阅读说明：本技术 一种泥沙输送管道用耐磨耐蚀钢板及其制备方法 (Wear-resistant corrosion-resistant steel plate for silt conveying pipeline and preparation method thereof ) 是由 麻衡 梁小凯 王中学 孙新军 童帅 何康 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种泥沙输送管道用耐磨耐蚀钢板及其制备方法,属于合金钢技术领域,该钢板的化学成分以质量百分数计包括：C：0.10-0.25％；Mn：0.5-1.5％；Si：0.2-0.5％；Cr：0.50-2.0％；Ni：0.8-2.0％；Mo：0.3-0.8％；Cu：0.5-2.0％；Sb：0.08-0.12％；Al：0.5-1.0％；S≤0.03％；P≤0.03％；余量为Fe和不可避免的杂质元素。本发明所述钢板的硬度范围HB375-HB475,在3.5％NaCl+5％H-(2)SO-(4)溶液或3.5％HCL溶液环境下,耐腐蚀性能可到常规NM450的4倍以上。本发明所述钢板焊接性能与传统耐磨钢相当,尤其适用于在海水或者酸性环境下泥沙输送管道用耐磨耐蚀钢的制备。(The invention disclosesA wear-resistant corrosion-resistant steel plate for a silt conveying pipeline and a preparation method thereof belong to the technical field of alloy steel, and the steel plate comprises the following chemical components in percentage by mass: c: 0.10 to 0.25 percent; mn: 0.5-1.5%; si: 0.2 to 0.5 percent; cr: 0.50-2.0%; ni: 0.8-2.0%; mo: 0.3 to 0.8 percent; cu: 0.5-2.0%; sb: 0.08-0.12%; al: 0.5-1.0%; s is less than or equal to 0.03 percent; p is less than or equal to 0.03 percent; the balance being Fe and unavoidable impurity elements. The steel plate has the hardness range of HB375-HB475, namely 3.5 percent of NaCl and 5 percent of H 2 SO 4 The corrosion resistance of the solution or the 3.5 percent HCL solution can be more than 4 times of that of the conventional NM 450. The welding performance of the steel plate is equivalent to that of the traditional wear-resistant steel, and the steel plate is particularly suitable for preparing the wear-resistant corrosion-resistant steel for the sediment conveying pipeline in seawater or an acidic environment.)

1. The wear-resistant corrosion-resistant steel plate for the sediment conveying pipeline is characterized by comprising the following chemical components in percentage by mass: c: 0.10 to 0.25 percent; mn: 0.5-1.5%; si: 0.2 to 0.5 percent; cr: 0.50-2.0%; ni: 0.8-2.0%; mo: 0.3 to 0.8 percent; cu: 0.5-2.0%; sb: 0.08-0.12%; al: 0.5-1.0%; s is less than or equal to 0.03 percent; p is less than or equal to 0.03 percent; the balance being Fe and unavoidable impurity elements.

2. The corrosion-resistant and wear-resistant steel plate for the sediment transport pipeline as claimed in claim 1, wherein the tensile strength of the acid corrosion-resistant steel plate is 1350MPa to 1450MPa, the hardness of the steel plate is HRB375 to 475, the elongation of the steel plate is 13% to 16%, the impact energy at-20 ℃ is 30J to 60J, and the impact energy is measured in the range of 3.5% NaCl + 5% H₂SO₄The corrosion resistance of the solution or the 3.5 percent HCL solution can reach more than 4 times of that of the conventional NM400 or NM 450.

3. A method for preparing a wear-resistant corrosion-resistant steel plate for a sediment transport pipeline as claimed in claim 1 or 2, comprising the steps of:

1) continuously casting the plate blank after molten steel is subjected to molten iron desulfurization, converter or electric furnace smelting and external refining treatment, wherein the continuous casting drawing speed is 0.8-1.3m/min, the heating temperature is 1100-1300 ℃, and the heat preservation time is 2-5 hours;

2) heating, rolling, cooling and heat treatment are sequentially carried out after the slab is continuously cast, wherein the heating temperature is 1100-1300 ℃, and the heat preservation time is 2-5 hours; 4-7 times of rough rolling and 7-14 times of finish rolling, wherein the finish rolling temperature is 830-880 ℃; the heat treatment includes quenching and tempering.

4. The manufacturing method according to claim 3, wherein the thickness of the slab in the step 1) is 5-50 mm.

5. The method as claimed in claim 3, wherein the cooling in step 2) comprises air cooling or accelerated cooling after rolling, and the final cooling temperature is 300-700 ℃.

6. The preparation method according to claim 3, wherein the quenching heating temperature in the step 2) is 880-900 ℃, the quenching heat preservation time is 30-60 min, the tempering temperature is 150-200 ℃, and the tempering heat preservation time is 40-60 min.

