A martensitically hardenable steel and process for its production

This invention relates to a martensite-hardenable steel with improved scrap-cutting machinability, good weldability and trigh corrosion-resistance, a process for heat-treatment of such a steel, and its application. According to this invention this steel contains, in percentage by weight: 0.02-0.075% carbon 0.1-0.6% silicon 0.5-0.9% manganese 0.08-0.25% sulfur maximal 0.04% phosphorus 12.4-15.2% chromium 0.05-1.0% molybdanium 0.2-1.8% nickle maximal 0.15% vanadium 0.1-0.45% copper maximal 0.03% alluminum 0.02-0.08% nitrogen as well as (if necessary) one or morel further alloy elements up to maximal 2.0%, the rest being iron and impurities related to the production, and has a ferrite ingredient in the texture of at least 28% by volume. A process for the heat-treatment of a martensite-hardnabe steel with improved scrap-cutting machinability, which process provide an object that hardens thoroughly even with big cross section, comprises substantially in that a steel block with the above composition is subject to an annealing treatment to form and to adjust a ferrite ingredient in the texture in a first step, and in a second step a heat deformation of the same is effected, afterwards in a third step a soft annealing and subsequently a thermal temper-hardening is performed.