a plurality of data of temperature T and breaking strain &egr;with respect to a plurality of strain ratios &rgr;; a step of making curves which satisfy the plurality of data of temperature T and breaking strain &egr;for each strain ratio &rgr;; a step of fitting one-variable symmetrical function to any one of the plurality of curves; and a step of making warm FLD based on the one-variable symmetrical function.