Steel for high manganese steel cutter teeth and preparation method thereof

Abstract

The invention discloses steel for high-manganese steel cutter teeth and a preparation method of the steel, and belongs to the technical field of steel for dredging equipment. The technical problem that the service life of existing steel for reamer teeth is short due to poor wear resistance and low strength is solved. The steel for the high manganese steel cutter teeth comprises the following components in percentage by mass: 0.95 to 1.35 percent of C, 0.30 to 0.80 percent of Si, 11.0 to 14.0 percent of Mn, less than or equal to 0.070 percent of P, less than or equal to 0.030 percent of S, 0.20 to 0.30 percent of Mo, 0.020 to 0.030 percent of Cr, 0.01 to 0.2 percent of Nb and the balance of Fe and inevitable impurities. When the steel for the high-manganese steel cutter teeth is subjected to an impact load, the surface can generate an extremely strong work hardening effect, so that the surface wear resistance is greatly improved, and the core part still keeps high toughness.

Description

Technical Field

[0001] The invention relates to the technical field of dredging equipment, and in particular to a high manganese steel for cutter teeth and a preparation method thereof. Background Art

[0002] Large-scale offshore dredging equipment is crucial to marine construction and marine resource development, including two main types: cutter suction dredgers and trailing suction dredgers. Cutter suction dredgers use cutters to mix riverbed or seabed soil with cement into slurry, and then suck it up through the pump body. They are mainly used for dredging work in inland lakes and coastal ports. Trailing suction dredgers are more suitable for excavation and maintenance of narrow coastal access channels. However, no matter which type of dredger, the cutter teeth are in direct contact with various materials, and are frequently impacted and rubbed, which eventually leads to mechanical wear or broken teeth, seriously affecting the working life and efficiency of the dredger. Therefore, based on the needs of the actual service environment, it is necessary to develop a steel for cutter teeth with good wear resistance and high strength to improve the working efficiency of dredgers and the service life of cutter teeth, and promote the development of the domestic dredging industry.

[0003] At present, the domestic market mainly uses rake teeth and reamer teeth produced by internationally renowned dredging companies. The material composition and process are derived from abroad. The main material of reamer teeth on the domestic market is medium-carbon alloy steel. The hardness of this type of reamer teeth after heat treatment is usually around 48HRC, and the impact toughness is good. Although it can meet the use requirements of reamer teeth, the working time is not long and the wear is very serious. The general service life is less than 50 hours. The product performance is difficult to reach the level of imported teeth.

[0004] The materials of teeth and tooth seats widely used in the world are based on martensite, bainite, etc. Some of them contain boron alloy steel with boride as wear-resistant hard phase. The tooth tip and tooth seat are fine-tuned by alloy elements and heat treatment process to achieve the difference of mechanical properties, so as to be more suitable for the working conditions.

[0005] The existing tooth matrix is ​​still medium carbon alloy steel, and a wear-resistant coating is deposited on the tooth tip to enhance the wear resistance; however, its wear resistance and strength cannot meet the use requirements, and its service life is short. Summary of the invention

[0006] In view of the above analysis, the present invention aims to provide a high manganese steel for knife teeth and a preparation method thereof, so as to solve the technical problems that the existing high manganese steel for knife teeth has poor wear resistance and low strength resulting in a short service life.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions:

[0008] On the one hand, the present invention provides a high manganese steel for knife teeth, whose components, in mass percentage, include C: 0.95-1.35%, Si: 0.30-0.80%, Mn: 11.0-14.0%, P: ≤0.070%, S: ≤0.030%, Mo: 0.20-0.30%, Cr: 0.020-0.030%, Nb: 0.01-0.2%, and the balance is Fe and unavoidable impurities.

[0009] In one possible design, the components of high manganese steel for cutting teeth include, by mass percentage, C: 0.98-1.35%, Si: 0.31-0.80%, Mn: 11.0-14.0%, P: ≤0.040%, S: ≤0.020%, Mo: 0.25-0.30%, Cr: 0.23-0.30%, Nb: 0.04-0.2%, and the remainder is Fe and unavoidable impurities.

