阅读说明：本技术 一种FeCrAl合金钢带的制备方法 (Preparation method of FeCrAl alloy steel strip ) 是由 吴晓东 王启丞 王忠英 于 2021-08-03 设计创作，主要内容包括：本发明属于冶金技术领域,公开了一种FeCrAl合金钢带的制备方法。制备方法是：按FeCrAl合金的化学组分,以工业纯铁、纯铝、纯铬、纯稀土金属为原料配料,采用真空感应炉熔炼,在1600～1650℃条件下浇铸成钢锭,将FeCrAl合金钢锭装入加热炉,在1100～1200℃加热120～150min,将铸坯在1000～1100℃条件下锻造成厚度为20～30mm的板坯,然后将板坯在840～940℃条件下热轧成厚度为2.0～3.0mm的钢带,并将钢带快冷至200～400℃。本发明具有成本低、工艺简单的特点,所制备的FeCrAl合金钢带的脆性改善明显,塑性提高显著,提高了成材率,产品性能稳定性大幅提高。(The invention belongs to the technical field of metallurgy and discloses a preparation method of a FeCrAl alloy steel strip. The preparation method comprises the following steps: according to the chemical components of the FeCrAl alloy, industrial pure iron, pure aluminum, pure chromium and pure rare earth metal are used as raw materials, a vacuum induction furnace is adopted for smelting, steel ingots are cast at 1600-1650 ℃, the FeCrAl alloy steel ingots are loaded into a heating furnace and heated at 1100-1200 ℃ for 120-150 min, the casting blanks are forged into slabs with the thickness of 20-30 mm at 1000-1100 ℃, then the slabs are hot-rolled into steel strips with the thickness of 2.0-3.0 mm at 840-940 ℃, and the steel strips are rapidly cooled to 200-400 ℃. The method has the characteristics of low cost and simple process, the brittleness of the prepared FeCrAl alloy steel strip is obviously improved, the plasticity is obviously improved, the yield is improved, and the product performance stability is greatly improved.)

1. A preparation method of a FeCrAl alloy steel strip comprises the following components in percentage by mass: less than or equal to 0.002 wt% of C, less than or equal to 0.003 wt% of N, less than or equal to 0.003 wt% of S, less than or equal to 0.02 wt% of P, Cr: 18-25 wt%, Al: 4.0-5.6 wt%, RE: 0.1 to 0.25 wt%, the balance being Fe and unavoidable impurities; the method is characterized by comprising the following steps:

(1) smelting: smelting FeCrAl alloy in a vacuum induction smelting furnace by taking industrial pure iron, pure aluminum, pure chromium and pure rare earth metals as raw materials, and casting into FeCrAl alloy ingots;

(2) heating: putting the FeCrAl alloy steel ingot obtained in the step (1) into a heating furnace, and heating for 120-150 minutes at 1100-1200 ℃;

(3) hot rolling: carrying out rough rolling and finish rolling on the FeCrAl alloy steel ingot obtained in the step (2) to obtain a steel strip with the thickness of 2.0-3.0 mm;

(4) and (3) cooling: and (4) rapidly cooling the steel strip obtained in the step (3) to 200-400 ℃.

2. The method according to claim 1, wherein in the step (1), the purity of pure aluminum is 99.5%, the purity of pure chromium is 99.5%, and the purity of pure rare earth metal is 99.5%.

3. The method according to claim 1, wherein in the step (1), the FeCrAl alloy is melted in the order of Fe, Cr, Al, and rare earth under vacuum, and cast into an FeCrAl alloy ingot after the melting.

4. The manufacturing method according to claim 1, wherein in the step (3), the rough rolling temperature is 1000 to 1100 ℃, the rough rolling is set to 5 or 7 passes, and the final outlet thickness of the rough rolling is 20 to 30 mm; and (5) after the rough rolling is finished, using a coil box to preserve heat of the FeCrAl alloy steel strip.

5. The manufacturing method according to claim 1, wherein in the step (3), the finish rolling is performed for 7 passes, the first pass deformation amount is 30-40%, and the finish rolling temperature is controlled to be 840-940 ℃.

6. The manufacturing method according to claim 1, wherein in the step (3), the steel slab of FeCrAl alloy is hot-rolled using a hot continuous rolling mill.

7. The manufacturing method according to claim 1, wherein in the step (4), the steel strip is rapidly cooled to 200-400 ℃ by: and spraying water to the FeCrAl alloy steel strip so as to cool the surface of the FeCrAl alloy steel strip to a target temperature within the time range of 15-30 s.

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to a preparation method of a FeCrAl alloy steel strip.

