An austenitic light-weight wear-resistant steel, a preparation method and application thereof

Abstract

The application provides an austenitic light-weight wear-resistant steel and a preparation method and application thereof, and belongs to the technical field of light-weight wear-resistant steel.The austenitic light-weight wear-resistant steel provided by the application contains, in percentage by mass, Mn 24-27%, Al 6.50-8.10%, C 0.85-1.12%, Si 0.10-0.30%, Cr 0.70-1.40%, Mo 0.40-0.80%, Ni 0.40-0.65%, Ce 0.04-0.07%, P≤0.03%, S≤0.01%, and the balance of Fe.The results of examples show that the austenitic light-weight wear-resistant steel provided by the application has a density <6.99g / cm 3 , a yield strength ≥588MPa, a tensile strength ≥910MPa, an elongation ≥52.6%, and a-40℃KV2 impact energy ≥95J, and the high-impact-energy wear resistance is improved by more than 30%.

Description

Technical Field

[0001] This invention relates to the field of lightweight wear-resistant steel technology, and in particular to an austenitic lightweight wear-resistant steel, its preparation method, and its application. Background Technology

[0002] With the development of industries such as metallurgy and mining, traditional high-manganese steel (ZGMn13) products are heavy, lack wear resistance, and are costly, making it difficult to meet the current demands of industrial and mining enterprises for low energy consumption and lightweight development. As research on improving the performance of traditional high-manganese steel continues, research on high-manganese steel with added Al is increasing. By adding the lightweight element Al to the steel to reduce its density, and then adding elements such as Mn and C to stabilize austenite, Fe-Mn-Al-C austenitic lightweight steel can be obtained. Fe-Mn-Al-C austenitic lightweight steel can improve the yield strength of the material at low temperatures and also gives the material good impact toughness. At the same time, the increase in Al content also reduces the density of the material. Under low impact energy, the work hardening produced gives Fe-Mn-Al-C lightweight steel better wear resistance.

[0003] However, there are still few examples of Fe-Mn-Al-C austenitic lightweight steel being used in the field of wear resistance. Most of the existing lightweight wear-resistant steels are high-manganese steels used in ball mill liners or crusher hammers. They require complex processes such as explosive hardening and shot peening to improve the hardness, strength and wear resistance of lightweight steel. At the same time, the complex production process increases manufacturing costs. In addition, there are problems such as insufficient addition of lightweight elements and excessive density.

[0004] Therefore, providing a low-density, high-strength, high-ductility, high-wear-resistance, and low-cost austenitic lightweight wear-resistant steel has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide an austenitic lightweight wear-resistant steel, its preparation method, and its applications. The austenitic lightweight wear-resistant steel provided by this invention has low density, high strength, high plasticity and toughness, high wear resistance, and low cost.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides an austenitic lightweight wear-resistant steel, comprising, by mass percentage: Mn 24-27%, Al 6.50-8.10%, C 0.85-1.12%, Si 0.10-0.30%, Cr 0.70-1.40%, Mo 0.40-0.80%, Ni 0.40-0.65%, Ce 0.04-0.07%, P ≤0.03%, S ≤0.01%, and the balance Fe.

[0008] Preferably, in the austenitic lightweight wear-resistant steel, the mass content of each element is 0.64≤(0.1Mn+3C) / Al≤0.89.

[0009] This invention provides a method for preparing the austenitic lightweight wear-resistant steel described in the above technical solution, comprising the following steps:

[0010] (a) The alloy raw materials are melted and then cast to obtain a billet;

[0011] (b) The billet obtained in step (a) is subjected to solution treatment to obtain a solution-treated ingot billet;

[0012] (c) The solution-treated billet obtained in step (b) is subjected to aging treatment to obtain austenitic lightweight wear-resistant steel.

[0013] Preferably, the casting temperature in step (a) is 1400–1430°C, and the casting time is ≤10 min.

[0014] Preferably, the solution treatment temperature in step (b) is 1090–1110°C, and the solution treatment holding time is 1–2 hours.

[0015] Preferably, the heating method for the solution treatment in step (b) is segmented heating;

[0016] The segmented heating includes a first heating, a first holding, a second heating, a second holding, and a third heating performed sequentially.

[0017] The heating rate for the first heating is 55–60 °C / h;

[0018] The second heating rate is 40–45 °C / h;

[0019] The heating rate for the third heating step is 35–40 °C / h.

[0020] Preferably, the temperature of the first heat preservation is 480-500℃, and the time of the first heat preservation is 0.5-1.5h;

[0021] The second insulation temperature is 650-670℃, and the second insulation time is 0.5-1.5h.

[0022] Preferably, the cooling method for the solution treatment in step (b) is water cooling.

[0023] Preferably, in step (c), the aging treatment temperature is 480–520°C, the aging treatment time is 4–6°C / h, and the heating rate to the aging treatment temperature is 40–45°C / h.

[0024] This invention provides the application of the austenitic lightweight wear-resistant steel described in the above technical solution or the austenitic lightweight wear-resistant steel prepared by the preparation method described in the above technical solution in excavator track plates.

