Martensitic stainless steel with improved machinability.

摘要

Martensitic stainless steel with improved machinability, characterised in that its composition by weight is the following: - carbon lower than 1.2 % - silicon lower than or equal to 2 % - manganese lower than or equal to 2 % - chromium: 10.5 < Cr < 19 % - sulphur lower than or equal to 0.55 % - calcium higher than 32 x 10<-4> % - oxygen higher than 70 x 10<-4> %, - the ratio of the calcium and oxygen contents Ca/O being 0.2 < Ca/O < 0.6, the said steel being subjected to at least one quenching heat treatment in order to give it a martensitic structure.