Process integrated nondestructive testing (PINT) for evaluation of hardness, case depth and grinding defects

摘要

Up to now, techniques such as metallographic inspection, X-ray diffraction, and hardness measurements are used for the determination of material characteristics. However, these techniques cannot be integrated into the production line because their testing speed is too low and most of these techniques are destructive in nature. Since hardness and stress measurements are influenced by various material parameters, nondestructive multiparameter techniques are necessary to get unambiguous values. Macromagnetic (3MA) and Multifrequency Eddy Current (MFEC) techniques developed in recent years are found to be most appropriate for nondestructive multiparameter testing. Quantitative values can be achieved by using multiple regression or neural net analysis. Industrial applications have shown that PINT will be used, provided that: The results will be economically beneficial Conventional tests are not applicable Different material properties must be measured simultaneously Disturbances can be suppressed using probes with multiparameter characteristics Real-time monitoring systems and 100 percent inspection are needed Actual examples on Process Integrated Nondestructive Testing (PINT) are given on hardness, case depth and grinding defect measurements.