[0010] In one possible design, the components of high manganese steel for cutting teeth include, by mass percentage, C: 1.0-1.35%, Si: 0.44-0.80%, Mn: 12.0-14.0%, P: ≤0.010%, S: ≤0.010%, Mo: 0.27-0.30%, Cr: 0.25-0.30%, Nb: 0.1-0.2%, and the remainder is Fe and unavoidable impurities.

[0011] In one possible design, the components of high manganese steel for cutting teeth include, by mass percentage, C: 1.14-1.35%, Si: 0.50-0.80%, Mn: 13.3-14.0%, P: ≤0.006%, S: ≤0.009%, Mo: 0.28-0.30%, Cr: 0.27-0.30%, Nb: 0.15-0.2%, and the remainder is Fe and unavoidable impurities.

[0012] In one possible design, the composition of the high manganese steel for cutting teeth includes, by mass percentage, C: 0.95%, Si: 0.31%, Mn: 11.0%, P: 0.008%, S: 0.007%, Mo: 0.20%, Cr: 0.30%, Nb: 0.01%, and the remainder is Fe and unavoidable impurities.

[0013] In a possible design, the microstructure of the high manganese steel tooth steel is high manganese austenite and the second phase NbC.

[0014] On the other hand, the present invention also provides a method for preparing high manganese steel for blade teeth, which is used for the above-mentioned high manganese steel for blade teeth, and the preparation method comprises the following steps:

[0015] Step 1, smelting and pouring the obtained high manganese steel blade steel billet or ingot;

[0016] Use converter, electric furnace or induction furnace for smelting, and use continuous casting to produce billets or mold casting to produce ingots;

[0017] Step 2, subjecting the high manganese steel blade teeth steel billet or ingot to high temperature homogenization treatment and then forging, and then rolling;

[0018] Step 3: heat-treating the rolled billet or ingot, and cooling it to room temperature with water to obtain high manganese steel for blade teeth.

[0019] Furthermore, in step 2, the billet or ingot is first heated to 1000-1200° C. in a heating furnace, and kept at 1000-1200° C. for a certain period of time, and then forged after being taken out of the furnace, and air-cooled to room temperature after forging.

[0020] Furthermore, in step 2, the insulation time is 0.5 to 2 hours.

[0021] Furthermore, in step 3, the cast billet or ingot after the high temperature homogenization treatment is quenched;

[0022] The process includes heating the billet or ingot from room temperature to its complete austenitization temperature and keeping the temperature for a certain period of time, then cooling it to room temperature with water, and finally obtaining high manganese steel for knife teeth.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] (1) The present invention ensures the microstructure of the steel by precisely controlling the mass percentage of C, Si, Mn, Mo, Cr and Nb elements in the steel and combining the heat treatment process. When the high manganese steel is subjected to an impact load, a strong work hardening effect is produced on the surface, so that the surface wear resistance is greatly improved while the core still maintains high toughness, ensuring that the high manganese steel used for the cutter teeth has a good match between strength and toughness and excellent wear resistance, and ensuring that the steel of the present invention can meet the service conditions of the cutter teeth.

[0025] (2) The dredger blade steel prepared by the composition and method of the present invention has good comprehensive mechanical properties, wherein the yield strength is ≥400MPa, the tensile strength is ≥900MPa, the hardness is ≥20HRC, and the room temperature impact energy is ≥100J. As the impact load causes the surface to produce extremely strong work hardening, the yield strength is ≥1000MPa, the tensile strength is ≥1300MPa, and the hardness is ≥50HRC. The comprehensive mechanical properties far exceed the domestic blade steel level. This is because the high manganese steel blade steel produces extremely strong work hardening effect on the surface when subjected to impact load, which greatly improves the surface wear resistance while the core still maintains high toughness: that is, during the deformation process of the high manganese steel blade steel, the microstructure austenite undergoes TWIP effect due to deformation, and a large number of deformation twins and dislocations appear, which significantly improves the yield strength and tensile strength.

