SA542TypeDCL4a steel plate production process

(1) SA542TypeDCL4a steel plate is a low-phosphorus steel plate. It adopts electric arc furnace + refining furnace + die casting process to make steel and prepare steel ingots. In order to ensure the P content in molten steel, control the P in molten steel after the electric arc furnace taps ≤ 0.004% , P≤0.002% after controlling the refining furnace to remove P, in order to ensure the qualified rate of steel plate flaw detection, the molten steel should keep the vacuuming time ≥20min, and the standing time after vacuuming should be ≥10min.

(2) The SA542TypeDCL4a steel ingot is heated and kept in the soaking furnace, the heating temperature is 1230-1280, and the heat is kept for 3-4 hours. After the billet is opened, the billet is transferred to the slow cooling pit for preheating annealing. The preheating annealing temperature is 630-650, and the heat preservation is 24 hours. -26h; after the annealing, the billet strip is cleaned and installed in a continuous furnace for hot rolling, and the heating and rolling temperature is 1230-1280, and the heat preservation is 2-3h. 75h, destacking temperature 50-100.

(3) The SA542TypeDCL4a steel plate after rolling is accelerated and cooled after normalizing twice. The first normalizing temperature is 940-960, the heat preservation is 200min-250min, the quenching machine is rocked for 40min-50min, cooled to room temperature, and the second normalizing temperature For 930-950, keep warm for 200min-250min, shake in the quenching machine for 40min-50min, and cool to room temperature.

(4) After cooling, the SA542TypeDCL4a steel plate is tempered to obtain a finished steel plate. The tempering temperature is 690-710℃, the furnace time is 460min-490min, and the furnace is air-cooled.