Non-destructive estimation method for toughness

摘要

PURPOSE:To evaluate toughness accurately in a nondestructive manner by using a quenching speed, temper hardness and quenching temperature as parameters and by using a function of the amounts of these parameters. CONSTITUTION:A quenching speed (CR), temper hardness (H) and quenching temperature (T) are used as parameters, and the toughness (Ch) of a material is estimated as a function [Ch=f(CR, H, T)] of the amounts of these parameters. As for the material to be applied, SKD5, SKD6, SKD61, SKD62, SKD7, SKD8, etc., are mentioned and the material of which the state of the heat-treated texture is affected by the quenching speed is an object. The quenching temperature (T) is measured by measuring an inner-furnace atmosphere temperature by a thermo-couple, for instance, for the purpose of evaluating the austenitized state of the material. By measuring the hardness, the quenching temperature and the quenching speed with the relationship of the amounts (Ch, H, T, CR) determined beforehand, the toughness can be estimated in a nondestructive manner.