6. Heat treatment

Heat treatments give stainless steels the properties they need for their intended use, mainly mechanical properties (ductility, toughness and hardness) and corrosion resistance. Heat treatments are specific to each family of stainless steels.

• For martensitic stainless steels, they are given in the article (cf. , paragraph 2.3). High hardness and good corrosion resistance are the main requirements for these grades.

• For ferritic stainless steels, a distinction must be made between those that remain ferritic throughout the temperature range and those that are semi-ferritic, forming up to 30% austenite when hot, the latter transforming into martensite on cooling. What's more, for unstabilized or semi-ferritic grades, any holding at temperatures between 900 and 950 C followed...