阅读说明：本技术 一种含稀土耐候钢及其制备方法 (Rare earth-containing weathering steel and preparation method thereof ) 是由 刘日平 唐轶浩 陈博涵 姬朋飞 李波 景勤 马明臻 张新宇 于 2021-09-07 设计创作，主要内容包括：本发明属于合金技术领域,特别涉及一种含稀土耐候钢及其制备方法。本发明提供的含稀土耐候钢,以质量百分含量计,包括以下元素：Al4～11％、Si0.25～1.8％、P0.01～0.35％、Cu0.1～0.55％、Re0.025～0.55％和余量的Fe。在本发明中,Al有利于降低耐候钢的密度,同时细化晶粒,提高耐候钢的力学性能和耐大气腐蚀性能；Re有利于晶化耐候钢基体,改善耐候钢的力学性能和耐候性能。实施例表明,本发明提供的含稀土耐候钢具有良好的强度、塑性和优异的耐候性。(The invention belongs to the technical field of alloys, and particularly relates to rare earth-containing weathering steel and a preparation method thereof. The rare earth-containing weathering steel provided by the invention comprises the following elements in percentage by mass: 4-11% of Al, 0.25-1.8% of Si, 0.01-0.35% of P, 0.1-0.55% of Cu0.025-0.55% of Re and the balance of Fe. In the invention, Al is beneficial to reducing the density of the weathering steel, refining crystal grains and improving the mechanical property and atmospheric corrosion resistance of the weathering steel; re is beneficial to crystallizing the weathering steel matrix and improving the mechanical property and the weathering property of the weathering steel. The embodiment shows that the rare earth-containing weathering steel provided by the invention has good strength, plasticity and excellent weather resistance.)

1. The rare earth-containing weathering steel is characterized by comprising the following elements in percentage by mass:

4 to 11% of Al, 0.25 to 1.8% of Si, 0.01 to 0.35% of P, 0.1 to 0.55% of Cu, 0.025 to 0.55% of Re, and the balance of Fe.

2. The rare earth-containing weathering steel according to claim 1, further comprising one or more of the following elements in mass percent:

mn, C, Ti, Nb and V.

3. The rare earth-containing weathering steel of claim 1 characterized in that the structure of the rare earth-containing weathering steel includes ferrite and/or austenite.

4. The high aluminum weathering steel according to claim 1 or 3 wherein the structure of the rare earth-containing weathering steel has a width of 20 to 800 μm.

5. The method for preparing the rare earth-containing weathering steel of any of claims 1 to 4, characterized by comprising the steps of:

smelting a raw material containing rare earth weathering steel and then cooling to obtain an ingot;

and carrying out homogenization treatment and rolling deformation treatment on the cast ingot in sequence to obtain the rare earth-containing weathering steel.

6. The preparation method according to claim 5, wherein the temperature of the smelting is 2100-2600 ℃.

7. The preparation method according to claim 5, wherein the homogenization treatment is carried out at a temperature of 925 to 1100 ℃ and for a holding time of 15 to 60 min.

8. The preparation method according to claim 5, wherein the rolling deformation treatment is carried out at a rolling start temperature of 925 to 1100 ℃; the total deformation amount of the rolling deformation treatment is 60-75%.

9. The method according to claim 8, wherein the hot rolling is performed for 5 to 6 passes, and the amount of deformation per pass is independently 10 to 15%.

10. The production method according to claim 9, wherein heat holding is performed between two passes in the hot rolling; the temperature of the heat preservation is 925-1100 ℃ independently, and the time is 4-6 min independently.

Technical Field

The invention belongs to the technical field of alloys, and particularly relates to rare earth-containing weathering steel and a preparation method thereof.

Background

The weathering steel, i.e. the atmospheric corrosion resistant steel, is an alloy steel series between ordinary carbon steel and stainless steel, and is made of ordinary carbon steel with a small amount of copper, chromium and other elements added. Compared with common carbon steel, the weathering steel has better corrosion resistance in the atmosphere; compared with stainless steel, the weathering steel only contains a small amount of alloy elements and is low in price. The weathering steel with low cost and excellent corrosion resistance is widely applied to steel structures such as bridges, vehicles, containers and the like which are exposed to the atmosphere for a long time.

