Wear-resistant high manganese steel and method for manufacturing the same

Abstract

This invention discloses a wear-resistant high-manganese steel and its preparation method. The steel comprises the following chemical components by mass percentage: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities. This invention achieves an effective balance between wear resistance and toughness through the synergistic effect of these elements. After impact work hardening, the material reaches a hardness of 40-50 HRC and an impact toughness of 208-234 J / cm². 2 The service life is 30%-100% longer than that of traditional high manganese steel, and it has excellent corrosion resistance and processability, and is economical in cost. This wear-resistant high manganese steel is suitable for medium and high stress impact abrasive wear conditions and can be widely used to manufacture wear-resistant parts such as ball mill liners, crusher jaw plates, and excavator bucket teeth, and has important industrial application value.

Description

Technical Field

[0001] This invention relates to the field of metal wear-resistant materials technology, specifically to a wear-resistant high-manganese steel and its preparation method. Background Technology

[0002] Wear-resistant steel, as a special type of steel, originated around the latter half of the 19th century. In 1883, the Englishman Robert Hadfield first obtained a patent for high-manganese steel, which has a history of more than 100 years. High-manganese steel is a type of wear-resistant steel with high carbon and manganese content. This ancient steel with more than a hundred years of history has the advantages of strong work hardening ability under high impact abrasive wear conditions, as well as good toughness and plasticity, and easy production process. At present, it is still the most widely used type of wear-resistant steel, especially in mining and other sectors.

[0003] For example, Chinese invention patent application number CN202510245758.X discloses a high-wear-resistant and high-toughness high-manganese medium-chromium steel, its preparation method and application. The high-manganese medium-chromium steel, by mass percentage, includes the following group: C: 0.9~1.2%, Mn: 12~14%, Cr: 3~5%, Si: 0.3~0.8%, S: 0.04%, P: 0.05%, V: 0.1~0.15%, Ti: 0.08~0.15%, with the remainder being iron and unavoidable impurities.

[0004] For example, Chinese invention patent application number CN202411736466.8 discloses a high-manganese steel for crusher liners and its heat treatment method. The mass percentage content of each component of the high-manganese steel for crusher liners includes C 1.15-1.45%, Mn 17-19%, Cr 2.5-5.0%, Mo 0.45-0.6%, Ti 0.2-0.4%, Re 0.02-0.06%, P 0.045%, and S 0.045%. The heat treatment method for the high-manganese steel for crusher liners includes water quenching and dispersion treatment.

[0005] For example, Chinese invention patent application number CN202211200706.3 discloses a high-manganese steel with good wear resistance, the composition and wt% of which are: C: 0.7~1.2%, Mn: 13.0~21.0%, Cr: 3.0~4.0%, Al: 1.0~1.5%, Si: 0.05~0.3%, Cu: 0.1~0.5%, S0.015%, P0.005%; the production method is as follows: smelting and casting into billets; heating the billets; hot rolling; annealing after cooling to room temperature; cold rolling to the product thickness at room temperature; reverse phase transformation annealing; cooling; cooling to room temperature.

[0006] Currently, high-manganese steel is commonly used for wear-resistant parts in Chinese mines. It can exhibit significant work hardening under high impact loads. However, during operation, due to continuous stress and collisions over long periods, localized areas of the working surface of the wear-resistant parts will experience accelerated oxidation and corrosion due to sudden temperature increases, leading to surface deformation and damage. To improve its service life, wear-resistant parts not only need sufficient hardness and heat resistance but also excellent toughness and deformation resistance. Existing high-manganese steel cannot meet the requirements of actual working conditions, thus limiting its application. Based on the above-mentioned technical problems in the existing technology, this invention provides a wear-resistant high-manganese steel and its preparation method. Summary of the Invention

[0007] To address the aforementioned technical problems in existing technologies, this invention provides a wear-resistant high-manganese steel and its preparation method. The wear-resistant high-manganese steel of this invention increases the content of Mn and Cr compared to traditional high-manganese steel. Mn forms various carbides such as (Fe,Mn)3C and Mn7C3 in the steel matrix, significantly improving the strength and impact toughness of the ultra-high-manganese steel. Cr is an important component of steel; Cr can form dispersed second-phase particles in the crystal structure, thereby reducing carbide precipitation, changing the morphology and distribution of carbides, and improving the phase transformation hardening effect and yield strength. The wear-resistant high-manganese steel of this invention is suitable for manufacturing wear-resistant parts under medium-to-high stress impact abrasive wear conditions, such as liners for medium and large ball mills, jaw plates for jaw crushers, crushing walls and grinding mill walls for cone crushers.

