METHOD FOR PRODUCING SHEETS WITH THICKNESS OF 2-20 mm OF HIGH-STRENGTH WEAR-RESISTANT STEEL (OPTIONS) Russian patent published in 2022 - IPC C21D8/02 C22C38/54 B21B1/24 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely to the production of high-strength wear-resistant rolled metal in the form of sheets with a thickness from 2.0 to 20.0 mm, used for mining equipment, excavator buckets, rippers, lining of dump truck bodies. Steel is smelted, containing, wt.%: carbon 0.25-0.40, silicon of no more than 1.40, manganese 0.40-1.00, chromium 0.80-1.40, nickel of no more than 2.0, copper of no more than 0.20, titanium 0.02-0.08, vanadium of no more than 0.03, niobium of no more than 0.10, molybdenum 0.10-0.50, nitrogen of no more than 0.010, aluminum 0.01-0.08, boron 0.001-0.005, sulfur of no more than 0.005, phosphorus of no more than 0.015, iron and unavoidable impurities are the rest, wherein the carbon equivalent Ceq of steel is no more than 0.84. Steel is cast in the form of continuously cast billets with their subsequent heating, rough rolling into a roll of intermediate thickness, finishing rolling of the roll into a sheet of final thickness, winding or heat treatment in the form of quenching and tempering and subsequent cooling in calm air. Rough rolling is carried out to the thickness of the roll, multiple of at least 2.5 thicknesses of the finished sheet. According to one option, finishing rolling is started at a temperature of no more than 980°C and is completed at a temperature of 820-880°C, quenching is carried out at a temperature of 910-950°C, and tempering is carried out at a temperature of 150-260°C, while after finishing rolling, a size of austenitic grain is no more than 40 mcm, and the sheet structure after quenching and tempering consists of martensite. According to the second option, finishing rolling is finished at a temperature of no more than 980°C, and winding is carried out at a temperature of 640-720°C.

EFFECT: obtaining sheets with a thickness of 2-20 mm with a Brinell hardness from 480 to 610 HB and a guaranteed impact strength of at least 30 J.

2 cl, 6 tbl