Background

The FeCrAl high-temperature alloy is an electrothermal alloy material with a low-carbon nitrogen ferrite structure, can work at the high temperature of 1000-1400 ℃, and is widely applied to the fields of metallurgy, chemical industry, food, household appliances, electric heating elements, internal combustion engine exhaust purifier carriers and the like. At present, the FeCrAl high-temperature alloy industry gradually advances towards the high-end market, the requirements on high, fine and thin products of FeCrAl high-temperature alloy products are stricter, and the requirements on the product characteristics such as dimensional tolerance, plate shape, surface and the like of the products are more strict.

The specific gravity segregation is easy to generate in the FeCrAl alloy due to the addition of aluminum, the lattice distortion of alloy solid solution is increased, the strong embrittlement of ferrite is caused by the defects of easy occurrence of brittle fracture and the like in the processing process, and the toughness of the alloy is rapidly reduced. The difficulty of the FeCrAl alloy hot rolling process is as follows: when the temperature is lower, the cold brittleness of the FeCrAl alloy is increased sharply, and cracks even transverse cracks are generated in the FeCrAl alloy; as high-aluminum ferrite structure steel, the steel has the tendency of rapid growth of crystal grains under high heating temperature, and the thermoplasticity of the blank is influenced; after hot rolling, rapid cooling is needed, particularly a temperature range around 475 ℃ is avoided, otherwise, precipitates are generated, the hot-rolled coil performance is deteriorated, and strip breakage is easy to occur in subsequent production. If the hot rolling process parameters are not properly controlled, the ductile-brittle transition temperature of the iron-chromium-aluminum alloy hot rolled steel coil is up to more than 50 ℃, and stable production at room temperature cannot be realized.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and aims to provide the preparation method of the FeCrAl alloy steel strip with low cost and simple process.

In order to achieve the purpose, the invention adopts the technical scheme that:

the FeCrAl alloy comprises the following components in percentage by mass: c is less than or equal to 0.002, N is less than or equal to 0.003, S is less than or equal to 0.003, P is less than or equal to 0.02, Cr: 18-25, Al: 4.0-5.6, RE: 0.1 to 0.25, and the balance of Fe and inevitable impurities.

The preparation method of the FeCrAl alloy steel strip comprises the following steps:

(1) smelting: smelting FeCrAl alloy in a vacuum induction smelting furnace by taking industrial pure iron, pure aluminum, pure chromium and pure rare earth metals as raw materials, and casting into FeCrAl alloy ingots;

(2) heating: putting the FeCrAl alloy steel ingot obtained in the step (1) into a heating furnace, and heating for 120-150 minutes at 1100-1200 ℃; obtaining alloy steel ingots of 0Cr21Al6, 0Cr23Al5 or 0Cr25Al 5;

(3) hot rolling: carrying out rough rolling and finish rolling on the FeCrAl alloy steel ingot obtained in the step (2) to obtain a steel strip with the thickness of 2.0-3.0 mm;

(4) and (3) cooling: and (4) rapidly cooling the steel strip obtained in the step (3) to 200-400 ℃.

In the technical scheme, in the step (1), the purity of pure aluminum is 99.5%, the purity of pure chromium is 99.5%, the purity of pure rare earth metal is 99.5%, smelting is carried out in a vacuum induction smelting furnace according to the sequence of Fe, Cr, Al and rare earth, the content of impurity elements such as C, S, P, N, O in the alloy is strictly controlled, and casting is carried out to obtain a FeCrAl alloy ingot after smelting;

and (3) carrying out hot rolling on the FeCrAl alloy steel ingot by adopting a hot continuous rolling mill. The rough rolling temperature is 1000-1100 ℃, the rough rolling is set to be 5 or 7, the outlet thickness of the rough rolling is 20-30 mm, and a hot coil box is used for preserving the heat of the FeCrAl alloy steel strip after the rough rolling is finished; carrying out finish rolling for 7 passes, wherein the first pass deformation is 30-40%, and the final rolling temperature is controlled to be 840-940 ℃;

in the step (4), the specific manner of rapidly cooling the steel strip to 200-400 ℃ is as follows: and spraying water to the FeCrAl alloy steel strip so as to cool the surface of the FeCrAl alloy steel strip to a target temperature within the time range of 15-30 s.

The invention has the beneficial effects that:

the preparation method improves the low-temperature ductility of the FeCrAl alloy steel strip, so that the FeCrAl alloy steel strip can be prepared by a traditional rolling mode, and the preparation method has wide applicability, simple process and low cost. Meanwhile, the invention adopts a vacuum induction furnace for smelting, can effectively reduce the impurity content in the steel and improve the alloy plasticity. The alloy can be smoothly rolled into a plate blank with the thickness of 20-30 mm in the rough rolling process, the shape of a raw material suitable for hot rolling can be provided, crystal grains and impurities can be crushed, the plasticity of the material is improved, a thinner plate can be provided in the hot rolling process, the crystal grains can be effectively refined, and the plasticity of the plate is obviously improved.