[0025] This invention provides an austenitic lightweight wear-resistant steel, comprising, by mass percentage: Mn 24-27%, Al 6.50-8.10%, C 0.85-1.12%, Si 0.10-0.30%, Cr 0.70-1.40%, Mo 0.40-0.80%, Ni 0.40-0.65%, Ce 0.04-0.07%, P ≤0.03%, S ≤0.01%, and the balance Fe. The austenitic lightweight wear-resistant steel provided by this invention regulates the precipitation behavior of κ carbides by adding Mo, Ni, Ce, Mn, and Cr elements. Mn and Cr elements suppress the κ brittle phase, improving the steel's ductility, toughness, and corrosion resistance. The addition of Cr can form chromium alloy cementite (Fe,Cr)3C, resulting in dispersed hard carbide particles distributed in the high-toughness austenitic matrix, thereby improving wear resistance. The combined addition of Cr and Mo can form small granular composite carbides dispersed in the austenitic matrix. These carbides are hard wear-resistant phases, improving the steel's wear resistance. By controlling the content of lightweight elements Al, C, Si, and Mn, as well as Cr, the density of the steel is effectively reduced, the morphology of the carbides is changed, and the steel is guaranteed to have high strength, ductility, toughness, high wear resistance, and good comprehensive mechanical properties. By adjusting the composition and content of the lightweight wear-resistant steel, the hardness and high wear resistance can be achieved without using complex surface hardening processes such as explosive hardening and shot peening, reducing the cost of lightweight wear-resistant steel. The results of the examples show that the density ρ of the austenitic lightweight wear-resistant steel provided by the present invention is < 6.99 g / cm³. 3 Yield strength R eL ≥588MPa, tensile strength R m It has an impact strength of ≥910MPa, an elongation of A5≥52.6%, and an impact energy of -40℃KV2≥95J. The high impact energy improves wear resistance by more than 30%. It features low density, high strength, high plasticity and toughness, high wear resistance, and low cost. Attached Figure Description

[0026] Figure 1 This is a side microstructure diagram of the high impact energy (4J) of the austenitic lightweight wear-resistant steel in Example 1 of the present invention;

[0027] Figure 2 This is a SEM image of the high impact energy (4J) wear surface of the austenitic lightweight wear-resistant steel in Example 1 of the present invention.

[0028] Figure 3 This is a SEM image of the high-impact energy (4J) wear surface of the high-manganese steel in Comparative Example 1 of the present invention. Detailed Implementation

[0029] This invention provides an austenitic lightweight wear-resistant steel, comprising, by mass percentage: Mn 24-27%, Al 6.50-8.10%, C 0.85-1.12%, Si 0.10-0.30%, Cr 0.70-1.40%, Mo 0.40-0.80%, Ni 0.40-0.65%, Ce 0.04-0.07%, P ≤0.03%, S ≤0.01%, and the balance Fe.

[0030] The austenitic lightweight wear-resistant steel provided by this invention, by mass percentage, comprises 24-27% Mn, preferably 24.5-26.5%, and more preferably 25-26%. In this invention, Mn is an austenite stabilizing element, capable of expanding the austenite phase region, shrinking the ferrite phase region, suppressing the brittle κ phase, and also playing a role in solid solution strengthening, thereby increasing the work hardening rate of the steel. A higher Mn content is beneficial for obtaining a single-phase austenitic structure, which helps improve the steel's plasticity, toughness, and corrosion resistance. However, with increasing Mn content, the grains in the steel coarsen, the thermal conductivity decreases sharply, and the coefficient of linear expansion increases, which can lead to the formation of large internal stresses during heating or cooling, significantly increasing the tendency to crack and deteriorating hot workability. Limiting the Mn content to the above-mentioned range in this invention ensures that the steel possesses good plasticity, toughness, and corrosion resistance.

[0031] The austenitic lightweight wear-resistant steel provided by this invention comprises 6.50–8.10% Al by weight, preferably 6.80–7.80%, and more preferably 7.0–7.5%. In this invention, Al can significantly reduce the density of the steel while significantly improving its corrosion resistance and strength. However, Al is a ferrite-forming element; excessively high Al content will narrow the austenite range and promote the brittle δ and κ phases, thus reducing ductility, toughness, and corrosion resistance. Limiting the Al content to the above-mentioned range ensures that the steel possesses good ductility, toughness, and corrosion resistance.

[0032] The austenitic lightweight wear-resistant steel provided by this invention, by mass percentage, comprises 0.85–1.12% C, preferably 0.9–1.00%, and more preferably 0.93–0.97%. In this invention, C is an austenite stabilizing and solid solution strengthening element. Increasing the C content can expand the austenite phase region and improve strength. However, excessive C will form intergranular brittle phases with Mn and Al, which is detrimental to the steel's corrosion resistance and ductility. Limiting the C content to the above-mentioned range ensures that the steel has sufficient wear resistance and a stable austenitic structure.

