STRENGTHENING MECHANISM OF 15-5PH STAINLESS STEEL UNDER DIFFERENT AGING TEMPERATURES

Abstract

The research described here was aimed at illuminating the variation in the strengthening mechanism of Cr15Ni5 precipitation hardening stainless steel (15-5PH stainless steel) processed at aging temperatures ranging from 440–610 °C. The variation in the tensile property corresponding to different aging processes was measured, and the microstructure features were further characterized using a transmission electron microscope (TEM) and electron back-scatter diffraction (EBSD). Results indicated that the strength contribution induced by grain-refinement strengthening, precipitation strengthening and dislocation strengthening corresponding to different aging temperatures varying from 470–610 °C were determined to be distributed in strength ranges of 296–345 MPa, 0–469 MPa and 97–803 MPa, respectively. The strength increments caused by different combinations of precipitation strengthening and dislocation strengthening were crucial for determining the final mechanical properties of the studied 15-5PH stainless steel.