[0008] The present invention adopts the following technical solution:

[0009] The wear-resistant high-manganese steel of this invention comprises the following chemical composition by weight percentage: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities.

[0010] Furthermore, the wear-resistant high-manganese steel of the present invention comprises the following chemical composition by weight percentage: C: 0.8%-1.15%; Mn: 14%-19%; Si≤0.045%; S: 0.004%-0.005%; P: 0.035%-0.037%; Cr: 5.0%-8.0%; B: 0.006%-0.007%; Re: 0.022%-0.026%, with the balance being Fe and unavoidable impurities.

[0011] Furthermore, the wear-resistant high-manganese steel of the present invention comprises, by mass percentage, the following chemical components: C: 1.15%, Mn: 13.5%, Cr: 5.05%, Si: 0.45%, S: 0.005%, P: 0.037%, B: 0.006%, Re: 0.022%, with the balance being Fe and unavoidable impurities.

[0012] This invention also provides a method for preparing wear-resistant high-manganese steel, comprising:

[0013] Step 1: Melt carbon steel, ferromanganese, ferrochrome, and ferrosilicon alloy raw materials in a medium-frequency induction furnace to form molten steel;

[0014] Step 2: After the furnace charge is completely melted, deoxidation is performed, and ferroboron and rare earth alloys are added to adjust the content of each element. The percentage content by mass is as follows: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities.

[0015] Step 3: Pour molten steel into a ladle, purify the ladle with argon, let it stand, and then pour the casting at a temperature of 1400℃-1450℃ to obtain the casting.

[0016] Step 4: Perform solution treatment on the casting at a temperature of 1020℃-1120℃, hold at the temperature and immediately quench in water to room temperature; then perform low-temperature tempering at a temperature of 200℃-250℃, hold at the temperature for 4-8 hours and then air cool to room temperature.

[0017] Furthermore, in step 2, the deoxidation operation is carried out by inserting aluminum wires for deep deoxidation when the furnace temperature reaches 1580℃-1600℃.

[0018] The addition of ferroborone and rare earth alloys should be done 8-10 minutes before tapping.

[0019] Furthermore, in step 3, the argon blowing purification time is 2-4 minutes.

[0020] Furthermore, in step 4, the heat preservation time of the solution treatment is determined according to the effective thickness of the casting, with 1 hour of heat preservation for every 25mm of thickness.

[0021] Compared with the prior art, the superior effects of the present invention are as follows:

[0022] 1. The wear-resistant high-manganese steel of this invention, through optimizing the composition ratio of C, Mn, Cr, B, and Re, forms a multi-component strengthening mechanism. C synergistically forms (Fe, Mn)3C and Mn7C3 hard carbides with Mn and Cr, Cr forms dispersed hard carbides with C, B forms iron boride and manganese boride wear-resistant compounds with Fe, Mn, and Cr, and Re refines the grains and enhances the work hardening ability. Under the multiple effects, the wear resistance of the material is significantly better than that of traditional high-manganese steel. According to the data of the examples, the wear-resistant high-manganese steel prepared by this invention has a service life that is 30% to 100% longer than that of traditional high-manganese steel under the working conditions of a 600x900 tooth plate in a silicon mine. After impact work hardening, the hardness reaches 0 to 50 HRC, which is much higher than the 30 to 35 HRC of traditional high-manganese steel.

[0023] 2. The wear-resistant high-manganese steel of this invention, through precise control of the Mn content, ensures the formation of a stable austenitic structure, avoiding grain coarsening and reduced toughness caused by excessive Mn; simultaneously, Re refines the grains and Cr improves the carbide morphology, enabling the material to achieve an impact toughness of 208~234 J / cm. 2 It is significantly higher than the 144~165 J / cm of traditional high-manganese steel. 2 This effectively reduces the risk of breakage of wear-resistant parts under high-impact conditions and solves the contradiction in existing technologies that "wear-resistant parts are brittle and tough parts are not wear-resistant."

