Effect of aging temperature on the microstructural evolution and mechanical properties of 18Ni (200) maraging steel

Abstract

Herein, we used transmission electron microscopy (TEM), electron backscattering diffraction (EBSD), and X-ray diffractometry (XRD) to investigate the effects of different aging temperatures on reversed austenite and precipitates in 18Ni (200) maraging steel, as well as their evolving patterns of cryogenic toughness and strength. Aging at 510 °C was found to enhance cryogenic toughness at −196 °C and deliver peak strength, which is attributable to the significant aging-strengthening effect and the reversed austenite. Furthermore, this study investigated the factors that contribute to the formation and high stability of reversed austenite and quantitatively assessed the contributions of aging strengthening, dislocation strengthening, and grain-boundary strengthening to yield strength at various aging temperatures.