Method for revolving furnace smelting 45CrMnMo steel

Abstract

The invention relates to a producing method for revolving furnace smelting 45CrMnMo steel, which belongs to metallurgy field. The technical scheme includes the following steps: a) adding desulphurizing hot-metal into the revolving furnace, and smelting with adding lime stock, b) gradually adding the chromium irons, ferro-molybdenum and silicon-manganese alloy confected by proportion into molten steel parcel during the revolving furnace exporting molten steel, and adding coherer aluminum into the molten steel parcel to be deoxidized at the same time, c) blowing argon gas into the molten steel in the ladle after tapping, d) vacuum treating the molten steel and carrying through micro-adjustment with the chemical constituents in the vacuum procedure at the same time, then casting 45CrMnMo steel. The invention provides a method for revolving furnace producing 45CrMnMo steel, in which the recovery rate of chromium iron is higher, saves more time, improves economic benefit, and provides a better choice for producing 45CrMnMo steel.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a method for smelting 45CrMnMo steel in a converter. Background technique [0002] 45CrMnMo steel is a special steel used in the production of oil drill collars. The drill collar is a key component of the drill string in oil drilling facilities, and it is the part that connects the drill bit and the drill pipe. The main function is to transmit torque to the drill bit, provide drilling pressure, ensure the rigidity and stability of the lower part of the drill string and prevent well deviation. The chemical composition (weight%) of 45CrMnMo steel is: carbon 0.42-0.48%; silicon 0.15-0.30%; manganese 0.75-1.20%; molybdenum 0.15-0.25%; chromium 0.75-1.20%; . Each item of low-magnification structure is ≤2.0, each level of non-metallic inclusions is ≤2.5, and the total level of non-metallic inclusions is ≤16. The grain size of 45CrMnMo steel after heat treatment is ≥5.0, the yi...

AI Technical Summary

Problems solved by technology

In addition, when using electric furnace and converter to smelt ordinary alloy steel containing chromium and molybdenum, chromium and ferromolybdenum alloy are added to the converter molten steel, and 10% of the chromium forms chromium oxides and enters the slag, which thickens the slag and makes the alloy The yield is low, and there is no way to solve it, resulting in the yield of ferrochromium alloy being lower than 90%, and the yield rate of ferromolybdenum alloy being only about 95%.

At the same time, the existing technology also has the defect that the smelting time will be extended correspondingly due to the addition of chromium and ferromolybdenum alloys.

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