[0026] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0028] Figure 1 The microstructure diagram of the steel of Example 1 of the present invention;

[0029] Figure 2 The microstructure diagram of the steel of Example 2 of the present invention;

[0030] Figure 3 This is a microstructure diagram of the steel of Example 3 of the present invention;

[0031] Figure 4 This is a microstructure diagram of the steel of Example 4 of the present invention. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0033] The invention provides a high manganese steel for knife teeth, wherein the components thereof include, by mass percentage, C: 0.95-1.35%, Si: 0.30-0.80%, Mn: 11.0-14.0%, P: ≤0.070%, S: ≤0.030%, Mo: 0.20-0.30%, Cr: 0.20-0.30%, Nb: 0.01-0.2%, and the balance is Fe and inevitable impurities.

[0034] The following is a detailed description of the effects and dosage of the components in the present invention:

[0035] C: Carbon is a typical interstitial solid solution strengthening element. Increasing the carbon content in the alloy is an effective way to improve the strength of the alloy. However, too high a C content will reduce the plasticity, toughness and welding performance of the steel. Therefore, the C content is controlled between 0.95 and 1.35%.

[0036] Si: Si is a deoxidizer in steelmaking, but excessive silicon is detrimental to the steel's resistance to hydrogen sulfide corrosion. Therefore, the content of Si in the present invention is controlled to be 0.30-0.80%.

[0037] Mn: Mn can increase the austenite content and improve toughness. Therefore, the present invention controls the Mn content within the range of 11.0 to 14.0%.

[0038] P: P is an impurity in steel and is not conducive to toughness. In the present invention, the P content is controlled to be ≤0.070%.

[0039] S: S seriously deteriorates the corrosion resistance and toughness of steel. In the present invention, its content is controlled to be ≤ 0.030%.

[0040] Mo: The addition of Mo to steel can significantly improve the comprehensive properties of the steel, including improving strength, hardness, high temperature performance, hardenability and corrosion resistance, while also helping to maintain toughness and ductility. In the present invention, its content is controlled at 0.20-0.30%.

[0041] Cr: Cr is also an element that improves the hardenability of steel for cutter teeth. At the same time, Cr is also a corrosion-resistant element that can significantly improve corrosion resistance. The Cr content is controlled at 0.20-0.30%.

[0042] Nb: Nb can form high-hardness carbides with C. These carbides play a role of dispersion strengthening in steel, significantly improving the strength and hardness of steel. Through the fine grain strengthening mechanism, Nb can refine the grains of steel, thereby further improving the strength of steel. The Nb content is controlled between 0.01 and 0.2%.

[0043] In steel alloys, the above elements not only have their own unique functions, but also interact with each other in complex ways, jointly affecting the properties of the alloy.

[0044] The coordination effect of C and Nb: The interaction between C and Nb can form carbides with high hardness. These carbides play a role of dispersion strengthening in steel, significantly improving the strength and hardness of steel.

[0045] Combination of Mn and Cr: Both Mn and Cr can improve the hardenability of steel, while chromium can also improve the corrosion resistance of steel. The combined use of the two can further improve the comprehensive performance of steel.

[0046] Combination of Si and Mn: Si as a deoxidizer can improve the internal quality of steel, while Mn can improve the toughness of steel. The combination of the two helps to obtain steel that is both strong and tough.

[0047] Control of P and S: Strictly controlling the content of P and S is the key to preventing the deterioration of steel performance. Through the smelting process and refining process of the present invention, the content of these harmful elements can be reduced to a minimum.

[0048] It should be noted that the microstructure of the high manganese steel for cutter teeth of the present invention includes high manganese austenite. The high manganese austenite steel can produce a strong work hardening effect on the surface when the cutter teeth are subjected to impact loads, so that the wear resistance of the cutter teeth surface is greatly improved while the core still maintains high toughness.

[0049] In one embodiment of the present invention, the components of the high manganese steel for cutting teeth include, by mass percentage, C: 0.98-1.35%, Si: 0.31-0.80%, Mn: 11.0-14.0%, P: ≤0.040%, S: ≤0.020%, Mo: 0.25-0.030%, Cr: 0.23-0.30%, Nb: 0.04-0.2%, and the remainder is Fe and unavoidable impurities.