[0033] The austenitic lightweight wear-resistant steel provided by this invention, by weight percentage, comprises 0.10–0.30% Si, preferably 0.10–0.20%, and more preferably 0.15–0.20%. In this invention, Si is an effective deoxidizing and solid solution strengthening element; increasing the Si content can improve strength and hardness. However, excessive Si reduces the solubility of carbon in austenite, increasing the number of δ-phase and κ carbides, and correspondingly decreasing impact toughness and corrosion resistance. Limiting the Si content to the above-mentioned range ensures the steel's strength, hardness, impact toughness, and corrosion resistance.

[0034] The austenitic lightweight wear-resistant steel provided by this invention, by mass percentage, comprises 0.70–1.40% Cr, preferably 0.80–1.20%, and more preferably 0.90–1.00%. In this invention, most of the Cr can dissolve into austenite, improving its stability and suppressing intergranular κ carbides during cooling. Increasing the Cr content can simultaneously improve corrosion resistance and ductility. When Cr is added to high-manganese steel, it forms chromium alloy cementite (Fe,Cr)3C, which is more stable than cementite Fe3C. This alloy cementite is distributed in the steel, resulting in dispersed carbide hard points within the high-toughness austenitic matrix, thereby improving wear resistance. However, excessive Cr can easily increase the precipitation of intergranular network carbides, which conversely reduces impact toughness and ductility. Limiting the Cr content to the above-mentioned range in this invention ensures the corrosion resistance and ductility of the steel.

[0035] The austenitic lightweight wear-resistant steel provided by this invention, by mass percentage, comprises 0.40–0.80% Mo, preferably 0.40–0.60%, and more preferably 0.40–0.50%. In this invention, Mo dissolved in austenite causes strong lattice distortion, increases the resistance to dislocation movement, and plays a role in solid solution strengthening, thereby increasing the hardness of the matrix. Mo forms high-melting-point stable carbon compounds with C in the steel and is dispersed in the austenitic matrix, enhancing the hardness of the matrix and playing a role in precipitation strengthening, thus improving the wear resistance of the steel. However, Mo delays the kinetic process of κ carbide precipitation during aging, and Mo replacing Fe in κ carbides is energy-disadvantageous. Limiting the Mo content to the above-mentioned range in this invention ensures the hardness and wear resistance of the steel.

[0036] The austenitic lightweight wear-resistant steel provided by this invention, by weight percentage, comprises 0.40–0.65% Ni, preferably 0.40–0.55%, and more preferably 0.40–0.45%. In this invention, Ni can inhibit the desolvation of carbon from austenite and suppress the precipitation of intergranular carbides. Simultaneously, Ni improves oxidation resistance, and increasing the Ni content can simultaneously improve corrosion resistance and low-temperature toughness. Limiting the Ni content to the above-mentioned range in this invention can improve the corrosion resistance and low-temperature toughness of the steel while reducing the cost of the alloy.

[0037] The austenitic lightweight wear-resistant steel provided by this invention, by mass percentage, comprises 0.04–0.07% Ce, preferably 0.04–0.06%, and more preferably 0.04–0.05%. In this invention, Ce can transform irregular sulfide and oxide inclusions in the steel into spherical or ellipsoidal, small-sized, and diffusely distributed rare earth inclusions, and can also reduce the amount of MnS inclusions in the steel. However, excessive addition will increase the size of the inclusions. Limiting the Ce content to the above-mentioned range in this invention can improve the strength and toughness of the steel.

[0038] The austenitic lightweight wear-resistant steel provided by this invention, by weight percentage, comprises P ≤ 0.03%, preferably P ≤ 0.02%. In this invention, P is a harmful element introduced during the steelmaking process. High carbon content in steel reduces the solubility of P in austenite, easily leading to intergranular precipitation, increasing the likelihood of hot cracking in the workpiece, and reducing the steel's ductility and toughness. Limiting the P content to the above-mentioned range in this invention improves the steel's ductility and toughness.

[0039] The austenitic lightweight wear-resistant steel provided by this invention, by weight percentage, comprises S ≤ 0.01%, preferably ≤ 0.005%. In this invention, S readily forms MnS inclusions, increasing hot brittleness and reducing ductility and toughness. Limiting the S content to the above-mentioned range in this invention can improve the ductility and toughness of the steel.

[0040] In this invention, the mass content of Mn, C, and Al is preferably 0.64 ≤ (0.1Mn + 3C) / Al ≤ 0.89, more preferably 0.64 ≤ (0.1Mn + 3C) / Al ≤ 0.80, based on the mass content of each element. In this invention, a stable single-phase austenite temperature range of 1090–1100℃ can be obtained through the compositional control formula between Mn, Al, and C, thereby obtaining a room-temperature fully austenitic structure through quenching at high temperatures. The austenitic structure undergoes work hardening after being subjected to impact loads. The fully austenitic structure can improve the work hardening rate, significantly enhancing the wear resistance of the material under high impact energy.

