TWO-LAYER CORROSION-RESISTANT SHEET STEEL AND ARTICLE MADE FROM THIS STEEL Russian patent published in 2003 - IPC

FIELD: metallurgy; equipment working in aggressive media under pressure and at high temperatures; oil refining, chemical and other industries. SUBSTANCE: proposed sheet steel consists of main and cladding layers. Components of main layer are contained at the following relationship, mass-%: carbon, 0.05-020; silicon, 0.10-0.40; manganese, 0.- 0.7; phosphorus, no more than 0.025; sulfur, no more than 0.020; chromium, 0.9-2.5; molybdenum, 0.2-1.0; the remainder being iron and unavoidable admixtures. Minimum permissible content of carbon contained in steel of main layer depends on its thickness in finished state in accordance with the following expression: C_min = 0,0007H_m.l+0,053, where H_m.l is thickness of main layer in finished sheet, mm. Cohesive strength of layers is not below strength of main layer and content of sulfur of steel of cladding layer does not exceed 0.007 mass-%. Article is made from said two-layer corrosion-resistance sheet steel. Cladding layer has the following composition, mass-%: carbon, 0.05- 0.12; silicon, 0.2-08; manganese, 0.4-2.5; phosphorus, no more than 0.040; sulfur, no more than o. oo7; chromium, 14-20; nickel, 7-12; niobium, no more than 1.5. Minimum permissible content of niobium depends on content of carbon in accordance with the following expression: (Nb) = 7.5C. EFFECT: enhanced strength of steel; enhanced corrosion resistance; facilitated procedure; enhanced reliability. 3 cl, 1 tbl, 1 ex