Efficient alloying method for smelting 38CrMoAl steel

Abstract

The invention discloses an efficient alloying method for smelting 38CrMoAl steel and relates to the field of ferrous metallurgy. The method includes the technological processes of electric arc furnace smelting, LF refining, VD vacuum refining and big round billet continuous casting in sequence. In the electric furnace steel tapping process, aluminum ingots, silicon iron, ferromanganese, ferrochromium, ferromolybdenum, pre-molten refining slag and lime are sequentially added to alloy and slag materials for pre-refining. In the LF refining process, molten steel components except aluminum are adjusted in place. In the VD vacuum refining process, vacuum treatment is conducted twice, 8.5-9.5 kg/t of the aluminum ingots are added at a time after first vacuum treatment is completed, and then second vacuum treatment is conducted to homogenize the molten steel components and denaturalize inclusions. In the big round billet continuous casting process, whole-course protective continuous casting is adopted. The aluminum yield and the molten steel cleanliness can be effectively increased, the service life of a steel ladle can be effectively prolonged, the molten steel is high in controllability of the chemical components and good in castability, and the stability of product performance can be improved.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a high-efficiency alloying method for melting 38CrMoAl steel. Background technique [0002] 38CrMoAl belongs to the advanced nitriding steel in the alloy structural steel. It relies on the dispersion hardening effect of AlN to improve the surface hardness and strength of the steel. It is often used to manufacture parts with special requirements. It has a wide range of uses and a large market demand. The annual demand has exceeded 300,000 tons. [0003] The traditional production process of 38CrMoAl basically adopts the electric furnace-die casting process with relatively low productivity and finished product. The gas content and inclusion content of the steel ingot are high, the spot segregation is serious, and the subsequent processing costs are high. In recent years, with the development of continuous casting steel technology, many iron and steel enterprises have succe...

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Problems solved by technology

[0003] The traditional production process of 38CrMoAl basically adopts the electric furnace-die casting process with lower productivity and finished product. The gas content and inclusion content of the steel ingot are higher, the spot segregation is more serious, and the follow-up processing cost is higher.

[0006] It can be seen that the timing of Al alloying in the existing methods is earlier, the burning loss and oxidation of aluminum are serious in the subsequent smelting process, and the action time of Al and the ladle refractory is longer, which reduces the life of the ladle. Deteriorating the cleanliness of molten steel

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