THERMAL TREATMENT OF STEEL SOLUBILISATION

Solubilisation is the heat treatment reserved for stainless and duplex steel (the solubilisation process is applied in slightly different ways to other non-ferrous metal alloys as aluminium-copper).
This heat treatment consists of a heating and maintenance phase at a high temperature (between 1050 °C and 1.200 °C, but more frequently between 1050 °C and 1100 °C) followed by rapid cooling with water (black finish that requires a further pickling treatment) or inert gases (bright finish), aimed at bringing back into solution (and therefore avoiding) the precipitates of chromium carbides, which would otherwise have the time to form in the case of slower cooling. Chromium carbides are typically responsible for inter-crystalline corrosion.