[0024] 3. The wear-resistant high-manganese steel of the present invention has a dispersed distribution of second-phase particles formed by Cr element, which effectively reduces carbide precipitation and optimizes its morphology distribution. Combined with the grain refinement effect of Re, it greatly improves the phase transformation hardening effect and yield strength of the material. Mn and Si synergistically improve hardenability and obtain a uniform microstructure, enabling the material to be rapidly processed and hardened under continuous stress and collision conditions. The hardened layer has strong stability and avoids local deformation failure.

[0025] 4. The wear-resistant high-manganese steel of the present invention has a reasonable ratio of Cr element, which can promote the formation of dense austenite grains and improve the corrosion resistance of the material. At the same time, the synergistic effect of Cr and B can inhibit the oxidation corrosion of the working surface of wear-resistant parts caused by instantaneous high temperature, significantly reduce the surface damage rate under harsh working conditions, and extend the service life of the material under the combined working conditions of impact + wear + corrosion.

[0026] 5. The wear-resistant high manganese steel of this invention has mechanical properties that are suitable for the core working conditions of medium- and high-stress impact abrasive wear. It can be widely used in the manufacture of various wear-resistant parts such as ball mill liners, hammer crusher hammers, jaw crusher jaw plates, cone crusher grinding bowls / crushing walls, and excavator bucket teeth / bucket walls. It solves the problems of traditional high manganese steel being prone to wear, breakage, and short service life under complex working conditions. It is suitable for the stringent use requirements of industries such as mining, metallurgy, and building materials. Its application scope covers all scenarios of traditional high manganese steel, and it performs better under more severe working conditions.

[0027] 6. The wear-resistant high-manganese steel of the present invention, by strictly controlling the content range of Mn and Cr, takes into account both the mechanical properties and the processability of the material; the preparation process adopts medium-frequency furnace melting, conventional casting and heat treatment process, which does not require complex equipment, has strong process stability, is suitable for industrial mass production, and solves the problems of high processing difficulty and high production cost of some high alloy wear-resistant steels. Detailed Implementation

[0028] To better understand the above-mentioned objectives, features and advantages of the present invention, the present invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0029] The wear-resistant high-manganese steel, by mass percentage, comprises the following chemical composition: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities.

[0030] The carbon content affects the hardness and wear resistance of high manganese steel. An appropriate amount of carbon helps to form hard carbides, enhancing wear resistance, and carbon can maintain the austenitic structure and ensure the hardness of high manganese steel. However, too much carbon will reduce the toughness of the material. Therefore, the carbon content should be controlled between 0.6% and 1.2%.

[0031] The Cr content can enhance corrosion resistance and wear resistance, promote the formation of dense austenite grains, and form hard carbides with C. However, excessive Cr not only increases material cost but also increases welding difficulty and causes cracking. Furthermore, excessive Cr promotes uneven distribution of hard phases, affecting the overall mechanical properties of the material. Cr also complicates phase transformation behavior during heat treatment, resulting in poor material controllability. Therefore, the Cr content is controlled between 3.0% and 10.0%.

[0032] Si can promote the formation of austenite and work with Mn to improve the hardenability of materials, helping to obtain a uniform microstructure and improve the overall performance of materials. However, excessive silicon content will increase the hardness and brittleness of materials, affect the toughness and plasticity of materials, and lead to poor material forming performance. Therefore, the content of Si element is controlled at 0.4%-0.8%.

[0033] Boron (B) increases the density and hardness of steel and strengthens crystal interfaces. As a chemically active element, B forms compounds with C (B4C), Mn (MnB), BCr (BCr), Si (SiB6), and Fe (BFe), further enhancing the steel's wear resistance and corrosion resistance. However, excessive B content in the wear-resistant high-manganese steel can lead to the formation of a ternary eutectic composed of borides (Fe2B), cementite (Fe3(C,B)), and austenite, distributed along the austenite grain boundaries, significantly reducing the high-manganese steel's plasticity and toughness. Therefore, the B content is controlled at 0.005%-0.02%.

[0034] In the high-carbon, high-manganese austenitic steel of the present invention, the addition of rare earth element Re can effectively refine the grains, improve the yield strength and work hardening ability of the material, and thus improve the wear resistance of the steel. The mass percentage content of Re element is controlled between 0.02% and 0.03%.

[0035] As the main alloying element in high manganese steel, Mn with a concentration exceeding 13% can form an austenitic structure, providing good toughness and ductility. Mn can also combine with sulfur to form MnS, avoiding brittleness caused by sulfides. Excessive Mn content increases the hardness and brittleness of the material, affecting its deformation ability and making processing difficult. Furthermore, too much Mn can lead to coarse grains, weakening the toughness and plasticity of the material. Therefore, the Mn content is controlled at 14%-19%.

