METHOD FOR EVALUATING HARDENABILITY OF STEEL BY X-RAY DIFFRACTION

摘要

PURPOSE:To measure rapidly the hardenability of steel on a nondestructive basis by obtaining a diffraction line showing the relation between the diffraction angle and the intensity of X-rays, and measuring the sharpness of a peak from a Gaussian curve parameter closely resembling the peak. CONSTITUTION:The diffraction line showing the relation between the diffuraction angle and the intensity of X-rays is obtained by irradiating X-rays on hardened steel. The sharpness of the peak of a sharp diffraction line characteristic of incompletely hardened steel is measured by using the parameter of a Gaussian curve (a constant, hereinafter referred to as GCP) resembling closely the peak of the diffraction line. The GCP at this time is compared with the previously obtained GCP of completely hardened steel contg. the same amt. of C. The incompleteness of hardening or the area ratios of troostite structure and pearlite structure to martensite structue are thus measured. The completeness of hardening of steel or hardenability can be evaluated by this method on a nondestructive basis without depending on the measurement of hardness, etc.