[0050] In one embodiment of the present invention, the components of the high manganese steel for cutting teeth include, by mass percentage, C: 1.0-1.35%, Si: 0.44-0.80%, Mn: 12.0-14.0%, P: ≤0.010%, S: ≤0.010%, Mo: 0.27-0.03%, Cr: 0.25-0.30%, Nb: 0.1-0.2%, and the remainder is Fe and unavoidable impurities.

[0051] In one embodiment of the present invention, the components of the high manganese steel for cutting teeth include, by mass percentage, C: 1.14-1.35%, Si: 0.50-0.80%, Mn: 13.3-14.0%, P: ≤0.006%, S: ≤0.009%, Mo: 0.28-0.030%, Cr: 0.27-0.30%, Nb: 0.15-0.2%, and the remainder is Fe and unavoidable impurities.

[0052] In one embodiment of the present invention, the components of the high manganese steel for blade teeth of the present invention include, by mass percentage, C: 0.95%, Si: 0.31%, Mn: 11.0%, P: 0.008%, S: 0.007%, Mo: 0.20%, Cr: 0.30%, Nb: 0.01%, and the remainder is Fe and unavoidable impurities.

[0053] In one embodiment of the present invention, the components of the high manganese steel for blade teeth of the present invention include, by mass percentage, C: 0.98%, Si: 0.44%, Mn: 11.6%, P: 0.007, S: 0.004%, Mo: 0.3%, Cr: 0.20%, Nb: 0.10%, and the remainder is Fe and unavoidable impurities.

[0054] In one embodiment of the present invention, the components of the high manganese steel for blade teeth of the present invention include, by mass percentage, C: 1.10%, Si: 0.45%, Mn: 13.3%, P: 0.009%, S: 0.006%, Mo: 0.20%, Cr: 0.30%, Nb: 0.20%, and the remainder is Fe and unavoidable impurities.

[0055] In one embodiment of the present invention, the components of the high manganese steel for blade teeth of the present invention include, by mass percentage, C: 1.14%, Si: 0.48%, Mn: 12.0%, P: 0.006%, S: 0.009%, Mo: 0.20%, Cr: 0.30%, Nb: 0.20%, and the remainder is Fe and unavoidable impurities.

[0056] It should be noted that when the high manganese steel for blade teeth of the present invention is impacted, its surface can produce extremely strong work hardening effect, thereby producing different deformation amounts. As the deformation amount increases (the greater the impact load, the greater the deformation amount), the yield strength, tensile strength and surface hardness increase significantly, and the elongation decreases significantly. This is because during the deformation process of the high manganese steel for blade teeth, the microstructure austenite undergoes TWIP effect due to deformation, and a large number of deformation twins and dislocations appear, which significantly improves the yield strength and tensile strength.

[0057] On the other hand, the present invention also provides a method for preparing high manganese steel for blade teeth, which is used to prepare the above-mentioned high manganese steel for blade teeth, and the preparation method comprises the following steps:

[0058] Step 1, smelting and pouring to obtain a casting blank or an ingot;

[0059] The smelting is carried out by converter, electric furnace or induction furnace, and continuous casting is used to produce billets or mold casting is used to produce ingots.

[0060] Step 2, subjecting the billet or ingot to high temperature homogenization treatment and then forging, and then rolling;

[0061] Step 21, heating the billet or ingot to 1000-1200° C. in a heating furnace, and keeping the temperature at 1000-1200° C. for 0.5-2 h, forging after taking out of the furnace, the temperature during forging is 1000-1200° C., and air cooling to room temperature after forging;

[0062] Step 22, the forged billet or ingot is again loaded into the heating furnace and heated to 1000-1200°C, and kept at 1000-1200°C for 0.5-2h. After being taken out of the furnace, 5-10 passes of rolling are performed, the rolling temperature is 1000-1200°C, the rolling reduction is 5-15%, and the billet or ingot is water-cooled to room temperature after rolling.