With the development of industry, a large amount of greenhouse gas is discharged into the atmosphere, which makes the atmosphere facing the weathering steel more severely corroded. The weather resistance and mechanical property of the traditional weathering steel (such as Q355NH) can not meet the increasingly strict service requirement, and the addition of rare earth elements into the weathering steel can effectively enhance the weather resistance and improve the mechanical property of the weathering steel. For example, 06CuPTiRE steel and 06CuPRE steel have corrosion resistance superior to carbon steel, and are respectively exposed to the sun in Wuhan, Chengdu and Qingdao areas, and the corrosion resistance is 1.2-2 times that of A2 steel; however, in severe atmosphere, such as industrial marine atmosphere, the steel substrate has insufficient protection, poor strength and poor weather resistance.

Disclosure of Invention

In view of the above, the present invention aims to provide a weathering steel containing rare earth and a preparation method thereof, and the weathering steel containing rare earth provided by the invention has the characteristics of high strength and excellent weathering performance.

In order to achieve the purpose of the invention, the invention provides the following technical scheme:

the invention provides rare earth-containing weathering steel which comprises the following elements in percentage by mass:

4 to 11% of Al, 0.25 to 1.8% of Si, 0.01 to 0.35% of P, 0.1 to 0.55% of Cu, 0.025 to 0.55% of Re, and the balance of Fe.

Preferably, the paint also comprises one or more of the following elements in percentage by mass:

mn, C, Ti, Nb and V.

Preferably, the structure of the rare earth-containing weathering steel includes ferrite and/or austenite.

Preferably, the width of the structure of the rare earth-containing weathering steel is 20-800 μm.

The invention also provides a preparation method of the rare earth-containing weathering steel in the technical scheme, which comprises the following steps:

smelting a raw material containing rare earth weathering steel and then cooling to obtain an ingot;

and carrying out homogenization treatment and rolling deformation treatment on the cast ingot in sequence to obtain the rare earth-containing weathering steel.

Preferably, the smelting temperature is 2100-2600 ℃.

Preferably, the temperature of the homogenization treatment is 925-1100 ℃, and the heat preservation time is 15-60 min.

Preferably, the initial rolling temperature of the rolling deformation treatment is 925-1100 ℃; the total deformation amount of the rolling deformation treatment is 60-75%.

Preferably, the hot rolling times are 5-6 times, and the deformation of each pass is 10-15% independently.

Preferably, heat preservation is carried out between two times in the hot rolling; the temperature of the heat preservation is 925-1100 ℃ independently, and the time is 4-6 min independently.

The invention provides rare earth-containing weathering steel which comprises the following elements in percentage by mass: 4 to 11% of Al, 0.25 to 1.8% of Si, 0.01 to 0.35% of P, 0.1 to 0.55% of Cu, 0.025 to 0.55% of Re, and the balance of Fe. In the invention, Al reduces the density of the weathering steel, simultaneously refines crystal grains, and improves the mechanical property and the (ocean) atmospheric corrosion resistance of the weathering steel; si is beneficial to reducing the density of the weathering steel, reducing the anisotropy tendency of crystals and improving the strength and hardness of the weathering steel; p improves the strength and hardness of the weathering steel and is beneficial to improving the (ocean) atmospheric corrosion resistance of the weathering steel; the Cu does not remarkably reduce the plasticity of the weathering steel, and simultaneously improves the strength and the toughness of the weathering steel; re is beneficial to crystallizing the weathering steel matrix and improving the mechanical property and the weathering property of the weathering steel; meanwhile, Re is beneficial to improving the toughness, weldability and processability of the weathering steel.

Further, Mn is beneficial to improving the hardness and strength of ferrite and austenite and improving the stability of austenite; c is beneficial to expanding an austenite phase region and improving the strength and hardness of the weathering steel; ti is beneficial to making the structure of the weathering steel compact and refining crystal grains; nb is beneficial to refining crystal grains, reduces the overheating sensitivity of the weathering steel and improves the atmospheric corrosion resistance of the weathering steel; v is beneficial to refining crystal grains and improving the strength and toughness of the weathering steel.

The test result of the embodiment shows that the yield strength of the weathering steel containing rare earth is 411.82-509.71 MPa, the tensile strength is 567.69-713.98 MPa, the elongation is 34.56-49.36%, and the density is 6.58-7.52 g/cm³Good strength, plasticity and low density; the weight loss in the sodium bisulfite aqueous solution of 360h is 1.98-3.09 mg/cm²And has excellent weather resistance.