[0036] In a specific example, the wear-resistant high-manganese steel of the present invention comprises the following chemical composition by mass percentage: C: 0.8%-1.15%; Mn: 14%-19%; Si≤0.045%; S: 0.004%-0.005%; P: 0.035%-0.037%; Cr: 5.0%-8.0%; B: 0.006%-0.007%; Re: 0.022%-0.026%, with the balance being Fe and unavoidable impurities.

[0037] In a specific example, the wear-resistant high-manganese steel of the present invention comprises the following components by mass percentage: C: 1.15%, Mn: 13.5%, Cr: 5.05%, Si: 0.45%, S: 0.005%, P: 0.037%, B: 0.006%, Re: 0.022%, with the balance being Fe and unavoidable impurities.

[0038] This invention also provides a method for preparing wear-resistant high-manganese steel, comprising:

[0039] Step 1: Melt carbon steel, ferromanganese, ferrochrome, and ferrosilicon alloy raw materials in a medium-frequency induction furnace to form molten steel;

[0040] Step 2: After the furnace charge is completely melted, deoxidation is performed, and ferroboron and rare earth alloys are added to adjust the content of each element. The percentage content by mass is as follows: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities.

[0041] Step 3: Pour molten steel into a ladle, purify the ladle with argon, let it stand, and then pour the casting at a temperature of 1400℃-1450℃ to obtain the casting.

[0042] Step 4: Perform solution treatment on the casting at a temperature of 1020℃-1120℃, hold at the temperature and immediately quench in water to room temperature; then perform low-temperature tempering at a temperature of 200℃-250℃, hold at the temperature for 4-8 hours and then air cool to room temperature.

[0043] In some specific embodiments, the deoxidation operation described in step 2 is to insert aluminum wires for deep deoxidation when the furnace temperature reaches 1580℃-1600℃.

[0044] The addition of ferroborone and rare earth alloys should be done 8-10 minutes before tapping.

[0045] In some specific embodiments, the argon blowing purification time in step 3 is 2-4 minutes.

[0046] Furthermore, in step 4, the heat preservation time of the solution treatment is determined according to the effective thickness of the casting, with 1 hour of heat preservation for every 25mm of thickness.

[0047] Specific Example 1

[0048] The wear-resistant high-manganese steel comprises, by mass percentage, the following components: C: 1.15%, Mn: 13.5%, Cr: 5.05%, Si: 0.45%, S: 0.005%, P: 0.037%, B: 0.006%, Re: 0.022%, with the remainder being iron and unavoidable impurities;

[0049] According to the mass percentage, various elemental materials are added to the medium-frequency induction furnace for smelting. High-quality carbon steel, high-carbon ferromanganese, medium-carbon ferromanganese, high-carbon ferrochrome, and ferroboron are used as raw materials. First, carbon steel is placed in the medium-frequency induction furnace. After the carbon steel melts, high-carbon ferromanganese and high-carbon ferrochrome are added, with the material block size being 50-80mm. When the furnace charge in the medium-frequency induction furnace is cleared and the furnace temperature reaches 1580-1600℃, aluminum wire is inserted deep into the furnace for deoxidation. At this time, the surface of the molten metal is covered with a heating and insulating covering agent to isolate it from the outside air. The resulting cast wear-resistant high-manganese steel is then calmed for 8-12 minutes to allow oxides and inclusions to float to the surface. During this period, the content of each element is adjusted using medium-carbon ferromanganese and high-carbon ferrochrome. Eight to ten minutes before the start of the induction furnace, weighed ferroboron is added to the furnace. When the molten steel reaches a melting temperature of 1580-1650℃, the molten steel is poured into a ladle. After exiting the induction furnace, argon is blown into the ladle to purify the molten steel, which is then allowed to stand for 2-4 minutes. The pouring temperature is 1400-1450℃ to obtain wear-resistant high-manganese steel castings. The solution treatment temperature of the castings is 1050-1120℃. After the castings are held at this temperature, they are removed from the heat treatment resistance furnace (380V, maximum temperature 1200℃) and immediately placed in water for high-temperature quenching at 1030-1080℃. The castings are then cooled to room temperature before being removed from the water. Finally, the castings are placed in the heat treatment resistance furnace for low-temperature tempering at 200-250℃ for 4-8 hours. After being removed from the furnace, they are air-cooled to room temperature.

