STEEL OF HIGH MECHANICAL STRENGTH AND WEAR RESISTANCE Russian patent published in 2009 - IPC C22C38/60 C22C38/58 C22C38/54 C22C38/50 C21D8/00 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, particularly to high strength wear resistant steel and to method of its fabrication. Melt of liquid steel is produced by melting elements excluding titanium and/or zirconium. Titanium and/or zirconium are introduced into melt eliminating their local concentration at any given moment; steel is produced containing elements at the following ratio, wt %: carbon 0.35 - 1.47, silicon 0.05 - 1.5, manganese ≤ 1.95, nickel ≤ 2.9, chromium 1.1 - 7.9; molybdenum 0 - 4.29; tungsten 0.21 - 4.9, titanium 0 - 1.49, zirconium 0 - 2.9, if necessary, one or several elements chosen from a group: vanadium ≤ 1.45, niobium ≤ 1.45, tantalum ≤ 1.45, boron up to 0.1, sulphur up to 0.19, selenium up to 0.38, tellurium up to 0.76, calcium up to 0.01, rare earth elements up to 0.5, aluminium up to 1.0, copper up to 1.0, iron and additives introduced during melting - the rest. The following ratios are maintained for composition of steel: 0,61 ≤ Mo + W/2 ≤ 4.4, 0.21 ≤ Ti + Zr/2 ≤ 1.49, V + Nb/2 + Ta/4 ≤ 1.45, S + Se/2 + Te/4 ≤ 0.19, (Ti + Zr/2) / W ≥ 0.20, (Ti + Zr/2) × C ≥ 0.07, 0.3 ≤ C* ≤ 1.42, 800 ≤ D ≤ 1150, where D is index of hardness upon dispersion hardening at tempering determined by expression: D = 540(C*)^0.25 + 245(Mo + W/2 + 3V + 1.5Nb + 0.75Ta)^0.3 + 125Cr^0.20 + 15.8Mn + 7.4Ni + 18Si, and C* is contents of carbon not bound into primary carbides of titanium and/or zirconium determined by expression: C* = C - Ti/4 -Zr/8. Steel is tapped for production of semi-product, subject to hot plastic deformation and, if necessary, to heat treating.

EFFECT: producing steel of upgraded complex of mechanical properties, improved cutability, weldability and resistance to impacts and bending loads.

15 cl, 1 dwg, 4 tbl