STAINLESS MARTENSITIC STEEL FOR MOULDS AND FRAMES OF MOULDS FOR CASTING UNDER PRESSURE Russian patent published in 2010 - IPC B29C33/38 B29C45/26 C22C38/60 C22C38/58 C22C38/50 

FIELD: metallurgy.

SUBSTANCE: steel contains components at a following ratio, wt %: carbon (C) 0.02-0.09, nitrogen (N) 0.025-0.12, silicon (Si) ≤ 0.25, aluminium (Al) ≤ 0.080, manganese (Mn) 0.55-1.8, chrome (Cr) 11.5-16, copper (Cu) up to 0.48, overall molybdenum (Mo) and half of tungsten (W/2) up to 0.90, nickel (Ni) up to 0.90, vanadium (V) up to 0.090, niobium (Nb) up to 0.090, titanium (Ti) up to 0.025, sulphur (S) up to 0.25, iron and formed during melting admixtures are the rest. Compound of steel satisfies the conditions 0.05≤C+N≤0.17, Si+23Al≥0.20, Si+0.6Al≤0.25, 0.00025≤Al×N≤0.0020, 6.5 ≤ F = (Cr+Mo) + 2(Si+V+Nb) - 27(C+N) -(Ni+Mn/2+Cu/3) ≤13.

EFFECT: increased steel machinability, weldability, corrosion resistance and thermal conductivity.

4 cl, 1 tbl