Alloying steel-making technology by directly reducing molybdenum oxide in converter

Abstract

The invention discloses an alloying steel-making technology by directly reducing molybdenum oxide in a converter. The alloying steel-making technology comprises the following steps that (1), molybdenum oxide powder, volatilizing inhibition agent powder, steel scraps and molten iron are prepared according to smelting requirements of 42CrMo steel; (2), the molybdenum oxide and a volatilizing inhibition agent are compressed and prepared into molybdenum raw material particles with the volume being 1-10 cm3; (3) the steel scraps and a part of the molybdenum raw material particles are added into themolten iron in the converter; and (4) smelting is conducted according to the smelting technology of the 42CrMo steel, the rest of the molybdenum raw material particles are added after blowing is conducted for 5 minutes. According to the alloying steel-making technology, a reducing agent does not need to be added additionally, molybdenum in the molybdenum sesquioxide can be reduced to a molybdenumsingle substance to enter the molten iron by utilizing iron and carbon in the molten iron, the molybdenum sesquioxide can be effectively prevented from sublimating and flowing out along with slag, the molybdenum yield is improved effectively, and the viscosity of molten steel cannot be increased to block a water port. In addition, compared with utilizing ferromolybdenum, the hardenability and thetensile strength are improved to some extent.

Description

technical field [0001] The invention relates to the field of converter steelmaking. More specifically, it relates to the direct reduction alloying process of molybdenum oxide in a converter. Background technique [0002] Molybdenum is an alloying element commonly used in alloy steel. When the content of molybdenum is low, molybdenum is soluble in ferrite and strengthens ferrite. Molybdenum has a strong affinity with carbon, and it is easy to form carbides and alloy infiltration in steel. Carbon body, promotes the formation of pearlite, refines the pearlite structure, and can significantly improve the hardenability of steel. Because molybdenum increases the softening and strengthening recovery temperature after deformation strengthening, and strongly improves the creep resistance of ferrite, effectively suppresses the aggregation of cementite at 450-600°C, and promotes the precipitation of special carbides. The most effective alloying element for thermal strength. And with...

AI Technical Summary

Problems solved by technology

[0005] 1. Add carbon into molten steel as a reducing agent. Carbon and molybdenum oxide react to produce a large amount of carbon monoxide to form bubbles. When a large amount of molybdenum oxide is added, it is easy to cause a large boiling phenomenon; and carbon reduction of molybdenum oxide is a strong endothermic reaction, making Increased power consumption

[0006] 2. When silicon is used as a reducing agent, the silicon dioxide produced by the reaction enters the slag, and the addition of calcium oxide will increase the amount of slag, and the slag will carry a part of molybdenum oxide and cause the loss of molybdenum oxide

[0007] 3. The increase of aluminum oxide content in molten steel increases the viscosity of molten steel, which can lead to the deposition of aluminum oxide on the inner wall of the submerged nozzle, causing the nozzle to be blocked and continuous casting impossible; aluminum can also be combined with silicon dioxide and carbon monoxide in the nozzle Interaction, resulting in the formation of aluminum oxide at the interface between the molten steel and the nozzle to block the nozzle

[0008] 4. Quicklime is very easy to hydrate in the air, so it is subject to certain restrictions when used to inhibit the volatilization of molybdenum trioxide

[0009] 5. Most of them are suitable for electric furnace steelmaking, but few are suitable for converter steelmaking, and the yield of molybdenum at the end of blowing when used in converter steelmaking is often below 92%.