GCr15钢显微组织的超声无损表征研究

ake the widely used steel GCr15 as the samples material, PXUT-280 intelligent digital ultrasonic flaw detector as the basic ultrasonic analytical tool combined with the ordinary and narrow pulse P-wave ultrasonic transducer with the frequency of 1MHz, 2.5 MHz, 5 MHz, 10 MHz, the ultrasonic testing system is set up. Two sets of cylindrical samples with different height (20mm and 40mm) are designed and processed. Through the heat treatment processing of annealing, quenching, quenching plus low temperature tempering, quenching plus high temperature tempering, four typical microstructures are obtained. The ultrasonic velocity and attenuation of the samples are tested by using transducers with different frequency and sound beams, and the microstructure of different samples is analyzed by using S-3400 SEM. The relationships between velocity and microstructure, attenuation and microstructure of steel GCr15 are analyzed and set up. In this dissertation, the influence of surface quality on ultrasonic testing is experimentally studied too.