HOT-ROLLED STEEL FOR HOT FORMING Russian patent published in 2016 - IPC C22C38/54 C22C38/58 

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, specifically to structural hot rolled steel, intended for production of high-strength steel complex-shape parts by hot forming, including vehicle structural elements. Said steel contains following substances, wt%: carbon 0.08-0.3, silicon 0.20-1.0, manganese 0.60-2.0, chrome 0.60-1.80, nickel 0.02-0.8, molybdenum 0.001-0.30, titanium 0.02-0.08, vanadium 0.002-0.08, niobium 0.038-0.07, boron 0.0001-0.004, copper 0.05-0.20, aluminium 0.01-0.09, nitrogen 0.006-0.015, phosphorus ≤ 0.03, sulphur ≤0.015, iron and unavoidable impurities, including hydrogen ≤ 0.0004, balance. Steel has uniform dispersed ferrite-pearlite structure with number of ferrite grain 9-11, and content of titanium and nitrogen, niobium and carbon linked by relationships: 2.0 ≤ [Ti]/[N] ≤ 5.5 and 0.003 ≤ [Nb]·[C] ≤ 0.012.

EFFECT: high strength after hot forming.

1 cl, 2 tbl