Technical Field

The invention belongs to the technical field of alloy steel, and particularly relates to a wear-resistant corrosion-resistant steel plate for a silt conveying pipeline and a preparation method thereof.

Background

The silt conveying pipeline is affected by complex environment (such as seawater corrosion, complex soil quality of sand mixed pebbles and the like), and the corrosion, abrasion and failure are serious. Frequent replacement of the pipeline leads to reduction of construction efficiency and improvement of construction cost. In order to improve the wear resistance of pipelines and prolong the service life of the pipelines, a corrosion-resistant wear-resistant steel which is resistant to seawater and acidic environment corrosion, high in hardness, capable of being formed and welded is urgently needed.

Disclosure of Invention

In view of the above, the present invention aims to provide a martensite wear-resistant steel plate resistant to corrosion of seawater and an acidic environment and a preparation method thereof, so as to solve the problem that the wear resistance and the corrosion resistance of the steel plate cannot be considered at the same time in the prior art.

In order to achieve the purpose, the invention provides a wear-resistant corrosion-resistant steel plate for a silt conveying pipeline, namely, the chemical components of the martensite wear-resistant steel plate resisting corrosion and wear comprise the following components in percentage by mass: c: 0.10 to 0.25 percent; mn: 0.5-1.5%; si: 0.2 to 0.5 percent; cr: 0.50-2.0%; ni: 0.8-2.0%; mo: 0.3 to 0.8 percent; cu: 0.5-2.0%; 0.08 to 0.12 percent of Sb; al: 0.5-1.0%; s is less than or equal to 0.03 percent; p is less than or equal to 0.03 percent; (ii) a The balance of iron and inevitable impurity factors;

preferably, the wear-resistant corrosion-resistant steel plate for the sediment transport pipeline comprises the following chemical components in percentage by mass: 0.13 to 0.20 percent; mn: 0.5-1.0%; si: 0.2 to 0.5 percent; cr: 0.50-1.0%; ni: 0.8 to 1.0 percent; mo: 0.3 to 0.5 percent; cu: 0.5-1.0%; 0.08 to 0.12 percent of Sb; al: 0.5-1.0%; s is less than or equal to 0.03 percent; p is less than or equal to 0.03 percent; the balance being Fe and unavoidable impurity elements.

The action and the proportion of each element of the invention are as follows:

carbon: the hardenability of the steel is improved, the strong solid solution strengthening effect is achieved, and the strength and the hardness of the martensitic steel are obviously improved; according to the capability of the current processing and bending equipment, the carbon content is selected to be 0.15-0.25%, and the surface hardness of the steel plate after heat treatment is HB 400-450.

Silicon: one of the deoxidizing elements in the steel has a certain solid solution strengthening effect, but the excessive silicon is unfavorable for the toughness and the welding performance of the steel. In combination with the above considerations, the silicon content of the steel of the invention ranges from 0.20 to 0.50 wt.%.

Manganese: obviously improves the hardenability of the steel and has certain solid solution strengthening effect. However, when the manganese content is high, the tendency to segregate in the cast slab increases, the susceptibility to temper embrittlement of the steel increases, and the welding performance is also unfavorable. The manganese content of the steel of the invention ranges from 0.50 to 1.00 wt.%.

Molybdenum: the hardenability of the steel is obviously improved, the temper brittleness is reduced, and the ions can automatically supplement gaps formed by point corrosion of Cl (chlorine) ions to the steel in seawater to form a compact protective layer so as to prevent the point corrosion from developing to the depth. Thereby playing a role of resisting pitting corrosion. The molybdenum content is controlled according to the invention in the range of 0.30-0.8 wt.%, preferably 0.30-0.50 wt.%.

Chromium: the hardenability and the resistance to corrosive wear of the steel are improved, but too high chromium reduces the workability and weldability, the invention controlling the chromium content in the range of 0.50-1.0 wt.%.

Nickel: the hardenability of the steel is improved, the low-temperature toughness is obviously improved, and the corrosion resistance of the steel is improved. The nickel content is controlled in the range of 0.8-1.0 wt.% in the invention.

Copper: the hardenability and the corrosion resistance of the steel are improved, and the wear resistance can be obviously improved under the corrosive wear environment. The copper content of the steel of the invention is controlled in the range of 0.5-1.0 wt.%.

Antimony: sb and Cr are added in a compounding manner to be enriched in the rust layer in a synergic manner, and a compact oxide film which is higher than a matrix by times and rich in elements such as Sb and Cr is formed, so that the transmission of etching ions is obviously hindered, and the corrosion environment with coexisting sulfate radicals and chloride ions is more resistant; however, excessive antimony content may adversely affect hot workability, weldability, and toughness of the steel sheet, and the antimony content of the steel of the present invention is controlled to be in the range of 0.08 to 0.12 wt.%.

Aluminum: can react with oxygen in the air to generate aluminum oxide, and is corrosion-resistant and corrosion-resistant. The invention controls the aluminum content to be in the range of 0.5-1.0 wt.%.