[0063] In the above step 21, the billet or ingot is heated to 1000-1200°C and kept warm for 0.5-2h under this condition, which is to ensure that the alloy elements in the billet or ingot are completely dissolved and exist in the matrix in the form of solid solution. Considering that the holding temperature is too high (more than 1200°C) or the holding time is too long (more than 2h), the austenite grains will grow excessively or even overheat, affecting the final performance of the material; the holding temperature is too low or the holding time is too short, resulting in incomplete solid solution of the alloy elements, uneven steel composition, and affecting the performance. Therefore, the present invention strictly controls the heating temperature range of the billet or ingot to be 1000-1200°C and the holding time to be 0.5-2h.

[0064] Step 3, heat treating the steel;

[0065] The above heat treatment is a quenching process; during the quenching process, the steel is heated from room temperature to a complete austenitizing temperature of 1000-1200°C at a heating rate of 1-4°C / S and kept at this temperature for 0.5-1h, and then water-cooled to room temperature.

[0066] Specifically, in the above step 3, during the quenching treatment, the steel is heated to a complete austenitizing temperature of 1000-1200°C and kept warm for 0.5-1h to ensure that the workpiece structure is completely austenitized. Then quench to room temperature to obtain a quenched austenite structure; if the temperature is too high or the holding time is too long, the quenching time will cause the grain growth of high manganese steel. If the fine austenite grains are kept at high temperature for too long, they will become coarse, resulting in a decrease in the toughness and strength of the material; if the holding temperature is too low or the holding time is too short, the steel cannot be completely austenitized, the structure is uneven, and the performance is affected. Therefore, during the quenching treatment, the temperature is controlled in the range of 1000-1200°C, and the holding time is controlled in the range of 0.5-1h.

[0067] Compared with the prior art, the mechanical properties of the steel for dredger blade obtained by the above preparation method are as follows: its yield strength ≥400MPa, tensile strength ≥900MPa, hardness

[0068] ≥20HRC, room temperature impact energy ≥100J; with the impact load, the surface undergoes extremely strong work hardening, with a yield strength ≥1000MPa, a tensile strength ≥1300MPa, and a hardness >50HRC; these are greater than the mechanical properties of the existing dredger blade steel.

[0069] In summary, the present invention optimizes the smelting and heat treatment processes by designing the composition and content of the elements, and finally obtains the structure of austenite + NbC, so that the impact load under working conditions causes the surface to produce extremely strong work hardening effect to achieve mechanical properties that meet the requirements of use.

[0070] Since the cutter teeth of dredgers are mainly used to dig large-sized hard phases such as seabed rocks, there is a great impact pressure between the cutter teeth and the workpiece during operation. Therefore, the present invention adopts high manganese steel (Mn13Nb steel) as the steel for the cutter teeth. The present invention accurately controls the mass percentage of C, Si, Mn, Mo, Cr, and Nb elements in the steel, and combines the heat treatment process to ensure the microstructure of the steel. When the high manganese steel is subjected to impact loads, a strong work hardening effect is produced on the surface, which greatly improves the surface wear resistance while the core still maintains high toughness, ensuring that the high manganese steel cutter teeth have a good match of strength and toughness and excellent wear resistance, and ensuring that the steel of the present invention can meet the service conditions of the cutter teeth.

[0071] Examples 1-4

[0072] Embodiments 1-4 of the present invention provide a method for preparing steel for dredging ship teeth. The components of the steel in embodiments 1-4 include, by mass percentage: C: 0.95-1.35%, Si: 0.30-0.80%, Mn: 11.0-14.0%, P: ≤0.070%, S: ≤0.030%, Mo: 0.2-0.3%, Cr: 0.20-0.30%, Nb: 0.01-0.2%, and the remainder is Fe and unavoidable impurities.

