HIGH IMPACT STEEL SHEET WITH HIGH STABILITY TO DELAYED FAILURE AND LOW-TEMPERATURE SHOCK VISCOSITY, AND HIGH IMPACT PART, MANUFACTURED WITH ITS USE Russian patent published in 2017 - IPC C22C38/38 C22C38/32 C21D9/46 C21D1/18 

FIELD: metallurgy.

SUBSTANCE: sheet is made of steel, containing wt %: C from 0.20 to 0.42, Si from 0.06 to 0.5, Mn from 0.2 to 2.2, Cr from 0.1 to 2.5, B from 0.0005 to 0.01, O from 0.0020 to 0.020, Al from 0.001 to 0.03, Ti from 0.001 to 0.05, N 0.1 or less, P 0.03 or less, S 0.02 or less, the rest is Fe and unavoidable impurities. In steel there are from 5×10³ particles per mm² up to 1×10⁵ particles per mm² of manganese oxides (Mn), having the maximum length from 1 mcm up to 5 mcm and there are from 1.7×10² particles per mm² upto 5×10³ particles per mm² of complex Mn-Si oxides, having the short axis length 1 mcm or more and the length in the longitudinal direction of 10 mcm or less.

EFFECT: steel has the high stability to delayed fracture and low-temperature shock viscosity.

7 cl, 5 dwg, 16 tbl, 8 ex