AUSTENITE CORROSION RESISTANT STEEL FOR CHLORIDE CONTAINING MEDIUMS AND ITEM MADE OUT OF IT Russian patent published in 2011 - IPC C22C38/58 C22C38/54 

FIELD: metallurgy.

SUBSTANCE: steel contains carbon, silicon, chromium. nickel, manganese, nitrogen, copper, boron, molybdenum, hafnium, iron and unavoidable impurities at following ratio of components, wt %: carbon ≤ 0.02, manganese 1.0 - 2.0, silicon ≤ 0.8, chromium 16.0 - 18.0, nickel 8.0 - 9.5, molybdenum 2.5 - 4.0, nitrogen 0.10 - 0.20, copper 0.3 - 0.9, boron 0.001 - 0.005, hafnium 0.001 - 0.01, iron and unavoidable impurities - the rest. Contents of molybdenum, boron and hafnium is determined with dependence (B + Hf) · (5Mo) = 0.035 - 0.25. Hot rolled sheets of 3-10 mm thickness and cold rolled sheets of 0.8-3.0 mm thickness are made out of steel.

EFFECT: increased qualitative service life of weld items due to high corrosion resistance to pitting and corrosion under voltage in chlorine containing mediums at high temperature combined with raised durability and sufficient processability at hot and cold forming operations.

4 cl, 3 dwg, 4 tbl, 1 ex