HIGH-STRENGTH CORROSION-RESISTANT STEEL Russian patent published in 2008 - IPC C22C38/48 

FIELD: ferrous metallurgy industry; mechanical engineering industry; shipbuilding industry; production of the high-strength corrosion-resistant steels.

SUBSTANCE: the invention is pertaining to the steel metallurgy, in particular, to the field of production of the high-strength corrosion-resistant alloyed steels used for production of the high-loaded details in the mechanical engineering industry and shipbuilding. The invention presents the steel containing(in mass %): carbon - 0.04-0.07, silicon - no more than 0.6, chromium - 15.5-16.5, nickel - 4.8-5.8, nitrogen - 0.11-0.18, niobium - 0.03-0.08, vanadium - 0.03-0.08, manganese - 0.5-1.0, calcium - 0.02-0.03, iron and the imminent impurities - the rest; at fulfillment of the following conditions: ([V]+[Nb])/([C]+ [N])= 0.4÷0.6 and [Cr]-l.5[Ni]+2[Si]-0.75[Mn]- 30[C+N]+l.5[V]+0.9[Nb]= l÷4. After the tempering and-or the plastic deformation with the subsequent cold treatment, tempering or the cold plastic deformation the steel has the fine-grain structure with the grain size of 15-25 microns and content of the martensite of 75-90 % and the austenite - of 25-10 %. The invention allows to attain the improved strength at conservation of the satisfactory pliability, that ensures the increase of the operational reliability and the service life of constructions made out of this steel at their operation.

EFFECT: the invention ensures the improved strength at conservation of the satisfactory pliability, the increased operational reliability and the service life of constructions made out of this steel at their operation.

5 cl, 2 tbl