The invention also provides a preparation method of the rare earth-containing weathering steel, which comprises the following steps: smelting a raw material of high-aluminum weathering steel and then cooling to obtain an ingot; and carrying out homogenization treatment and rolling deformation treatment on the cast ingot in sequence to obtain the rare earth-containing weathering steel. In the invention, the crystal grains are refined through violent deformation in the rolling deformation treatment process and are elongated along the rolling direction, which is favorable for effectively improving the mechanical property of the weathering steel containing rare earth on the basis of ensuring the weathering resistance. The method provided by the invention is simple, and subsequent treatments such as annealing and the like are not needed after the rolling deformation treatment, so that the method is simple and easy to implement.

Drawings

FIG. 1 is a metallographic optical micrograph of a weathering steel containing rare earth obtained in example 1;

FIG. 2 is a metallographic optical micrograph of a weathering steel containing rare earth obtained in example 2;

FIG. 3 is a metallographic optical micrograph of a weathering steel containing rare earth obtained in example 3;

FIG. 4 is a metallographic optical micrograph of a weathering steel containing rare earth obtained in example 4;

FIG. 5 is a metallographic optical micrograph of a weathering steel containing rare earth obtained in example 5;

fig. 6 is a dimensional diagram of a uniaxial tensile specimen for tensile property testing.

Detailed Description

The invention provides rare earth-containing weathering steel which comprises the following elements in percentage by mass:

4 to 11% of Al, 0.25 to 1.8% of Si, 0.01 to 0.35% of P, 0.1 to 0.55% of Cu, 0.025 to 0.55% of Re, and the balance of Fe.

In the invention, the rare earth-containing weathering steel comprises, by mass, 4-11% of Al, preferably 4.5-10.5%, more preferably 5-10%, and still more preferably 5.5-9.5%. In the invention, Al is beneficial to reducing the density of the weathering steel, refining crystal grains and improving the mechanical property and atmospheric corrosion resistance of the weathering steel.

In the invention, the rare earth-containing weathering steel comprises, by mass, 0.25-1.8% of Si, preferably 0.27-1.78%, more preferably 0.30-1.75%, and even more preferably 0.35-1.7%. In the invention, Si is beneficial to reducing the density of the weathering steel, reducing the anisotropy tendency of crystals and improving the strength and hardness of the weathering steel.

In the invention, the rare earth-containing weathering steel comprises, by mass, 0.01-0.35% of P, preferably 0.02-0.33%, more preferably 0.03-0.31%, and even more preferably 0.05-0.30%. In the invention, P is beneficial to improving the strength and hardness of the weathering steel and the atmospheric corrosion resistance of the weathering steel.

In the invention, the rare earth-containing weathering steel comprises, by mass, 0.1-0.55% of Cu, preferably 0.12-0.54%, more preferably 0.14-0.52%, and even more preferably 0.15-0.50%. In the invention, Cu is beneficial to improving the strength and the toughness of the weathering steel while not obviously reducing the plasticity of the weathering steel.

In the invention, the rare earth-containing weathering steel comprises, by mass, 0.025-0.55% of Re, preferably 0.025-0.53%, more preferably 0.025-0.50%, and even more preferably 0.025-0.45%. In the present invention, the Re is preferably one or more of Ce, La and Y. In the invention, Re is beneficial to crystallizing the weathering steel matrix and improving the mechanical property and the weathering property of the weathering steel; meanwhile, Re is beneficial to improving the toughness, weldability and processability of the weathering steel.

In the present invention, the rare earth-containing weathering steel preferably further includes one or more of the following elements in mass percent: mn, C, Ti, Nb and V.

In the invention, when the rare earth-containing weathering steel contains Mn, the rare earth-containing weathering steel preferably further contains Mn in an amount of more than 0 and not more than 35% by mass, more preferably 2-33%, still more preferably 3-30%, and still more preferably 10-26%. In the present invention, Mn is advantageous in increasing hardness and strength of ferrite and austenite and improving stability of austenite.

In the invention, when the rare earth-containing weathering steel contains C, the rare earth-containing weathering steel preferably further contains more than 0 and 0.6% by mass of C, more preferably 0.01-0.58%, still more preferably 0.03-0.55%, and further preferably 0.05-0.45%. In the invention, C is beneficial to expanding an austenite phase region and improving the strength and hardness of the weathering steel.

In the present invention, when the rare earth-containing weathering steel contains Ti, the rare earth-containing weathering steel preferably further contains more than 0 and 0.15% by mass or less of Ti, more preferably 0.001 to 0.14%, still more preferably 0.005 to 0.13%, and further more preferably 0.01 to 0.125%. In the invention, Ti is beneficial to densifying the structure of the weathering steel and refining grains.