[0041] The austenitic lightweight wear-resistant steel provided by this invention regulates the precipitation behavior of κ carbides by adding Mo, Ni, Ce, Mn, and Cr elements. Mn and Cr elements suppress the κ brittle phase, improving the steel's ductility, toughness, and corrosion resistance. The addition of Cr can form chromium alloy cementite (Fe,Cr)3C, resulting in dispersed hard carbide particles distributed in the high-toughness austenitic matrix, thereby improving wear resistance. The combined addition of Cr and Mo can form small granular composite carbides dispersed in the austenitic matrix. These carbides are hard wear-resistant phases, improving the steel's wear resistance. By controlling the content of lightweight elements Al, C, Si, and Mn, as well as Cr, the density of the steel is effectively reduced, the morphology of the carbides is changed, and the steel is guaranteed to have high strength, ductility, toughness, high wear resistance, and good comprehensive mechanical properties. By adjusting the composition and content of the lightweight wear-resistant steel, the hardness and high wear resistance can be achieved without using complex surface hardening processes such as explosive hardening and shot peening, reducing the cost of lightweight wear-resistant steel.

[0042] This invention also provides a method for preparing the austenitic lightweight wear-resistant steel described in the above technical solution, comprising the following steps:

[0043] (a) The alloy raw materials are melted and then cast to obtain a billet;

[0044] (b) The billet obtained in step (a) is subjected to solution treatment to obtain a solution-treated ingot billet;

[0045] (c) The solution-treated billet obtained in step (b) is subjected to aging treatment to obtain austenitic lightweight wear-resistant steel.

[0046] This invention involves melting alloy raw materials and then casting them to obtain a cast billet.

[0047] In this invention, the preferred alloy raw materials are high-carbon ferromanganese with a ferromanganese content of 65%, metallic manganese with a purity of 99%, metallic aluminum with a purity of 99.95%, a carbon raiser with a carbon content of 98.5% to 99.0%, a ferromolybdenum alloy with a ferromolybdenum content of 63%, a micro-carbon ferrochrome alloy with a ferrochrome content of 95%, nickel wire with a purity of 99.95%, cerium powder with a purity of 99.99%, and industrial pure iron with a purity of 99.99%. Limiting the types and purities of the alloy raw materials to the above-mentioned ranges in this invention can reduce impurities in the alloy.

[0048] In this invention, the melting is preferably vacuum induction melting.

[0049] In this invention, the preferred order of adding the alloy raw materials during smelting is as follows: first, industrial pure iron, high-carbon ferromanganese, ferromolybdenum alloy, and low-carbon ferrochrome alloy are melted, then metallic manganese is added for further melting. After the metallic manganese has melted completely, a carbon raiser is added. After complete melting, nickel wire and cerium powder are added sequentially for further melting. Finally, after complete melting, metallic aluminum is added in batches. This invention limits the addition of raw materials to the above order to ensure a high smelting yield under high Al content conditions.

[0050] In this invention, the addition of aluminum in batches is preferably done in two batches; the amount of the first batch of aluminum added in the two batches is preferably 65-70% of the total mass of aluminum; and the amount of the second batch of aluminum added in the two batches is preferably 30-35% of the total mass of aluminum. This invention, by adding aluminum in batches during smelting, allows for maximum control over the Al content range.

[0051] In this invention, the casting temperature is preferably 1400–1430°C, more preferably 1410–1420°C; the casting time is preferably ≤10 min, more preferably 5–8 min. This invention obtains the desired billet through casting.

[0052] The present invention does not impose any special limitation on the casting method; any casting method commonly used by those skilled in the art can be used.

[0053] In this invention, the cooling method after casting is preferably air cooling; the air cooling rate is preferably 1-4°C / s. By limiting the cooling method and cooling rate to the above range, this invention can avoid excessively rapid cooling that could cause precipitation of the microstructure, resulting in stress concentration and matrix cracking.

[0054] After obtaining the cast billet, the present invention performs a solution treatment on the cast billet to obtain a solution-treated ingot billet.

[0055] In this invention, the riser of the ingot is preferably removed before solution treatment. There are no special limitations on the riser removal operation; it can be performed using conventional methods employed by those skilled in the art.

[0056] In this invention, the solution treatment temperature is preferably 1090-1110℃, more preferably 1095-1105℃; the solution treatment holding time is preferably 1-2h, more preferably 1.5-2h.

[0057] In this invention, the solution treatment is preferably performed using a segmented heating method. The segmented heating preferably includes a first heating, a first holding, a second heating, a second holding, and a third heating performed sequentially. The heating rate of the first heating is preferably 55–60 °C / h, more preferably 58 °C / h; the heating rate of the second heating is preferably 40–45 °C / h, more preferably 43 °C / h; and the heating rate of the third heating is preferably 35–40 °C / h, more preferably 38 °C / h. This invention reduces the heating rate by approximately 10 °C as the temperature increases during segmented heating, thereby minimizing cracking and segregation that may result from uneven internal and external temperatures during the ingot heating process.

[0058] In this invention, the temperature of the first heat preservation is preferably 480–500℃, more preferably 485–490℃; the time of the first heat preservation is preferably 0.5–1.5 h, more preferably 1 h; the temperature of the second heat preservation is preferably 650–670℃, more preferably 655–665℃; and the time of the second heat preservation is preferably 0.5–1.5 h, more preferably 1 h. By setting the temperature and heat preservation time of each stage of the solution treatment within the above ranges, this invention can improve the effect of solution strengthening and enhance the performance of the steel.

