METHOD FOR MANUFACTURE OF PLATE-ROLLED PRODUCT WITH HIGH DEFORMATION CAPACITY, PLATE-ROLLED PRODUCT Russian patent published in 2018 - IPC C21D8/02 C21D9/46 C22C38/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular for the production of plate-rolled products. To increase the deformation capacity of rolled steel, cold-resistance by creating a ferrite-martensitic/bainitic structure, the method comprises producing a continuous cast steel billet containing, wt%: carbon 0.05÷0.08; manganese 1.5÷2.5; silicon 0.10÷0.50; aluminium 0.01÷0.05; titanium 0.005÷0.03; niobium 0.01÷0.15; vanadium 0.01÷0.10; molybdenum 0.01÷0.5; nickel 0.01÷0.5; copper 0.01÷0.3; chromium 0.01÷0.3; nitrogen 0.002÷0.008; sulphur 0.003 or less; phosphorus 0.003÷0.015; iron – the balance, wherein the total content of molybdenum, nickel, copper, chromium does not exceed 1 %, the coefficient of crack resistance does not exceed 0.24 %, austenitisation of the billet at 1,150÷1,200 °C, cooling the rolled stock with water or air, final deformation by 60÷85 % in the range of 880÷820 °C in a single-phase austenitic region, and the deformation is terminated at a temperature determined by the chemical composition of the steel: T_kp=910-200C-60Mn+25Si-36Ni-20Cr-20Cu±20 °C, followed by multistage cooling of the strip first in air to a temperature T_no=880-75Mn-25Si-65Cr-33Ni-75Mo-270(1-exp(-1.33C)±20 °C by moving along the roller table towards the accelerated cooling installation at a rate that is determined by the formula depending on the final thickness of the rolled product (H, mm) and the temperature difference of the end of rolled product (T_kp) and the beginning of accelerated cooling (T_no): , further accelerated by water at a rate of 20÷50 °C/s to the accelerated cooling completion temperature (T_zo), defined by the formula: T_zo=400-420C-30Mn-15(Si+Cr+Ni+Mo)±20 °C.

EFFECT: increasing the deformation capacity of rolled product and cold resistance.

6 cl, 3 dwg, 4 tbl