In the invention, when the rare earth-containing weathering steel contains Nb, the rare earth-containing weathering steel preferably further includes more than 0 and 0.15% by mass of Nb, more preferably 0.01 to 0.14%, still more preferably 0.02 to 0.13%, and still more preferably 0.03 to 0.12%. In the invention, Nb is beneficial to refining crystal grains, reduces the overheating sensitivity of the weathering steel and improves the atmospheric corrosion resistance of the weathering steel.

In the present invention, when the rare earth-containing weathering steel contains V, the rare earth-containing weathering steel preferably further contains more than 0 and 0.15% by mass of V, more preferably 0.01 to 0.14%, still more preferably 0.02 to 0.13%, and still more preferably 0.03 to 0.12%. In the invention, V is beneficial to refining crystal grains and improving the strength and toughness of the weathering steel.

In the invention, the rare earth-containing weathering steel comprises the balance of Fe by mass percentage.

In the present invention, the structure of the rare earth-containing weathering steel preferably includes ferrite and/or austenite.

In the invention, the width of the structure of the rare earth-containing weathering steel is preferably 20-800 μm, and more preferably 25-700 μm.

The invention also provides a preparation method of the rare earth-containing weathering steel in the technical scheme, which comprises the following steps:

smelting a raw material containing rare earth weathering steel and then cooling to obtain an ingot;

and carrying out homogenization treatment and rolling deformation treatment on the cast ingot in sequence to obtain the rare earth-containing weathering steel.

In the present invention, unless otherwise specified, each component in the preparation method is a commercially available product well known to those skilled in the art.

The method comprises the steps of smelting a raw material containing the rare earth weathering steel and then cooling to obtain an ingot.

The invention has no special limitation on the specific sources and the addition amount of the raw materials of the rare earth-containing weathering steel, so as to obtain the rare earth-containing weathering steel meeting the chemical component requirements. Specifically, according to the composition of the actually obtained raw material alloy, the dosage of each raw material alloy is reasonably adjusted, and the components and dosage of the intermediate alloy are matched to obtain the rare earth-containing weathering steel meeting the chemical composition. In the present invention, the raw material of the rare earth-containing weathering steel preferably includes industrial pure iron, pure aluminum, silicon particles, ferrophosphorus, pure copper and rare earth particles, and preferably further includes one or more of electrolytic manganese flakes, carbon particles, pure titanium, pure niobium and pure vanadium.

In the present invention, the melting is preferably: mixing and melting raw materials containing the rare earth weathering steel, cooling, turning over the obtained alloy cast ingot, melting, cooling, and repeating for multiple times to obtain the cast ingot.

In the invention, the melting temperature is preferably 2100-2600 ℃, more preferably 2150-2580 ℃, more preferably 2200-2560 ℃ and further preferably 2350-2550 ℃. In the present invention, the number of times of melting is preferably not less than 6, and more preferably 7 to 9. In the invention, the time for each melting is preferably 3-5 min, more preferably 3.5-4.5 min, and still more preferably 3.7-4.5 min.

In the present invention, the melting is preferably vacuum arc melting. In the present invention, the melting apparatus is preferably a vacuum arc furnace, more preferably a non-consumable vacuum arc melting furnace. In the invention, the vacuum degree of the vacuum arc melting is preferably 0.04-0.08 MPa, and more preferably 0.045-0.075 MPa. In the present invention, the melting is preferably performed under an ionized gas condition. In the present invention, the ionized gas is preferably argon gas. According to the invention, the cavity of the smelting equipment is preferably vacuumized and then ionized gas is introduced. In the present invention, the evacuation is preferably performed to 4X 10^-3～7×10^-3Pa. In the invention, the introduction amount of the ionized gas is based on the usage amount of the ionized gas for electric arc melting. The method of firstly vacuumizing and then introducing ionized gas can avoid the weather-resistant steel elements from being oxidized to influence the quality of cast ingots during high-temperature smelting, and simultaneously, the elements are subjected to electric arc meltingThe process provides an ionized gas.

Before smelting, the raw materials of the rare earth-containing weathering steel are preferably cleaned. In the present invention, the liquid medium in the washing is preferably absolute ethanol. In the present invention, the cleaning method is preferably ultrasonic cleaning; the ultrasonic cleaning is not particularly limited in the present invention, and may be performed by ultrasonic cleaning known to those skilled in the art.

After washing, the present invention preferably air-dries the resulting cleaning material.

After the cast ingot is obtained, the cast ingot is subjected to homogenization treatment and rolling deformation treatment in sequence to obtain the rare earth-containing weathering steel.