[0059] In this invention, the cooling method for the solution treatment is preferably water cooling; the cooling rate of the water cooling is preferably 15-20°C / s; and the water cooling time is preferably 1-2 minutes. By using water cooling and setting the cooling rate and time within the above ranges, this invention can obtain a uniform austenitic structure, thereby improving the strength and toughness of the steel.

[0060] After obtaining the solution-treated ingot, the present invention performs an aging treatment on the solution-treated ingot to obtain austenitic lightweight wear-resistant steel.

[0061] In this invention, the aging treatment temperature is preferably 480–520°C, more preferably 490–510°C; the aging treatment time is preferably 4–6 hours, more preferably 5 hours; and the heating rate to the aging treatment temperature is preferably 40–45°C / hour. Setting the aging treatment time, temperature, and heating rate within the above ranges allows for better aging effects, thereby improving the steel's properties.

[0062] In this invention, the cooling method for the aging treatment is preferably air cooling; the air cooling rate is preferably 1–4 °C / s; and the air cooling time is preferably 6–8 min. This invention improves the strength and toughness of steel by using air cooling and setting the air cooling rate and time within the above ranges.

[0063] This invention can effectively improve the initial hardness of the matrix and enhance the strength, toughness, and wear resistance of Nb, V, and Ti alloyed lightweight wear-resistant steel through solution treatment and aging treatment.

[0064] The present invention also provides the application of the austenitic lightweight wear-resistant steel described in the above technical solution or the austenitic lightweight wear-resistant steel prepared by the preparation method described in the above technical solution in excavator track plates.

[0065] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0066] Example 1

[0067] An austenitic lightweight wear-resistant steel, by mass percentage, comprises: Mn 27%, Al 8.10%, C 0.85%, Si 0.10%, Cr 0.70%, Mo 0.40%, Ni 0.40%, Ce 0.04%, P 0.028%, S 0.009%, and the balance Fe; wherein, (0.1Mn+3C) / Al=0.648;

[0068] The preparation method of the austenitic lightweight wear-resistant steel consists of the following steps:

[0069] (a) Smelting is carried out in a vacuum induction furnace. According to the chemical composition of the steel, before smelting, industrial pure iron with a purity of 99.99%, high-carbon ferromanganese with a ferromanganese content of 65%, ferromolybdenum alloy with a ferromolybdenum content of 63%, and micro-carbon ferrochrome alloy with a ferrochrome content of 95% are added to the furnace. The furnace is then heated by electricity. After the raw materials are completely melted, metallic manganese with a purity of 99% is added. After the metallic manganese is completely melted, a carburizing agent is added. After the mixture is heated and melted, a carburizing agent with a purity of 99.95% is added sequentially. Nickel wire and cerium powder with a purity of 99.99% were added. After the metal was completely melted, 70% of the total mass of aluminum metal with a purity of 99.95% was added. Half an hour before the metal was tapped, 30% of the total mass of aluminum metal with a purity of 99.95% was added. After all the raw materials were melted, the temperature of the molten steel was controlled at 1430℃ and cast into a billet. The casting time was 8 minutes. After the billet solidified, it was demolded and air-cooled to room temperature at a cooling rate of 2℃ / s.

[0070] (b) After removing the riser from the billet obtained in step (a), heat it to 485°C at a heating rate of 58°C / h and hold it for 1 hour. Then heat it to 660°C at a heating rate of 43°C / h and hold it for 1 hour. Then heat it to 1100°C at a heating rate of 38°C / h and hold it for 2 hours. After the billet is completely homogeneous, it is taken out of the furnace and sent to a water tank for water cooling. The cooling rate of the water cooling is 18°C / s and the water cooling time is 1 minute to obtain a solution-treated ingot.

[0071] (c) The solution-treated billet obtained in step (b) is heated to 500°C at a heating rate of 43°C / h and held for 5 hours, and then air-cooled to room temperature at a cooling rate of 4°C / s for 8 minutes to obtain austenitic lightweight wear-resistant steel.

[0072] The performance data of the austenitic lightweight wear-resistant steel in Example 1 are shown in Table 1. The high impact energy (4J) wear resistance is 10.81g. -1 This represents a 39% increase compared to control 1.

