Wear-resistant cast steel for low-cost high-toughness cement grinding disc lining plate of vertical mill and preparation method of wear-resistant cast steel

Abstract

The invention provides wear-resistant cast steel for a low-cost high-toughness cement grinding disc lining plate of a vertical mill and a preparation method, and relates to the technical field of wear-resistant cast steel for the low-cost high-toughness cement grinding disc lining plate of the vertical mill. The alloy comprises the following components in percentage by weight: 0.55%-0.60% of C, 1.0%-1.2% of Mn, 1.5%-1.8% of Si, 1.8%-2.0% of Cr, 0.3%-0.5% of Mo, 0.003%-0.006% of B, 0.04%-0.06% of Nb, 0.01%-0.03% of Ti, 0.01%-0.03% of Y and the balance of Fe and inevitable impurities. Through component content selection, tapping temperature regulation and control, quenching and tempering treatment, the low-cost and high-toughness wear-resistant cast steel for the grinding disc lining plate of the cement vertical mill is obtained; the method is simple and easy to operate, green and environment-friendly, low in cost, short in process, high in efficiency and beneficial to industrial large-scale production and popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wear-resistant steel casting in the broken grinding equipment industry, and particularly relates to a low-cost high-toughness wear-resistant cast steel for a cement vertical mill grinding disc lining plate and a preparation method. BACKGROUND

[0002] With the development of equipment manufacturing industry towards large-scale, high efficiency and harsh working conditions, the wear and failure problem of relative motion parts is increasingly serious, which not only leads to cost increase and production decrease, but also puts forward higher requirements on the material performance of equipment parts. In the building material industry, the grinding disc lining plate as a key component, directly contacts with the material and bears the grinding of hard particles when grinding the material, so it is severely worn and needs to be frequently hardfaced or replaced, thereby affecting the operation efficiency of the mill.

[0003] According to the standard requirements of GB / T 35167-2017 "Cement Vertical Roller Mill", the hardness of the wear-resistant layer working surface of the easily-worn parts in the cement vertical mill should not be less than 58HRC. At present, the grinding roller and grinding disc parts used in the vertical mill mainly include cast parts and hardfaced parts, and the chemical composition of the wear-resistant layer of the parts is mainly high-carbon high-chromium alloy cast iron series, in addition, some ceramic composite materials are also applied to such parts. However, the high-carbon high-chromium alloy cast iron, which uses hard carbide as a wear-resistant phase to play a wear-resistant role, is prone to cracks during use or welding due to the strong fragmentation of carbide to the matrix, thereby affecting the reliability and service life of the parts.

[0004] With the development of material science, medium and low alloy composite wear-resistant steel has become a new hotspot in material research and development, which has high strength and high hardness, outstanding performance in wear resistance, high cost performance, and broad prospects in wear-resistant application field, and is expected to promote breakthroughs in wear-resistant material technology and wide application.

[0005] Chinese patent CN108570537A discloses a production method of high-hardness low-alloy cast steel parts, the high-hardness low-alloy cast steel parts are cooled in a 10-15% PAG quenching liquid after being kept at 840-880℃ for 1-3h, and then tempered at 450-560℃, and the hardness is only 340-370HB, far from reaching the use standard of 58HRC, and the quenching medium has certain requirements, resulting in cost increase.

[0006] Chinese patent CN110157974A discloses a high-hardness high-boron wear-resistant cast steel and a preparation method thereof, the high-hardness high-boron wear-resistant cast steel is directly water-cooled to room temperature at 180-250℃ for 30-50min from as-cast state, the prepared high-hardness high-boron wear-resistant cast steel has a hardness of 55-68HRC and an impact toughness of 2.9-5.5J·cm -2Although the hardness meets the standard for vertical mill use, the boron content of 1.5-3.0wt.% may induce boron brittleness, resulting in low tensile strength, plasticity and toughness of the steel, which limits its application.

[0007] Chinese patent CN114381666A discloses a high-carbon high-chromium cast steel for ball mill cylinder liner and a heat treatment method thereof. The high-carbon high-chromium cast steel is normalized at 1050-1150℃ for 2-3h and air-cooled to room temperature, then quenched at 900-1000℃ for 1-1.5h and oil-cooled or air-cooled to room temperature, and finally tempered at 200-250℃ for 2-2.5h and air-cooled to room temperature. The hardness of the high-carbon high-chromium cast steel after heat treatment is 54.5-58.9HRC, and the impact toughness is 2.7-3.7J·cm -2 The heat treatment process is complicated, increasing the time and energy costs. In addition, the high chromium content of 9-10wt.% results in high cost, poor comprehensive economy and performance.

[0008] There are some other technical solutions that use composition improvement and full annealing + tempering process to improve the hardness of the liner, but the yield ratio, elongation and impact toughness cannot be improved simultaneously with the increase of tensile strength. Some other technical solutions first prepare a preform, then separate and finish grinding, and finally obtain the finished product through sintering, air quenching and low-temperature tempering. Therefore, the comprehensive performance is not improved through the addition of alloying elements or through the process, and the improvement of hardness is realized by embedding hard alloy plates on the surface of the plate. Some other technical solutions use laser deposition to prepare wear-resistant vertical mill liners, but the strength is difficult to guarantee, and the hardness and impact toughness cannot be improved simultaneously. SUMMARY

[0009] To solve the technical problems in the prior art that the preparation method of the traditional cement vertical mill grinding disc liner wear-resistant cast steel cannot improve the hardness, yield strength, impact toughness and other properties simultaneously, the heat treatment method or the preparation method is complicated, the operation difficulty is high, the cost is high, and the efficiency is low, the present application provides a V-Ti composite micro-alloyed wear-resistant manganese steel and a heat treatment method. The technical solution is as follows: A low-cost high-toughness cement vertical mill grinding disc liner wear-resistant cast steel, the composition of the low-cost high-toughness cement vertical mill grinding disc liner wear-resistant cast steel is as follows: C 0.55-0.60%, Mn 1.0-1.2%, Si 1.5-1.8%, Cr 1.8-2.0%, Mo 0.3-0.5%, B 0.003-0.006%, Nb 0.04-0.06%, Ti 0.01-0.03%, Y 0.01-0.03%, and the balance is Fe and unavoidable impurities.