In the invention, the homogenization treatment temperature is preferably 925-1100 ℃, more preferably 940-1075 ℃, and further preferably 950-1050 ℃; the heat preservation time is preferably 15-60 min, more preferably 25-50 min, and still more preferably 30-45 min. In the present invention, the temperature of the homogenization treatment is preferably obtained by raising the temperature to room temperature; the heating rate is preferably 5-15 ℃/min, more preferably 7-13 ℃/min, and still more preferably 9-11 ℃/min. In the present invention, the homogenization treatment apparatus is preferably a muffle furnace.

In the invention, the initial rolling temperature of the rolling deformation treatment is preferably 925-1100 ℃, more preferably 940-1075 ℃, and still more preferably 950-1050 ℃. In the present invention, the total deformation amount of the rolling deformation treatment is preferably 60 to 75%, and more preferably 62 to 73%. In the invention, the number of passes of the rolling deformation treatment is preferably 5-6; the amount of deformation per pass is preferably independently 10 to 15%, more preferably 11 to 14%. In the present invention, the rolling reduction per pass in the rolling deformation treatment is preferably 1.5 to 2.5mm, more preferably 1.7 to 2.3mm, and still more preferably 1.9 to 2.1 mm. In the invention, the thickness of the rare earth-containing weathering steel plate obtained after hot rolling is preferably 4.5-6 mm, more preferably 4.7-5.8 mm, and still more preferably 4.9-5.7 mm. In the present invention, the hot rolling apparatus is preferably a twin roll synchronous rolling mill; in an embodiment of the present invention, the hot rolling apparatus is preferably a 200-type twin-roll synchronous rolling mill.

The invention preferably maintains the temperature between two passes in the rolling deformation treatment. In the invention, the temperature of the heat preservation is preferably 925-1100 ℃, more preferably 940-1075 ℃, and further preferably 950-1050 ℃; the time is preferably 4 to 6min independently, and more preferably 4.5 to 5.5 min. In the present invention, the heat-retaining device is preferably a muffle furnace. In the invention, in the rolling deformation treatment process, the strong extrusion deformation causes the tissues to be elongated along the rolling direction, and the distortion energy generated by the severe deformation can be stored in the crystal grains, so that the weathering steel is promoted to be recrystallized in the heat preservation process between each rolling pass, the strength of the weathering steel is improved, and the obdurability of the weathering steel is further improved.

In the invention, the homogenization treatment and the rolling deformation treatment are combined, which is beneficial to eliminating the internal defects of the cast ingot caused by the water-cooled copper crucible after the smelting process, is beneficial to compacting the internal structure, and is beneficial to performing deformation strengthening on the weathering steel and improving the mechanical property.

In the invention, the rare earth-containing weathering steel has good mechanical properties and excellent weather resistance, and meets the use requirements of steel materials for industrial structures.

In order to further illustrate the present invention, the following examples are provided to describe the rare earth-containing weathering steel and the preparation method thereof in detail, but they should not be construed as limiting the scope of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The chemical components of the rare earth-containing weathering steel are as follows:

fe-4.5Al-3Mn-0.25Si-0.05P-0.2Cu-0.05Re, namely Al 4.5 percent, Mn 3 percent, Si0.25 percent, P0.05 percent, Cu 0.2 percent, Re 0.05 percent and the balance of Fe according to mass percentage; re is La;

according to the chemical composition of the rare earth-containing weathering steel, 91.8g of industrial pure iron, 4.5g of pure aluminum, 3g of electrolytic manganese sheet, 0.25g of silicon particles, 0.2g of ferrophosphorus, 0.2g of pure copper and 0.05g of rare earth particles are immersed in absolute ethyl alcohol, cleaned by ultrasonic waves and dried in the air;

mixing the obtained clean raw materials, placing in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace at a vacuum degree of 5 × 10^-3Carrying out vacuum arc melting under the conditions of Pa and argon with the pressure of 0.05MPa, wherein the melting temperature is 2400 ℃, cooling alloy liquid after each melting, turning over the obtained alloy ingot, then melting again for 4min each time, carrying out co-melting for 7 times, and cooling to obtain an ingot;

and placing the obtained cast ingot into a muffle furnace, heating to 1000 ℃ at the speed of 10 ℃/min, preserving heat for 40min, taking out, carrying out hot rolling on a 200-type double-roller synchronous rolling mill, wherein the starting rolling temperature of the hot rolling is 1000 ℃, the rolling passes of the hot rolling are 6 times, the reduction of each pass is 2mm, the deformation is 11 percent, the total deformation is 66 percent, and preserving heat for 5min at 1000 ℃ in the muffle furnace between the rolling passes of each pass to obtain the rare earth-containing weathering steel with the thickness of 5.5 mm.

