| 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: An method for evaluating cracking in a thin plate comprises: a step of obtaining by experiment, "experimental data" which are values of critical strains &egr;at different strain ratios &rgr;(j=1 to J) in such conditions that predetermined temperatures T(i=1 to I)(°C) are constant; a step of classifying for each strain ratios &rgr;(j=1 to J), "the experimental data" into J pieces of groups comprised of I pieces of data of the temperatures Tand the critical strains &egr;and obtaining curves which satisfy I pieces of data for each group; a step of obtaining "warm FLD data" comprised of the strain ratios &rgr;and critical strains &egr;corresponding to temperatures T(°C)(k=1 to K) predetermined separately from the above predetermined temperatures with respect to the above respective curves; and a step of making warm FLD comprised of the maximum strain &egr;, the minimum strain &egr;and temperature T(°C), based on "the warm FLD data". |
