Spinodal decomposition mechanism study on the duplex stainless steel UNS S31803 using ultrasonic speed measurements

This work, focuses on the spinodal decomposition mechanism study on the duplex stainless steel duplex UNS S31803, composed by austenite (γ) and ferrite (α) phases, at 425 °C and 475 °C temperatures by ultrasonic speed measurements. This temperature range is responsible for the transformation mechanism of αinitial phase to α phases (poor in chromium) and α′ (rich in chromium) by spinodal decomposition. The techniques to accomplish this analysis are based mainly on X-ray diffraction measures and ultrasonic speed. The obtained results show that it is possible to conclude that the use of ultrasonic speed measurements indicates a promising technique for following-up the phase transformation and spinodal decomposition on the steel studied.