MATERIAL FOR HOT FORMING AND METHOD OF ITS PRODUCTION Russian patent published in 2024 - IPC C22C38/38 C22C38/32 C22C38/28 C22C38/26 C22C38/24 C21D8/02 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to a steel sheet used to produce hot-stamped parts. Steel sheet contains, in wt.%: carbon (C) in amount of 0.28 to 0.50, silicon (Si) in amount of 0.15 to 0.70, manganese (Mn) in amount of 0.5 to 0.70, 2.0, phosphorus (P) in amount of less than or exactly 0.05, sulfur (S) in an amount of less than or exactly 0.01, chromium (Cr) in amount of 0.1 to 0.5, boron (B) in amount of 0.001 to 0.005, an additive containing at least one of titanium (Ti), niobium (Nb) and vanadium (V), in amount of less than or exactly 0.1, rest is iron (Fe) and unavoidable impurities. Sheet contains fine-grained precipitates distributed in steel sheet, wherein fine precipitates contain nitride or carbide of at least one of titanium (Ti), niobium (Nb) and vanadium (V), and trapped hydrogen. Fine-grained precipitates are formed in an amount of more or exactly 25,000 particles and less or exactly 30,000 particles per unit area (100 mcm²), wherein more or exactly 90% of the formed fine-grained precipitates have a diameter of less than or exactly 0.01 mcm. Tensile strength of steel sheet after hot forming is more than or exactly 1,680 MPa, bendability of steel sheet after hot forming is more than or exactly 40°, and the amount of activated hydrogen in the steel sheet after hot forming is less than or exactly 0.5 wt.ppm.

EFFECT: hot-forged parts produced from steel sheet have high mechanical characteristics and characteristics of delayed hydrogen cracking.

8 cl, 5 dwg, 3 tbl