[0073] The method for preparing the steel of Examples 1-4 comprises:

[0074] Step 1, smelting and pouring to obtain a casting blank or an ingot;

[0075] Step 2, subjecting the high manganese steel blade teeth steel billet or ingot to high temperature homogenization treatment and then forging, and then rolling;

[0076] Step 3: heat-treating the rolled billet or ingot, and cooling it to room temperature with water to obtain high manganese steel for blade teeth.

[0077] The specific preparation methods of the steels of Examples 1-4 are shown in Table 1 below, the corresponding components are shown in Table 2, the microstructures are shown in Table 3, and the mechanical properties are shown in Table 4. Among them, the microstructure of Example 1 is shown in Table 1. Figure 1 As shown, the microstructure of Example 2 is as follows Figure 2 As shown, the microstructure of Example 3 is as follows Figure 3 As shown, the microstructure of Example 4 is as follows Figure 4 shown.

[0078] Table 1 Preparation process conditions of Examples 1-4

[0079]

[0080] Table 2 Chemical composition of Examples 1-4

[0081] Element C(％) Si(%) Mn(%) P(％) S(％) Cr(％) Mo(%) Nb(%) Example 1 0.95 0.31 11.0 0.008 0.007 0.30 0.2 0.01 Example 2 0.98 0.44 11.6 0.007 0.004 0.20 0.3 0.1 Example 3 1.10 0.45 13.3 0.009 0.006 0.20 0.3 0.2 Example 4 1.14 0.48 12.0 0.006 0.009 0.30 0.2 0.2 Comparative Example 1 0.81 0.31 7.0 0.008 0.007 0.70 0.2 0.01 Comparative Example 2 0.72 0.44 6.6 0.007 0.004 0.90 0.3 0.1 Comparative Example 3 0.65 0.45 8.3 0.009 0.006 1.20 0.3 0.2 Comparative Example 4 0.63 0.48 6.0 0.006 0.009 1.30 0.2 0.2

[0082] Table 3 Microstructure of Examples 1-4

[0083] Serial number Microstructure Example 1 Austenite + second phase NbC Example 2 Austenite + second phase NbC Example 3 Austenite + second phase NbC Example 4 Austenite + second phase NbC Comparative Example 1 Austenite + second phase NbC + M7C3 Comparative Example 2 Austenite + second phase NbC + M7C3 Comparative Example 3 Austenite + second phase NbC + M7C3 Comparative Example 4 Austenite + second phase NbC + M7C3

[0084] It can be seen from Table 3 above that the presence of carbide M7C3 in the microstructure of the steel for the blade teeth of Comparative Examples 1 to 4 results in a relatively weak strong work hardening effect when impacted. Compared with Comparative Examples 1 to 4, since the microstructure of the present invention does not contain carbides, the surface of the high manganese steel for the blade teeth of the present invention can produce a strong work hardening effect when impacted, thereby producing different deformation amounts. As the deformation amount increases (the greater the impact load, the greater the deformation amount), the yield strength, tensile strength and surface hardness increase significantly, and the elongation decreases significantly. This is because during the deformation process of the high manganese steel for the blade teeth, the microstructure austenite undergoes the TWIP effect due to deformation, and a large number of deformation twins and dislocations appear, which significantly improves the yield strength and tensile strength.

[0085] Table 4 Mechanical properties of steels of Examples 1-4

[0086]

[0087] It can be concluded from Table 4 above that the yield strength of the high manganese steel used for blade teeth of the present invention is 492-669MPa; the tensile strength is 977-1146MPa; the hardness is 26-29HRC; the room temperature impact energy is 100-105J; according to the actual working conditions, the yield strength of the high manganese steel used for blade teeth of the present invention is ≥1000MPa, the tensile strength is ≥1300MPa, and the hardness is >50HRC, and its strength and toughness can meet the requirements of dredger blade teeth and extend the service life of the blade teeth; this is because as the impact load causes the surface to produce extremely strong work hardening, its microstructure austenite undergoes TWIP effect (twin induced plasticity effect) due to deformation, and a large number of deformation twins and dislocations appear, which significantly improves the yield strength and tensile strength. During the plastic deformation process of high manganese steel, the high strain zone will induce twin transformation due to strain, which significantly delays the necking phenomenon of the steel, thereby greatly improving the plasticity of the steel.