[0073] Example 2

[0074] An austenitic lightweight wear-resistant steel, by mass percentage, comprises: Mn 26%, Al 7.50%, C 0.93%, Si 0.20%, Cr 1.0%, Mo 0.6%, Ni 0.45%, Ce 0.04%, P 0.029%, S 0.01%, and the balance Fe; wherein, (0.1Mn+3C) / Al=0.719;

[0075] The preparation method of the austenitic lightweight wear-resistant steel consists of the following steps:

[0076] (a) Smelting is carried out in a vacuum induction melting furnace. According to the chemical composition of the steel, before smelting, industrial pure iron with a purity of 99.99%, high-carbon ferromanganese with a ferromanganese content of 65%, ferromolybdenum alloy with a ferromolybdenum content of 63%, and micro-carbon ferrochrome alloy with a ferrochrome content of 95% are added to the furnace. The furnace is then heated by electricity. After the raw materials are completely melted, metallic manganese with a purity of 99% is added. After the metallic manganese is completely melted, a carbon raiser is added. After the mixture is heated and melted, nickel wire with a purity of 99.95% and cerium powder with a purity of 99.99% are added sequentially. After the steel is completely melted, add 70% of the total mass of aluminum metal with a purity of 99.95%. Half an hour before the steel is tapped, add another 30% of the total mass of aluminum metal with a purity of 99.95%. After all the raw materials have melted, cast the steel into a billet at a temperature of 1430℃ for 7 minutes. After the billet solidifies, demold it and air cool it to room temperature at a cooling rate of 3℃ / s.

[0077] (b) After removing the riser from the billet obtained in step (a), heat it to 485°C at a heating rate of 58°C / h and hold it for 1 hour. Then heat it to 660°C at a heating rate of 43°C / h and hold it for 1 hour. Then heat it to 1100°C at a heating rate of 38°C / h and hold it for 2 hours. After the billet is completely homogeneous, it is taken out of the furnace and sent to a water tank for water cooling. The cooling rate of the water cooling is 18°C / s and the water cooling time is 1 minute to obtain a solution-treated ingot.

[0078] (c) The solution-treated billet obtained in step (b) is heated to 500°C at a heating rate of 43°C / h and held for 5 hours, and then air-cooled to room temperature at a cooling rate of 4°C / s for 7 minutes to obtain austenitic lightweight wear-resistant steel.

[0079] The performance data of the austenitic lightweight wear-resistant steel in Example 2 are shown in Table 1. The high impact energy (4J) wear resistance is 10.49g. -1 This represents a 35% increase compared to control 1.

[0080] Example 3

[0081] An austenitic lightweight wear-resistant steel, by mass percentage, comprises: Mn 25%, Al 6.9%, C 1.01%, Si 0.20%, Cr 1.2%, Mo 0.6%, Ni 0.55%, Ce 0.04%, P 0.028%, S 0.01%, and the balance Fe; wherein, (0.1Mn+3C) / Al=0.801;

[0082] The preparation method of the austenitic lightweight wear-resistant steel consists of the following steps:

[0083] (a) Smelting is carried out in a vacuum induction furnace. According to the chemical composition of the steel, before smelting, industrial pure iron with a purity of 99.99%, high-carbon ferromanganese with a ferromanganese content of 65%, ferromolybdenum alloy with a ferromolybdenum content of 63%, and micro-carbon ferrochrome alloy with a ferrochrome content of 95% are added to the furnace. The furnace is then heated by electricity. After the raw materials are completely melted, metallic manganese with a purity of 99% is added. After the metallic manganese is completely melted, a carburizing agent is added. After the mixture is heated and melted, a carburizing agent with a purity of 99.95% is added sequentially. Nickel wire and cerium powder with a purity of 99.99% were added. After the metal was completely melted, 70% of the total mass of aluminum metal with a purity of 99.95% was added. Half an hour before the metal was tapped, 30% of the total mass of aluminum metal with a purity of 99.95% was added. After all the raw materials were melted, the temperature of the molten steel was controlled at 1420℃ and cast into a billet. The casting time was 7 minutes. After the billet solidified, it was demolded and air-cooled to room temperature at a cooling rate of 4℃ / s.

[0084] (b) After removing the riser from the billet obtained in step (a), heat it to 485°C at a heating rate of 58°C / h and hold it for 1 hour. Then heat it to 660°C at a heating rate of 43°C / h and hold it for 1 hour. Then heat it to 1100°C at a heating rate of 38°C / h and hold it for 2 hours. After the billet is completely homogeneous, it is taken out of the furnace and sent to a water tank for water cooling. The cooling rate of the water cooling is 18°C / s and the water cooling time is 1 minute to obtain a solution-treated ingot.

[0085] (c) The solution-treated billet obtained in step (b) is heated to 500°C at a heating rate of 43°C / h and held for 5 hours, and then air-cooled to room temperature at a cooling rate of 4°C / s for 7 minutes to obtain austenitic lightweight wear-resistant steel.

[0086] The performance data of the austenitic lightweight wear-resistant steel in Example 3 are shown in Table 1. The high impact energy (4J) wear resistance is 10.13g. -1 This represents a 30% increase compared to control 1.

