Influence of Forging Temperature on Ultrasonic Properties of GH4738 Alloy Microstructure based on Ultrasonic C-scanning

Rapid measurement of ultrasonic characteristic parameters related to microstructure is the key for studying the influence of hot forging process on the microstructure of super alloy and its ultrasonic nondestructive evaluation. In this paper, the ultrasonic longitudinal wave velocity and attenuation coefficient of 4738 superalloy with different forging temperature were measured automatically by using water immersion ultrasonic testing system and high-efficiency ultrasonic C-scan method, and the influence of forging temperature on the ultrasonic properties of alloy microstructure was analyzed. The results show that the good linear correlation can be observed between forging temperature and velocity and attenuation coefficient, which can objectively reflect the effect of forging temperature on the ultrasonic properties of microstructure. The C-scan images based on different ultrasonic characteristic parameters are helpful to show the difference of material structure in different regions, and provide auxiliary means for the screening of heat treatment microstructure and the establishment of hot forging process for a large number of GH4738 raw materials.