[0088] In summary, the present invention optimizes the elements and proportions of high manganese steel teeth as well as the smelting and heat treatment processes, and finally obtains the structure of austenite + NbC, so that the impact load under working conditions causes the surface to produce extremely strong work hardening effect to achieve mechanical properties that meet the requirements of use.

[0089] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A high manganese steel for knife teeth, characterized in that: Its components include, by mass percentage, C: 0.95-1.35%, Si: 0.30-0.80%, Mn: 11.0-14.0%, P: ≤0.070%, S: ≤0.030%, Mo: 0.20-0.30%, Cr: 0.020-0.030%, Nb: 0.01-0.2%, and the balance is Fe and inevitable impurities.

2. The high manganese steel for blade teeth according to claim 1, characterized in that: The components of the high manganese steel for blade teeth include, by mass percentage, C: 0.98-1.35%, Si: 0.31-0.80%, Mn: 11.0-14.0%, P: ≤0.040%, S: ≤0.020%, Mo: 0.25-0.30%, Cr: 0.23-0.30%, Nb: 0.04-0.2%, and the remainder is Fe and unavoidable impurities.

3. The high manganese steel for knife teeth according to claim 2, characterized in that: The components of the high manganese steel for blade teeth include, by mass percentage, C: 1.0-1.35%, Si: 0.44-0.80%, Mn: 12.0-14.0%, P: ≤0.010%, S: ≤0.010%, Mo: 0.27-0.30%, Cr: 0.25-0.30%, Nb: 0.1-0.2%, and the remainder is Fe and unavoidable impurities.

4. The high manganese steel for blade teeth according to claim 3, characterized in that: The components of the high manganese steel for blade teeth include, by mass percentage, C: 1.14-1.35%, Si: 0.50-0.80%, Mn: 13.3-14.0%, P: ≤0.006%, S: ≤0.009%, Mo: 0.28-0.30%, Cr: 0.27-0.30%, Nb: 0.15-0.2%, and the remainder is Fe and unavoidable impurities.

5. The high manganese steel for blade teeth according to claim 1, characterized in that: The components of high manganese steel for blade teeth include, by mass percentage, C: 0.95%, Si: 0.31%, Mn: 11.0%, P: 0.008%, S: 0.007%, Mo: 0.020%, Cr: 0.30%, Nb: 0.01%, and the remainder is Fe and unavoidable impurities.

6. The high manganese steel for blade teeth according to claim 1, characterized in that: The microstructure of the high manganese steel for blade teeth is high manganese austenite and the second phase NbC.

7. A method for preparing high manganese steel for blade teeth, characterized in that: For preparing the high manganese steel for blade teeth according to any one of claims 1 to 6, the preparation method comprises the following steps: Step 1, smelting and pouring the obtained high manganese steel blade steel billet or ingot; Use converter, electric furnace or induction furnace for smelting, and use continuous casting to produce billets or mold casting to produce ingots; Step 2, subjecting the high manganese steel blade teeth steel billet or ingot to high temperature homogenization treatment and then forging, and then rolling; Step 3: heat-treating the rolled billet or ingot, and cooling it to room temperature with water to obtain high manganese steel for blade teeth.

8. The method for preparing high manganese steel for blade teeth according to claim 7, characterized in that: In step 2, the billet or ingot is first heated to 1000-1200° C. in a heating furnace, and kept at 1000-1200° C. for a certain period of time, and then forged after being taken out of the furnace, and then air-cooled to room temperature after forging.

9. The method for preparing high manganese steel for blade teeth according to claim 8, characterized in that: In step 2, the insulation time is 0.5 to 2 hours.

10. The method for preparing high manganese steel for blade teeth according to claim 7, characterized in that: In the step 3, the cast billet or ingot after high temperature homogenization treatment is quenched; The process includes heating the billet or ingot from room temperature to its complete austenitization temperature and keeping the temperature for a certain period of time, then cooling it with water to room temperature, and finally obtaining high manganese steel for knife teeth.

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