Phosphorus and sulfur as impurity elements seriously damage the toughness and plasticity of steel, and the content is respectively controlled to be less than or equal to 0.005 wt% of S and less than or equal to 0.015 wt% of P.

The invention provides a preparation method of a wear-resistant corrosion-resistant steel plate, which sequentially comprises the following steps: continuously casting (die casting) a plate blank after the molten steel is subjected to KR method desulfurization, converter or electric furnace smelting and external refining treatment; wherein the continuous casting step comprises: the continuous casting speed is 0.8-1.3m/min, the heating temperature is 1100-1300 ℃, and the heat preservation time is 2-5 hours; the thickness of the plate blank is 5-50 mm.

2) After continuously casting (die casting) a slab, sequentially carrying out heating, controlled rolling, controlled cooling and heat treatment, wherein the hot rolling slab rolling step comprises the following steps: and (3) reheating the slab, namely heating the slab in a heating furnace after the continuous casting slab or the cast ingot is cogging, wherein the heating temperature is 1100-1300 ℃, and the time is 2-5 hours. The production method is characterized by adopting a heavy and medium plate mill for rolling production, and the rolling steps comprise: 4-8 passes of rough rolling and 7-14 passes of finish rolling, wherein the finish rolling temperature of the finish rolling is 830-880 ℃, the cooling comprises air cooling or accelerated cooling after rolling, and the finish cooling temperature is 300-700 ℃. Straightening the steel plate in the air cooling process or after accelerated cooling.

And (3) carrying out heat treatment on the steel plate, including quenching and tempering.

And (3) quenching and heating at 880-900 ℃ for 30-60 minutes, and heating the steel plate and then performing water quenching. The overhigh heating temperature coarsens austenite grains, and reduces the toughness and plasticity of the steel; too low heating temperature significantly lowers the hardenability of steel and the core hardness of thick steel plate, which is not good for wear resistance.

The tempering temperature is 150-.

Compared with the prior art, the invention has the following beneficial effects:

through the process, the method is suitable for preparing the wear-resistant and corrosion-resistant steel for the sediment conveying pipeline in the seawater or acidic environment. The matrix structure of the wear-resistant steel is lath martensite, the tensile strength of the corrosion-resistant martensite wear-resistant steel plate is 1250MPa-1450MPa, the hardness is HRB375-475, preferably, the hardness range of the steel plate is HB400-HB450, the elongation is 6% -13%, the impact energy at the temperature of minus 20 ℃ is 30J-60J, and the work efficiency is 3.5% NaCl + 5% H₂SO₄The corrosion resistance of the solution or the 3.5 percent HCL solution can be more than 4 times of that of the conventional NM400 or NM 450; the machining performance and the welding performance are excellent, and the manufacturing requirements of the silt conveying pipeline can be met.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Example 1

The chemical composition of the invention is C: 0.15 percent; mn: 0.55 percent; si: 0.25 percent; cr: 0.65 percent; ni: 0.88 percent; mo: 0.35 percent; cu: 0.58 percent; sb: 0.10 percent; al: 0.85 percent; s is less than or equal to 0.03 percent; p is less than or equal to 0.03 percent; the manufacturing process comprises the following steps: KR desulfurization, converter smelting, LF refining, RH refining, slab continuous casting, rolling by adopting a heavy and medium plate mill, heating by a heating furnace at 1200 ℃, finish rolling at 860 ℃, rolling at 30mm in thickness, and air cooling after rolling. The heat treatment process comprises the following steps: austenitizing temperature is 880 ℃, heat preservation time is 1 hour, water quenching is carried out to room temperature, and then tempering is carried out for 2 hours at 200 ℃ and air cooling is carried out to room temperature.

Example 2

The chemical composition of the invention is C: 0.18 percent; mn: 0.72 percent; si: 0.33 percent; cr: 0.93 percent; ni: 0.80 percent; mo: 0.35 percent; cu: 0.65 percent; sb: 0.10 percent; al: 0.78%; s is less than or equal to 0.03 percent; p is less than or equal to 0.03 percent; the manufacturing process comprises the following steps: KR desulfurization, converter smelting, LF refining, RH refining, slab continuous casting, rolling by adopting a heavy and medium plate mill, heating by a heating furnace at 1200 ℃, finish rolling at 860 ℃, rolling at the thickness of 16mm, and air cooling after rolling. The heat treatment process comprises the following steps: austenitizing temperature is 880 ℃, heat preservation time is 0.5 hour, water quenching is carried out to room temperature, then tempering is carried out for 1 hour at 200 ℃, and air cooling is carried out to room temperature.

The embodiment of the invention is compared with NM400 and NM450 mechanical properties and corrosion resistance

Conventional technical knowledge in the art can be used for the details which are not described in the present invention.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.