Method for producing 23MnB steel by adopting vacuum process

Abstract

The invention discloses a method for producing 23MnB steel by adopting a vacuum process, and belongs to the field of ferrous metallurgy. For solving the technical problem, the invention provides the method, which ensures that a small-size continuous casting machine realizes smooth casting, for manufacturing the 23MnB steel. The method comprises the following steps of: a, smelting in a converter; b, adding calcium carbide during tapping, so that the oxygen activity of the molten steel is below 0.0025 percent; c, refining in a low frequency (LF) furnace, wherein 3.5 to 4.5 kg of calcium carbideis added into each ton of molten steel before refining and heating, and 0.15 to 0.45 kg of metallic aluminum is added into each ton of molten steel during heating; d, performing vacuum circulating treatment, adding aluminum during treating to keep aluminum content between 0.011 and 0.016 percent, adding ferrotitanium to keep the titanium content between 0.02 and 0.06 percent, and adding ferroboron to keep the boron content between 0.0005 and 0.003 percent; and e, performing continuous casting. The method can be applied to a large-size continuous casting machine, and can ensure that the small-size continuous casting machine realizes smooth casting.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a method for producing 23MnB steel by a vacuum method. Background technique [0002] A small amount of boron (about 0.001%) can be adsorbed on the austenite grain boundary, reduce the grain boundary energy, inhibit the formation of ferrite nuclei, and double the hardenability of medium and low carbon steels. Therefore, medium and low carbon steels often Add 0.0005-0.003% trace amount of boron to improve hardenability of steel. However, boron is one of the most active elements, which can form stable inclusions with residual oxygen and nitrogen in steel, and lose its beneficial effect. Only boron in solid solution can play a beneficial role. [0003] Existing studies have shown that boron has a strong affinity with oxygen and nitrogen, and boron is easily oxidized to generate B 6 O or B 2 o 3 , or combined with nitrogen to form BN, these are harmful substanc...

AI Technical Summary

Problems solved by technology

Specifically, molten steel with more than 0.02% aluminum or acid-soluble aluminum will produce a certain amount of Al in the casting process 2 o 3 , these Al 2 o 3 It will make the mold nozzle of the continuous casting machine smaller, which will affect the continuous casting, and even block the mold nozzle of the continuous casting machine, especially on the continuous casting machine with a cross-section of 200×200mm or below 200×200mm, making the small-sized continuous casting machine unable to cast