Manufacturing method of ultra-purity industrial pure iron

Abstract

The invention discloses a manufacturing method of ultra-purity industrial pure iron and belongs to the technical field of metal smelting. The manufacturing method comprises steps as follows: (1) EBT smelting; (2) LF smelting; (3) vacuum degasing by a VD furnace; (4) casting. According to the manufacturing method, a slag system CaO+CaF2+CaC2 and a lanthanum-cerium alloy are adopted in the LF smelting step for deoxidization and desulfurization, and the content of various impurity elements is controlled within the range required by the technology. The manufactured ultra-purity industrial pure iron is purer, the sulfur content is controlled to be lower than 0.0008wt%, the residual element content is lower than 0.08wt%, and superior secondary hardened steel, high-class blade steel and stainless steel can be produced.

Description

Technical field [0001] The invention relates to the field of metal smelting, in particular to a manufacturing method of ultra-purity industrial pure iron. Background technique [0002] Secondary hardening steel is a carbon-containing Cr-Ni-Co-Mo series of high-purity steel, used to manufacture aircraft landing gear, beams, axles and other parts. The chemical composition requirements of pure iron used in this type of steel (wt% ) Is: C≤0.3, Si≤0.05, Mn≤0.05, S≤0.001, P≤0.003, Al≤0.005, Ti≤0.005; the pure iron has no deoxidizing elements, and silicon and manganese cannot be used in the reduction stage of steelmaking The deoxidizers for aluminum and titanium cannot be manufactured according to the existing technology and conventional smelting process. [0003] At present, GB9971 and GB6983 are used in China to produce pure iron and industrial pure iron as raw materials, which are used to manufacture electromagnetic components, soft magnetic materials, and also used to manufacture mat...

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Problems solved by technology

[0002] Secondary hardening steel is a kind of carbon-containing Cr-Ni-Co-Mo series high-purity steel, which is used to manufacture aircraft landing gear, beams, shafts and other parts. The chemical composition requirements of pure iron used in this type of steel (wt% ) is: C ≤ 0.3, Si ≤ 0.05, Mn ≤ 0.05, S ≤ 0.001, P ≤ 0.003, Al ≤ 0.005, Ti ≤ 0.005; this pure iron has no deoxidizing elements, and it cannot use silicon and manganese in the reduction stage of steelmaking , aluminum, titanium deoxidizer, according to the existing technology and conventional smelting process, it is impossible to manufacture this type of steel

However, there are the following disadvantages: the process method is more complicated, and the sulfur content in the obtained pure iron is relatively high

[0005] At present, Japan uses electrolytic method to manufacture high-purity industrial pure iron, the purity can reach 99.9% iron content, but its price is very high, and the cost for producing secondary hardened steel, maraging steel and high-purity stainless steel is high

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