Example 2

The chemical components of the rare earth-containing weathering steel are as follows:

fe-6Al-10Mn-0.1C-0.3Si-0.05P-0.2Cu-0.1Re-0.05Ti, namely Al 6%, Mn 10%, C0.1%, Si 0.3%, P0.05%, Cu 0.2%, Re 0.1%, Ti 0.05% and the balance of Fe in percentage by mass; re is La;

according to the chemical composition of the rare earth-containing weathering steel, 83.05g of industrial pure iron, 6g of pure aluminum, 10g of electrolytic manganese sheet, 0.1g of carbon particles, 0.3g of silicon particles, 0.2g of ferrophosphorus, 0.2g of pure copper, 0.1g of rare earth particles and 0.05g of pure titanium are immersed in absolute ethyl alcohol, cleaned by ultrasonic waves and dried in the air;

mixing the obtained clean raw materials, placing in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace at a vacuum degree of 5 × 10^-3Carrying out vacuum arc melting under the conditions of Pa and argon with the pressure of 0.05MPa, wherein the melting temperature is 2400 ℃, cooling alloy liquid after each melting, turning over the obtained alloy ingot, then melting again for 4min each time, carrying out co-melting for 7 times, and cooling to obtain an ingot;

and placing the obtained cast ingot into a muffle furnace, heating to 1000 ℃ at the speed of 10 ℃/min, preserving heat for 40min, taking out, carrying out hot rolling on a 200-type double-roller synchronous rolling mill, wherein the starting rolling temperature of the hot rolling is 1000 ℃, the rolling passes of the hot rolling are 6 times, the reduction of each pass is 2mm, the deformation is 11 percent, the total deformation is 66 percent, and preserving heat for 5min at 1000 ℃ in the muffle furnace between the rolling passes of each pass to obtain the rare earth-containing weathering steel with the thickness of 5.5 mm.

Example 3

The chemical components of the rare earth-containing weathering steel are as follows:

fe-7Al-19Mn-0.2C-0.4Si-0.1P-0.25Cu-0.1Re-0.05Ti-0.05Nb, namely Al 7%, Mn 19%, C0.2%, Si 0.4%, P0.1%, Cu 0.25%, Re 0.1%, Ti 0.05%, Nb 0.05% and the balance of Fe in percentage by mass; re is Y;

according to the chemical composition of the designed rare earth-containing weathering steel, 72.55g of industrial pure iron, 7g of pure aluminum, 19g of electrolytic manganese sheet, 0.2g of carbon particles, 0.4g of silicon particles, 0.4g of ferrophosphorus, 0.25g of pure copper, 0.1g of rare earth particles, 0.05g of pure titanium and 0.05g of pure niobium are immersed in absolute ethyl alcohol, cleaned by ultrasonic waves and dried in the air;

mixing the obtained clean raw materials, placing in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace at a vacuum degree of 5 × 10^-3Carrying out vacuum arc melting under the conditions of Pa and argon with the pressure of 0.05MPa, wherein the melting temperature is 2400 ℃, cooling alloy liquid after each melting, turning over the obtained alloy ingot, then melting again for 4min each time, carrying out co-melting for 7 times, and cooling to obtain an ingot;

and placing the obtained cast ingot into a muffle furnace, heating to 1000 ℃ at the speed of 10 ℃/min, preserving heat for 40min, taking out, carrying out hot rolling on a 200-type double-roller synchronous rolling mill, wherein the starting rolling temperature of the hot rolling is 1000 ℃, the rolling passes of the hot rolling are 6 times, the reduction of each pass is 2mm, the deformation is 11 percent, the total deformation is 66 percent, and preserving heat for 5min at 1000 ℃ in the muffle furnace between the rolling passes of each pass to obtain the rare earth-containing weathering steel with the thickness of 5.5 mm.

