Effect of first tempering temperature on the amount of reversed and retained austenite in Virgo 38, a 16Cr-4Ni low-carbon super-martensitic stainless steel

摘要

Within this work, the influence of the tempering treatments on the microstructure of a 16Cr-4Ni low-carbon supermartensitic stainless steel (SMSS) was studied. The work was focused on the determination of the presence and the amount of reverted austenite (austenite formed during tempering) and of retained austenite (austenite stable at room temperature). Different samples, initially coming from the same ingot, were treated in order to obtain different retained austenite contents. Microstructures obtained were hydrogen charged by cathodic polarization in NaCl solution. The amount of hydrogen trapped in these microstructures was measured by high temperature outgassing using thermal desorption spectroscopy, and was correlated to the amount of retained austenite measured by X-ray diffraction (XRD).