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A kind of heat-resistant steel and preparation method thereof

A heat-resistant steel and molten steel technology, applied in the field of alloy steel, can solve the problems of small modification effect, inclusions, burning loss, etc.

Active Publication Date: 2015-08-19
SHANGHAI SUPEZET ENG TECH CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the production or preparation process of rare earth heat-resistant steel, the addition amount of rare earth elements is different, and its absorption effect is different during the solidification process of molten steel, so the modification effect on steel is quite different: if the addition amount is too small, the modification effect is small; If the amount added is too much, it is easy to have defects such as inclusions in the steel structure, which will obviously damage the mechanical properties and high temperature corrosion resistance of the heat-resistant steel.
[0006] Moreover, when the cast alloy is smelted, whether it is an inoculant or a modifier, when it is added to the alloy liquid, its particle size should be kept at a certain size, generally at least millimeter level, if the size is too small, for rare earth elements, it will be melted, If the size is too large, it is not conducive to the role of rare earth elements. Therefore, the utilization rate of rare earth elements in heat-resistant steel needs to be improved.

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  • A kind of heat-resistant steel and preparation method thereof
  • A kind of heat-resistant steel and preparation method thereof
  • A kind of heat-resistant steel and preparation method thereof

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preparation example Construction

[0037] The present invention also provides a method for preparing the above heat-resistant steel, including the following steps:

[0038] Combine the first mass part of Fe with 0.3~1.0wt% of C, 1.0~2.5wt% of Si, 0.3~2.5wt% of Mn, 15~25wt% of Cr, 5~15wt% of Ni, 0.1~2.0wt % Mo, 0~0.03wt% S, and 0~0.03wt% P are mixed and melted to obtain molten steel;

[0039] Cover the surface of 0.05-0.5 parts by weight with the second part by mass of Fe, pour the molten steel into it, and let it stand to obtain heat-resistant steel;

[0040] The particle size of the rare earth is nanometer and / or micrometer.

[0041] Wherein, the raw materials are the same as those described above, and will not be repeated here.

[0042] According to the present invention, the specific steps of the mixing and smelting are: mixing the first part by mass of Fe with 0.3-1.0wt% of C, 0-0.03wt% of S, and 0-0.03wt% of P, and heating until melting, Preferably heat to 1200℃~1400℃, then add 1.0~2.5wt% Si and 0.3~2.5wt% Mn, con...

Embodiment 1

[0056] 1.1 According to the composition of raw materials: 0.3wt% C, 1.0wt% Si, 2.5wt% Mn, 15wt% Cr, 5.0wt% Ni, 2.0wt% Mo, 0.05wt% Y, S≤0.03 wt%, P≤0.03wt% and the balance of Fe. Weigh out mineral raw material scrap steel, ferromanganese, ferrosilicon, ferrochrome, pure nickel, ferromolybdenum and rare earth Y, with a total weight of 200kg.

[0057] 1.2 The 0.1kg rare earth Y weighed in 1.1 was manually crushed to about 2~3mm, and then added to the ball milling tank, and after adding 0.5% of the rare earth Y weight in ethanol solution, stainless steel grinding balls (two sizes of mills) Ball size: 10mm and 5mm; the weight ratio of the two grinding balls is 1:1), the ball-to-battery ratio is 10:1, sealed and vacuumed to 10 -1 Pa, filled with argon gas and ball milled for 20 hours to obtain rare earth Y powder with an average particle size of 300 μm, which was sealed and stored.

[0058] 1.3 Heat the steel scrap weighed in 1.1 in a 200kg medium frequency induction electric furnace to...

Embodiment 2

[0066] 2.1 According to the composition of raw materials: 1.0wt% C, 2.5wt% Si, 0.3wt% Mn, 25wt% Cr, 15wt% Ni, 0.1wt% Mo, 0.15wt% Y, S≤0.03wt %, P≤0.03wt% and the balance of Fe. Weigh out mineral raw material scrap steel, ferromanganese, ferrosilicon, ferrochrome, pure nickel, ferromolybdenum and rare earth Y, with a total weight of 200kg.

[0067] 2.2 Manually crush the 0.3kg rare earth Y weighed in 2.1 to about 2~3mm, then add it to the ball milling tank, and add 0.5% ethanol solution of rare earth Y weight, and then add stainless steel grinding balls (mills of two sizes) Ball size: 10mm and 5mm; the weight ratio of the two grinding balls is 1:1), the ball-to-battery ratio is 10:1, sealed and vacuumed to 10 -1 Pa, filled with argon gas and ball milled for 80 hours to obtain rare earth Y powder with an average particle size of 150 nm, which was sealed and stored.

[0068] 2.3 Heat the steel scrap weighed in 2.1 in a 200kg medium-frequency induction electric furnace to 1400℃ and me...

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Abstract

The invention provides heat-resisting steel and a preparation method thereof. The method comprises the steps of mixing a first part by mass of Fe with C, Si, Mn, Cr, Ni, Mo, S and P, and smelting so as to obtain liquid steel; and covering a second part by mass of Fe on the surface of rare earth, pouring the liquid steel, and standing, thereby obtaining the heat-resisting steel, wherein the particle diameter of the rare earth is nano-scale and / or micron-scale. Compared with the prior art, the method has the advantages that the rare earth with the nano-scale or micron-scale particle diameter is adopted to modify the heat-resisting steel, the surface activation energy of the nano-scale and / or micron-scale rare earth is higher, the surface of the rare earth is covered by iron powder, and then, the liquid steel is added, so that the rare earth can be isolated from the air, the time of contact between the rare earth and the liquid steel is shortened, the oxidation burning loss is reduced, then, the modification effect of a rare-earth element on the heat-resisting steel is improved, basic crystal grains of the microstructure of the heat-resisting steel are refined and have the effect of refined crystal grains, meanwhile, the high-temperature elongation percentage of the heat-resisting steel can be increased, and the oxidation resistance of the heat-resisting steel is improved.

Description

Technical field [0001] The invention belongs to the technical field of alloy steel, and particularly relates to a heat-resistant steel and a preparation method thereof. Background technique [0002] Heat-resistant steel refers to steel that has oxidation resistance, sufficient high-temperature strength, and good heat resistance under high-temperature conditions. Heat-resistant steel includes two types: oxidation-resistant steel and heat-strength steel: oxidation-resistant steel is also referred to as non-skinned steel, which generally requires better chemical stability, but bears a lower load; heat-strength steel refers to good performance at high temperatures. Steel with high oxidation resistance and high high temperature strength, which has high strength and good chemical stability at high temperatures. Heat-resistant steel is often used to manufacture parts and components that work at high temperatures in industrial sectors such as boilers, steam turbines, power machinery, in...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/44C22C38/58C22C33/04
Inventor 张锦红皇志富高义民展益彬马利峰邢建东
Owner SHANGHAI SUPEZET ENG TECH CO LTD