[0087] Example 4

[0088] An austenitic lightweight wear-resistant steel, by mass percentage, comprises: Mn 24%, Al 6.5%, C 1.12%, Si 0.30%, Cr 1.40%, Mo 0.80%, Ni 0.65%, Ce 0.07%, P 0.025%, S 0.009%, and the balance Fe; wherein, (0.1Mn+3C) / Al=0.886;

[0089] The preparation method of the austenitic lightweight wear-resistant steel consists of the following steps:

[0090] (a) Smelting is carried out in a vacuum induction furnace. According to the chemical composition of the steel, before smelting, industrial pure iron with a purity of 99.99%, high-carbon ferromanganese with a ferromanganese content of 65%, ferromolybdenum alloy with a ferromolybdenum content of 63%, and micro-carbon ferrochrome alloy with a ferrochrome content of 95% are added to the furnace. The furnace is then heated by electricity. After the raw materials are completely melted, metallic manganese with a purity of 99% is added. After the metallic manganese is completely melted, a carburizing agent is added. After the mixture is heated and melted, a carburizing agent with a purity of 99.95% is added sequentially. Nickel wire and cerium powder with a purity of 99.99% were added. After the metal was completely melted, 70% of the total mass of aluminum metal with a purity of 99.95% was added. Half an hour before the metal was tapped, 30% of the total mass of aluminum metal with a purity of 99.95% was added. After all the raw materials were melted, the temperature of the molten steel was controlled at 1420℃ and cast into a billet. The casting time was 7 minutes. After the billet solidified, it was demolded and air-cooled to room temperature at a cooling rate of 4℃ / s.

[0091] (b) After removing the riser from the billet obtained in step (a), heat it to 485°C at a heating rate of 58°C / h and hold it for 1 hour. Then heat it to 660°C at a heating rate of 43°C / h and hold it for 1 hour. Then heat it to 1100°C at a heating rate of 38°C / h and hold it for 2 hours. After the billet is completely homogeneous, it is taken out of the furnace and sent to a water tank for water cooling. The cooling rate of the water cooling is 18°C / s and the water cooling time is 1 minute to obtain a solution-treated ingot.

[0092] (c) The solution-treated billet obtained in step (b) is heated to 500°C at a heating rate of 43°C / h and held for 5 hours, and then air-cooled to room temperature at a cooling rate of 4°C / s for 6 minutes to obtain austenitic lightweight wear-resistant steel.

[0093] The performance data of the austenitic lightweight wear-resistant steel in Example 4 are shown in Table 1. The high impact energy (4J) wear resistance is 10.26g. -1 This represents a 32% increase compared to control 1.

[0094] Comparative Example 1

[0095] A high-manganese steel, by mass percentage, has the following composition: Mn 13.3%, C 1.1%, Si 0.35%, Cr 0.5%, Mo 1.0%, P 0.03%, S 0.01%, and the balance Fe;

[0096] The method for preparing the high-manganese steel comprises the following steps:

[0097] (a) The steel is smelted in a vacuum induction furnace. According to the chemical composition of the steel, before smelting, 99.99% pure industrial iron and 65% high carbon ferromanganese are added. The temperature is raised by electricity. After the raw materials are melted, 99% pure metallic manganese is added. After the metallic manganese is melted, 63% molybdenum ferroalloy and 95% micro carbon ferrochrome ferroalloy are added. After all the raw materials are melted, the temperature of the molten steel is controlled at 1440°C and cast into a billet. The casting time is 8 minutes. After the casting is completed and the billet solidifies, it is demolded and air-cooled to room temperature at a cooling rate of 4°C / s.

[0098] (b) After removing the riser from the billet obtained in step (a), heat it to 480°C at a heating rate of 45°C / h and hold it for 1 hour. Then heat it to 650°C at a heating rate of 25°C / h and hold it for 2 hours. Then heat it to 1080°C at a heating rate of 40°C / h and hold it for 2 hours. After the billet is completely homogeneous, it is taken out of the furnace and sent to a water tank for water cooling. First, it is cooled to 650°C at a cooling rate of 10°C / s, and then cooled to room temperature at a cooling rate of 15°C / s to obtain a solution-treated ingot.

[0099] (c) The solution-treated billet obtained in step (b) is heated to 350°C at a heating rate of 40°C / h and held for 4 hours, then air-cooled to room temperature at a cooling rate of 3°C / s for 2 minutes to obtain high-manganese steel.

[0100] The performance data of the high-manganese steel in Comparative Example 1 are shown in Table 1. The high impact energy (4J) and wear resistance are 7.77g. -1 .

[0101] The wear-resistant steels prepared in Examples 1-4 and Comparative Example 1 were tested for tensile strength, yield strength, elongation, impact performance, and wear resistance. The specific testing methods are as follows: Tensile strength, yield strength, and elongation were tested according to national standards GB / T 1231-2006 and GB / T 228.1-2010 "Metallic Materials - Tensile Testing - Part 1: Room Temperature Test Method". Round bar tensile specimens were taken from one-quarter of the ingot's length from the core, and a tensile test was conducted at room temperature on a tensile testing machine at a tensile rate of 3 mm / min. Impact performance was tested according to GB / T 229-2007 "Metallic Materials - Charpy Pendulum Impact Test Method". Standard impact specimens were taken from one-quarter of the ingot's length from the core, and an impact test was conducted at -40℃. Wear resistance was tested using an MLD-10 impact wear testing machine at room temperature with an impact load of 4 J and a flow rate of 20 kg / h.

