Ultrasonic Evaluation of Temper-Embrittlement for Martensitic Stainless Steel

Abstract

This research studied the possibility of non-destructive detection of temper-embrittlement in tempered CA-15 martensitic stainless steel (MSS). It was found that secondary hardening phenomenon existed in tempering temperature range of 573-673 K for the MSS in this study. Ultrasonic responses, both in terms of acoustic velocity and attenuation, exhibited changes with respective to the microstructure variation. Microstructural constituent of chromium carbide (Cr₂₃C₆ type) precipitates was found to have resulted in the temper-embrittlement of the MSS and also was responsible for the changes of the ultrasonic behavior of the material.