[0050] Specific Example 2

[0051] Compared with Example 1, Example 2 differs in that the wear-resistant high manganese steel comprises the following components by mass percentage: C: 1.05%, Mn: 14.1%, Cr: 6.2%, Si: 0.48%, S: 0.005%, P: 0.036%, B: 0.007%, Re: 0.025%, with the remainder being iron and unavoidable impurities.

[0052] Specific Example 3

[0053] Compared with Example 1, the difference is that the wear-resistant high manganese steel, by mass percentage, includes the following components: C: 0.82%, Mn: 14.6%, Cr: 7.9%, Si: 0.47%, S: 0.005%, P: 0.036%, B: 0.006%, Re: 0.026%, with the remainder being iron and unavoidable impurities.

[0054] Comparative example, conventional high-manganese steel: C: 1.20%, Mn: 12.5%, Cr: 1.82%, Si: 0.46%, S: 0.005%, P: 0.035%. The initial hardness, hardness after impact work hardening, impact toughness, and performance of the three wear-resistant high-manganese steel specimens prepared in Examples 1, 2, and 3 were tested. The results are shown in Table 1.

[0055] Table 1

[0056]

[0057] The comparative data above shows that the high-manganese medium-chromium steel prepared by this invention, through optimization of alloy composition and preparation process, has successfully achieved an effective balance between wear resistance and toughness, providing a new solution for the application of metal wear-resistant materials under harsh working conditions.

[0058] This invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims.

Claims

1. A wear-resistant high-manganese steel, characterized in that, Based on mass percentage, it comprises the following chemical components: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities.

2. The wear-resistant high-manganese steel according to claim 1, characterized in that, The chemical composition, by mass percentage, comprises the following: C: 0.8%-1.15%; Mn: 14%-19%; Si ≤0.045%; S: 0.004%-0.005%; P: 0.035%-0.037%; Cr: 5.0%-8.0%; B: 0.006%-0.007%; Re: 0.022%-0.026%, with the balance being Fe and unavoidable impurities.

3. The wear-resistant high-manganese steel according to claim 1, characterized in that, The chemical composition, by mass percentage, comprises the following components: C: 1.15%, Mn: 13.5%, Cr: 5.05%, Si: 0.45%, S: 0.005%, P: 0.037%, B: 0.006%, Re: 0.022%, with the balance being Fe and unavoidable impurities.

4. A method for preparing wear-resistant high-manganese steel, applied to the wear-resistant high-manganese steel as described in any one of claims 1 to 3, characterized in that, include: Step 1: Melt carbon steel, ferromanganese, ferrochrome, and ferrosilicon alloy raw materials in a medium-frequency induction furnace to form molten steel; Step 2: After the furnace charge is completely melted, deoxidation is performed, and ferroboron and rare earth alloys are added to adjust the content of each element. The percentage content by mass is as follows: C: 0.6%-1.2%, Mn: 13%-20%, Si: 0.4%-0.8%, S: 0.0035%-0.005%, P: 0.034%-0.037%, Cr: 3.0%-10%, B: 0.005%-0.02%, Re: 0.02%-0.03%, with the balance being Fe and unavoidable impurities. Step 3: Pour molten steel into a ladle, purify the ladle with argon, let it stand, and then pour the casting at a temperature of 1400℃-1450℃ to obtain the casting. Step 4: Perform solution treatment on the casting at a temperature of 1020℃-1120℃, hold at the temperature and immediately quench in water to room temperature; then perform low-temperature tempering at a temperature of 200℃-250℃, hold at the temperature for 4-8 hours and then air cool to room temperature.

5. The method for preparing wear-resistant high-manganese steel according to claim 4, characterized in that, In step 2, the deoxidation operation is carried out by inserting aluminum wires for deep deoxidation when the furnace temperature reaches 1580℃-1600℃. The addition of ferroborone and rare earth alloys should be done 8-10 minutes before tapping.

6. The method for preparing wear-resistant high-manganese steel according to claim 4, characterized in that, In step 3, the argon blowing purification time is 2-4 minutes; in step 4, the heat preservation time of the solution treatment is determined according to the effective thickness of the casting, and 1 hour is maintained for every 25mm thickness.

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