METHOD OF PRODUCTION OF BIMETALLIC INGOT (VERSIONS) Russian patent published in 2005 - IPC

FIELD: special-purpose electro-metallurgy; production of bimetallic ingots by use of electro-slag technology.

SUBSTANCE: proposed method is adaptable for production of ingots having main layer made from carbon low-alloy or alloy steel and welded-on (cladding) layer made from corrosion-resistant steel; these ingots are subjected to rolling in bimetallic strips and sheets. Alloy steel used for making the main layer has the following composition, mass-%: carbon, 0.05-0.25; silicon, 0.01-0.50; manganese, 0.20-0.60; phosphorus, no more than 0.025; sulfur, no more than 0.020; chromium, 0.7-2.5; molybdenum, 0.2-1.0; iron and unavoidable admixtures, arsenic inclusive being the remainder. Melting the consumable electrodes at content of arsenic in steel lesser than 0.005% is performed at current of 9.0-10.0 kA and at content of arsenic no less than 0.005% melting is performed at current set in accordance with expression I≥9.5+100(As), where I is magnitude of current at each consumable electrode; kA, (As) is content of arsenic in steel, mass-%. Bimetallic ingot is then subjected to slow cooling to ensure rate of cooling on cladding layer surface not exceeding 50°C/h at temperature of 500°C. According to another version, main layer is made from low-alloy steel at the following composition, mass-%: silicon, 0.01-0.80; carbon, 0.05-0.25; manganese, 0.20-1.60; phosphorus, no more than 0.025; sulfur, no more than 0.020; iron and unavoidable admixture, arsenic inclusive being the remainder. Melting the consumable electrodes at content of arsenic in steel of main layer lesser than 0.005% is performed at magnitude of current of 8.0-10.0 kA and at content of arsenic no less than 0.005% melting is performed at magnitude of current determined in the following expression I≥9.0+100 (As), where I is magnitude of current at each consumable electrode, kA, (As) is content of arsenic in steel, mass-%.

EFFECT: enhanced strength and continuity of connection of layers; smooth thick, corrosion resistance and improved quality of cladding layer.

3 cl, 1 tbl, 1 ex