Example 4

The chemical components of the rare earth-containing weathering steel are as follows:

fe-9Al-26Mn-0.25C-0.4Si-0.15P-0.3Cu-0.2Re-0.1Ti-0.05Nb, namely Al 9%, Mn 26%, C0.25%, Si 0.4%, P0.15%, Cu 0.3%, Re 0.2%, Ti 0.1%, Nb 0.05% and the balance of Fe in percentage by mass; re is Y;

according to the chemical composition of the designed rare earth-containing weathering steel, 63.1g of industrial pure iron, 9g of pure aluminum, 26g of electrolytic manganese sheet, 0.25g of carbon particles, 0.4g of silicon particles, 0.6g of ferrophosphorus, 0.3g of pure copper, 0.2g of rare earth particles, 0.1g of pure titanium and 0.05g of pure niobium are immersed in absolute ethyl alcohol, cleaned by ultrasonic waves and dried in the air;

mixing the obtained clean raw materials, placing in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace at a vacuum degree of 5 × 10^-3Carrying out vacuum arc melting under the conditions of Pa and argon with the pressure of 0.05MPa, wherein the melting temperature is 2400 ℃, cooling alloy liquid after each melting, turning over the obtained alloy ingot, then melting again for 4min each time, carrying out co-melting for 7 times, and cooling to obtain an ingot;

and placing the obtained cast ingot into a muffle furnace, heating to 1000 ℃ at the speed of 10 ℃/min, preserving heat for 40min, taking out, carrying out hot rolling on a 200-type double-roller synchronous rolling mill, wherein the starting rolling temperature of the hot rolling is 1000 ℃, the rolling passes of the hot rolling are 6 times, the reduction of each pass is 2mm, the deformation is 11 percent, the total deformation is 66 percent, and preserving heat for 5min at 1000 ℃ in the muffle furnace between the rolling passes of each pass to obtain the rare earth-containing weathering steel with the thickness of 5.5 mm.

Example 5

The chemical components of the rare earth-containing weathering steel are as follows:

fe-10Al-33Mn-0.3C-0.45Si-0.2P-0.4Cu-0.25Re-0.1Ti-0.1Nb-0.1V, namely Al 10%, Mn 33%, C0.3%, Si 0.45%, P0.2%, Cu 0.4%, Re 0.25%, Ti 0.1%, Nb 0.1%, V0.1% and the balance of Fe by mass percentage; re is Y;

according to the chemical composition of the designed rare earth-containing weathering steel, 54.5g of industrial pure iron, 10g of pure aluminum, 33g of electrolytic manganese sheet, 0.3g of carbon particles, 0.45g of silicon particles, 0.8g of ferrophosphorus, 0.4g of pure copper, 0.25g of rare earth particles, 0.1g of pure titanium, 0.1g of pure niobium and 0.1g of pure vanadium are immersed in absolute ethyl alcohol, cleaned by ultrasonic waves and dried in the air;

mixing the obtained clean raw materials, and placing in a non-consumable placeIn a water-cooled copper crucible of a vacuum arc melting furnace, the degree of vacuum is 5X 10^-3Carrying out vacuum arc melting under the conditions of Pa and argon with the pressure of 0.05MPa, wherein the melting temperature is 2400 ℃, cooling alloy liquid after each melting, turning over the obtained alloy ingot, then melting again for 4min each time, carrying out co-melting for 7 times, and cooling to obtain an ingot;

and placing the obtained cast ingot into a muffle furnace, heating to 1000 ℃ at the speed of 10 ℃/min, preserving heat for 40min, taking out, carrying out hot rolling on a 200-type double-roller synchronous rolling mill, wherein the starting rolling temperature of the hot rolling is 1000 ℃, the rolling passes of the hot rolling are 6 times, the reduction of each pass is 2mm, the deformation is 11 percent, the total deformation is 66 percent, and preserving heat for 5min at 1000 ℃ in the muffle furnace between the rolling passes of each pass to obtain the rare earth-containing weathering steel with the thickness of 5.5 mm.

Metallographic optical microscopic observation is carried out on the weathering steel containing the rare earth obtained in examples 1 to 5, and the obtained metallographic optical fiber graph is shown in figures 1 to 5, wherein figure 1 is the metallographic optical microscopic graph of the weathering steel containing the rare earth obtained in example 1, figure 2 is the metallographic optical microscopic graph of the weathering steel containing the rare earth obtained in example 2, figure 3 is the metallographic optical microscopic graph of the weathering steel containing the rare earth obtained in example 3, figure 4 is the metallographic optical microscopic graph of the weathering steel containing the rare earth obtained in example 4, and figure 5 is the metallographic optical microscopic graph of the weathering steel containing the rare earth obtained in example 5.