[0102] The properties of the austenitic lightweight wear-resistant steels prepared in Examples 1-4 and Comparative Example 1 are shown in Table 1:

[0103] Table 1. Properties of the austenitic lightweight wear-resistant steels prepared in Examples 1-4 and Comparative Example 1

[0104]

[0105] The high impact energy (4J) side microstructure of the austenitic lightweight wear-resistant steel in Example 1 of this invention is shown in the figure below. Figure 1 As shown; SEM image of the high impact energy (4J) wear surface of the austenitic lightweight wear-resistant steel in Example 1 is shown. Figure 2 As shown; SEM image of the high impact energy (4J) wear surface of high manganese steel in Comparative Example 1 is shown. Figure 3 As shown.

[0106] from Figures 1-3 It can be seen that the surface morphologies after wear under different impact energies after heat treatment are similar. Taking Example 1 as an example, the wear mechanism of high impact energy under aging conditions is plastic deformation + fatigue spalling, and the surface morphology is mostly plastic deformation (e.g. Figure 2 The wear mechanism of Comparative Example 1 under high impact energy is fatigue spalling + crack propagation (e.g., Figure 3Microcracks extend to the surface, making the surface more prone to peeling after impact and wear. It has poor ability to withstand plastic deformation, and its ability to withstand impact and wear is poor after the surface hardened layer peels off. Its wear resistance is far lower than that of the embodiments of the present invention.

[0107] The austenitic lightweight wear-resistant steel prepared by this invention has a density ρ ≤ 6.99 g / cm³. 3 The matrix structure is austenite + carbides (such as...) Figure 1 Yield strength R eL With a tensile strength of 588–678 MPa and a tensile strength R m The surface hardness is 910–1006 MPa, the elongation (A5) is 52.6–60.3%, and the KV2 at -40℃ is 95–156 J. Impact wear leads to work hardening, increasing surface hardness and exhibiting significant dislocation line aggregation. Wear resistance is more than 30% higher than that of Comparative Example 1. It features low density, high strength, high plasticity and toughness, and high wear resistance, and is low-cost, simple to produce, and suitable for large-scale production.

[0108] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An austenitic lightweight wear-resistant steel, comprising, by mass percentage: Mn 24~27%, Al 6.50~8.10%, C 0.85~1.12%, Si 0.10~0.30%, Cr 0.70~1.40%, Mo 0.40~0.80%, Ni 0.40~0.65%, Ce 0.04~0.07%, P≤0.03%, S≤0.01%, and the balance Fe; In the aforementioned austenitic lightweight wear-resistant steel, based on the mass content of each element, 0.64≤(0.1Mn+3C) / Al≤0.80; The preparation method of the austenitic lightweight wear-resistant steel consists of the following steps: (a) The alloy raw materials are melted and then cast to obtain a billet; (b) The billet obtained in step (a) is subjected to solution treatment to obtain a solution-treated ingot billet; (c) The solution-treated billet obtained in step (b) is subjected to aging treatment to obtain austenitic lightweight wear-resistant steel; The solution treatment temperature in step (b) is 1090~1110℃, and the heat treatment time is 1~2h. The heating method for the solution treatment in step (b) is segmented heating; The segmented heating includes a first heating, a first holding, a second heating, a second holding, and a third heating performed sequentially. The heating rate of the first heating is 55~60℃ / h; The second heating rate is 40~45℃ / h; The heating rate for the third heating step is 35~40℃ / h; The temperature of the first insulation is 480~500℃, and the duration of the first insulation is 0.5~1.5h; The second insulation temperature is 650~670℃, and the second insulation time is 0.5~1.5h.

2. The method for preparing the austenitic lightweight wear-resistant steel according to claim 1 comprises the following steps: (a) The alloy raw materials are melted and then cast to obtain a billet; (b) The billet obtained in step (a) is subjected to solution treatment to obtain a solution-treated ingot billet; (c) The solution-treated billet obtained in step (b) is subjected to aging treatment to obtain austenitic lightweight wear-resistant steel; The solution treatment temperature in step (b) is 1090~1110℃, and the heat treatment time is 1~2h. The heating method for the solution treatment in step (b) is segmented heating; The segmented heating includes a first heating, a first holding, a second heating, a second holding, and a third heating performed sequentially. The heating rate of the first heating is 55~60℃ / h; The second heating rate is 40~45℃ / h; The heating rate for the third heating step is 35~40℃ / h; The temperature of the first insulation is 480~500℃, and the duration of the first insulation is 0.5~1.5h; The second insulation temperature is 650~670℃, and the second insulation time is 0.5~1.5h.

3. The preparation method according to claim 2, characterized in that, In step (a), the casting temperature is 1400~1430℃ and the casting time is ≤10min.

4. The preparation method according to claim 2, characterized in that, The cooling method for the solution treatment in step (b) is water cooling.

5. The preparation method according to claim 2, characterized in that, In step (c), the aging treatment temperature is 480~520℃, the aging treatment time is 4~6h, and the heating rate to the aging treatment temperature is 40~45℃ / h.

6. The application of the austenitic lightweight wear-resistant steel according to claim 1 or the austenitic lightweight wear-resistant steel prepared by the preparation method according to any one of claims 2 to 5 in excavator track plates.

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