Detailed Description

The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.

The test methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.

Example 1

A vacuum induction furnace is adopted to cast a 0Cr21Al6 alloy steel ingot, and the chemical components of the alloy steel ingot comprise the following components in percentage by weight: less than or equal to 0.002% of C, less than or equal to 0.003% of N, less than or equal to 0.003% of S, less than or equal to 0.02% of P, Cr: 20-21, Al: 5.5-6.0, RE: 0.1 to 0.15, and the balance of Fe and inevitable impurities.

The preparation method of the FeCrAl alloy steel strip comprises the following steps:

(1) smelting: smelting FeCrAl alloy in a vacuum induction smelting furnace by taking industrial pure iron, pure aluminum, pure chromium and pure rare earth metals as raw materials, and casting the alloy into an alloy ingot;

(2) heating: placing the FeCrAl alloy steel ingot into a heating furnace, and heating for 120-150 minutes at 1100-1200 ℃; the heating temperature and time are related to the size of the alloy steel ingot;

(3) rough rolling: and carrying out rough rolling on the steel ingot at the temperature of 1000-1100 ℃, wherein the outlet thickness of the steel ingot after the rough rolling is 20-30 mm.

(4) Hot rolling: carrying out finish rolling on the FeCrAl alloy steel ingot, wherein the first-pass deformation is 30-40%, and the finish rolling temperature is controlled to be 840-940 ℃, so as to obtain a steel strip with the thickness of 2.5 mm;

(5) and (3) cooling: and rapidly cooling the 2.5mm steel strip to 200-400 ℃.

Example 2

A vacuum induction furnace is adopted to cast a 0Cr23Al5 alloy steel ingot, and the chemical components of the alloy steel ingot comprise the following components in percentage by weight: less than or equal to 0.002% of C, less than or equal to 0.003% of N, less than or equal to 0.003% of S, less than or equal to 0.02% of P, Cr: 22-24, Al: 4.5-5.0, RE: 0.1 to 0.15, and the balance of Fe and inevitable impurities.

The preparation method of the FeCrAl alloy steel strip comprises the following steps:

(1) smelting: smelting FeCrAl alloy in a vacuum induction smelting furnace by taking industrial pure iron, pure aluminum, pure chromium and pure rare earth metals as raw materials, and casting the alloy into an alloy ingot;

(2) heating: placing the FeCrAl alloy steel ingot into a heating furnace, and heating for 120-150 minutes at 1100-1200 ℃;

(3) rough rolling: and carrying out rough rolling on the steel ingot at the temperature of 1000-1100 ℃, wherein the outlet thickness of the steel ingot after the rough rolling is 20-30 mm.

(4) Hot rolling: carrying out finish rolling on the FeCrAl alloy steel ingot, wherein the first-pass deformation is 30-40%, and the finish rolling temperature is controlled to be 840-940 ℃, so as to obtain a steel strip with the thickness of 2.8 mm;

(5) and (3) cooling: and rapidly cooling the 2.8mm steel strip to 200-400 ℃.

Example 3

A vacuum induction furnace is adopted to cast a 0Cr25Al5 alloy steel ingot, and the chemical components of the alloy steel ingot comprise the following components in percentage by weight: less than or equal to 0.002% of C, less than or equal to 0.003% of N, less than or equal to 0.003% of S, less than or equal to 0.02% of P, Cr: 24-26%, Al: 4.5-5.0%, RE: 0.1 to 0.2%, and the balance of Fe and inevitable impurities.

The preparation method of the FeCrAl alloy steel strip comprises the following steps:

(1) smelting: smelting FeCrAl alloy in a vacuum induction smelting furnace by taking industrial pure iron, pure aluminum, pure chromium and pure rare earth metals as raw materials, and casting the alloy into an alloy ingot;

(2) heating: placing the FeCrAl alloy steel ingot into a heating furnace, and heating for 120-150 minutes at 1100-1200 ℃;

(3) rough rolling: and carrying out rough rolling on the steel ingot at the temperature of 1000-1100 ℃, wherein the outlet thickness of the steel ingot after the rough rolling is 20-30 mm.

(4) Hot rolling: carrying out finish rolling on the FeCrAl alloy steel ingot, wherein the first-pass deformation is 30-40%, and the finish rolling temperature is controlled to be 840-940 ℃, so as to obtain a steel strip with the thickness of 3.0 mm;

(5) and (3) cooling: and rapidly cooling the 3.0mm steel strip to 200-400 ℃.