As can be seen from fig. 1 to 5, the weathering steel containing rare earth obtained in example 1 was a pure ferrite structure; the weathering steel containing rare earth obtained in the embodiment 2 and the embodiment 3 has a ferrite and austenite dual-phase structure; the rare earth containing weathering steel obtained in example 4 and example 5 is pure austenite structure; the structure grain boundary of the weathering steel containing rare earth obtained in the embodiments 1-5 is clearly visible, which shows that the weathering steel containing rare earth obtained under the technical scheme provided by the invention does not have the phenomenon of grain boundary blurring caused by overburning.

Comparative example 1

The weathering steel comprises the following chemical components:

fe-0.8Mn-0.1C-0.5Si-0.15P-0.45Cu-0.05Ti, namely Mn 0.8%, C0.1%, Si 0.5%, P0.15%, Cu 0.45%, Ti 0.05%, and the balance Fe by mass percentage;

according to the chemical components of the designed weathering steel, 97.95g of industrial pure iron, 0.8g of electrolytic manganese sheet, 0.1g of carbon particles, 0.5g of silicon particles, 0.6g of ferrophosphorus, 0.45g of pure copper and 0.05g of pure titanium are soaked in absolute ethyl alcohol, cleaned by ultrasonic waves and dried in the air;

the remaining preparation method was the same as in example 1, to obtain weathering steel.

And (3) performing mechanical property test on the weathering steel containing the rare earth obtained in the examples 1-5 and the weathering steel obtained in the comparative example 1, wherein the test method comprises the following steps: the weather-resistant steel sheet was cut into a uniaxial tensile specimen in a bone bar shape by wire cutting, and the uniaxial tensile specimen was individually tested in accordance with GBT228-2002, and the dimensional chart of the uniaxial tensile specimen is shown in FIG. 6. During the test, at least 3 uniaxial tensile specimens were cut out of the samples of each example to ensure the reproducibility of the data, and the measurement was carried out using a room-temperature uniaxial tensile test with an Instron5982 Universal Material testing machine (manufacturer: Instron, USA) whose tensile displacement was monitored all the way with an extensometer, the tensile rate being set at 5X 10^-3s^-1. The mechanical property test results of the weathering steel containing rare earth obtained in examples 1 to 5 and the weathering steel obtained in comparative example 1 are shown in table 1.

TABLE 1 mechanical Property test results of examples 1 to 5 and comparative example 1

As shown in Table 1, the yield strength of the weathering steel containing rare earth is 411.82-509.71 MPa, the tensile strength is 567.69-713.98 MPa, the elongation is 34.56-49.36%, and the density is 6.58-7.52 g/cm³(ii) a Compared with the weathering steel provided by the comparison document 1, the yield strength is improved by 13.53-40.52%, the tensile strength is improved by 0.87-26.87%, the elongation is improved by 45.58-107.92%, the density is reduced by 6.35-18.06%, the mechanical property is better and lighter, and the weathering steel has a better engineering application prospect.

The corrosion resistance of the weathering steel containing the rare earth obtained in the examples 1-5 and the weathering steel obtained in the comparative example 1 is tested, and the test method comprises the following steps: wire for weathering steelCutting and processing periodic infiltration corrosion samples with the size of 60mm multiplied by 40mm multiplied by 3mm, and cutting 5 samples from each weather-resistant steel plate to ensure the repeatability of the test; the test specimens were sanded to 800# using sand paper, rinsed and then blow-dried on their surface, and then periodically wetted into a corrosion test chamber (FL-65, Wuxi Shuzo & test instruments Co., Ltd.) according to TB/T2375-1993 in NaHSO at a concentration of 0.01mol/L₃And carrying out a periodic infiltration corrosion test in a solution environment, wherein the test standard of the periodic infiltration corrosion test is shown in table 2, the test period is 360h (15 days), so that the relevant data of the corrosion performance is obtained, and the test result is shown in table 3.

TABLE 2 test standards for periodic immersion corrosion testing

TABLE 3 Corrosion resistance test results of examples 1 to 5 and comparative example 1

	Weight loss (mg/cm)2)	Decrease in Corrosion weight loss in comparison with comparative example 1 (%)
			Example 1	3.09	82.10
Example 2	2.75	84.07
			Example 3	2.38	86.21
Example 4	2.12	87.72
			Example 5	1.98	88.53
Comparative example 1	17.26	/

As can be seen from Table 3, the weight loss of the rare earth-containing weathering steel provided by the invention in 360h of sodium bisulfite aqueous solution is 1.98-3.09 mg/cm²Comparative example 1 (weight loss of 17.26 mg/cm)²) Compared with the prior art, the rare earth-containing weathering steel provided by the invention has more excellent corrosion resistance.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.