[0010] Optionally, the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel has a structure of bainite with a volume fraction of 31.9±8.2%, martensite with a volume fraction of 67.7±7.7%, and residual austenite with a volume fraction of 0.5±0.3%.

[0011] Optionally, the bainite has a shape of lower bainite and a small amount of granular bainite, and an average size of 2.05-4.07 μm; the martensite has a shape of flaky medium-carbon martensite, and an average size of 3.20-8.02 μm; and the residual austenite has a shape of blocky and granular, and an average size of 0.38-1.18 μm.

[0012] Optionally, the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel has a tensile strength of 1049-1134 MPa, an elongation of 0.5±0.3%, a hardness of 58.1-64.0 HRC, and a v-notch impact toughness of 7.3-14.8 J·cm -2 .

[0013] A preparation method of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel, and the preparation method comprises the following steps: S1, raw material weighing and smelting: the raw materials are selected and weighed according to the component content of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel, a vacuum induction furnace is used for smelting, pure iron is first melted, and manganese iron, chromium iron, molybdenum iron and boron iron are added for alloying, and at the same time, desulfurization, deoxidization, detection and adjustment of the chemical element content are performed; S2, tapping and pouring: the molten steel obtained by the vacuum induction furnace smelting in S1 is tapped at a temperature above the alloy liquidus line temperature of 140-180℃, Nb, Ti and Y are added for modification treatment 10 min before tapping, when the temperature drops to a pouring temperature above the alloy liquidus line temperature of 40-60℃, the molten steel is poured into a metal mold cavity, and after natural cooling, the mold is opened and the castings are cleaned to obtain the cast steel; S3, air cooling quenching treatment: the cast steel in S2 is subjected to air cooling quenching treatment to obtain quenched cast steel; S4, tempering treatment: the quenched cast steel in S3 is subjected to tempering treatment to obtain the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel.

[0014] Optionally, the liquidus line temperature of the cast steel in S1 is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, wherein the element symbols represent the mass percentage content, and the liquidus line temperature range of the wear-resistant cast steel is 1480-1490℃.

[0015] Optionally, the temperature of the tapping in S2 is 1620-1670 DEG C, and the pouring temperature is 1520-1550 DEG C.

[0016] Optionally, the tensile strength of the cast steel in S2 is 584+ / -73 MPa, the elongation is 0.1+ / -0.1%, the hardness is 44.5+ / -3.9 HRC, and the v-notch impact toughness is 5.3+ / -1.6 J*cm -2 .

[0017] Optionally, the quenching holding temperature in S3 is 850-1000 DEG C, the holding time is 2h, and then air cooling to room temperature.

[0018] Optionally, the tensile strength of the cast steel in S3 is 1173-1637 MPa, the hardness is 59.8-64.5 HRC, and the v-notch impact toughness is 3.6-4.3 J*cm -2 .

[0019] Optionally, the tempering temperature in S4 is 200-350 DEG C, the tempering time is 1.5h, and then air cooling to room temperature.

[0020] Technical principle of the application: In the niobium micro-alloyed steel, titanium can also form many small precipitates, which can produce strong precipitation strengthening effect to further increase the yield strength. In addition, when the niobium content is more than 0.036 wt%, the strength of the titanium-niobium micro-alloyed steel is mainly controlled by the Ti content, and the increase of the Nb content has no significant effect. Nb and Ti can also reduce the temper brittleness to ensure the toughness of the product.

[0021] Rare earth elements can refine and purify grains and grain boundaries, which can obviously help the cast steel. Studies have shown that Y can improve the mechanical properties of low alloy steel weld metal, reduce the number of inclusions, and improve the low temperature impact toughness. Therefore, Y-based heavy rare earth is used in the design.

[0022] The application adopts composite modification treatment of Nb, Ti and Y, wherein Nb is 0.035-0.06 wt.%, Ti is 0.01-0.03 wt.%, Y is 0.015-0.03 wt.%, and 0.05 wt.% < Nb+Ti < 0.08 wt.% is ensured, so as to maximize the role of Nb, Ti and Y in improving the mechanical properties on the premise of controlling the cost.

[0023] The application is to improve the hardenability of cast steel, make the pearlite transformation curve far away from the bainite transformation curve, add Cr and Mo elements to the steel, when the content of Cr is less than 4wt%, the addition of Cr in the steel can improve the thermal conductivity of the steel, about 2wt% Mo can form spherical carbide, thereby improving the thermal conductivity of the cast steel. Therefore, the ratio of Cr to Mo is selected to be about 2:1, and the addition of Mn can correspondingly replace the role of Mo, so that the wear-resistant cast steel contains 1.8-2.0wt.% of Cr and 0.3-0.5wt.% of Mo.

[0024] The research of the application shows that the addition of trace boron in the cast steel can significantly improve the hardenability of the steel, the grain boundary energy of the steel can be reduced by the grain boundary segregation of B, the formation of ferrite is delayed, and the diffusion of grain boundary atoms is also blocked by the boron atoms on the grain boundary, thereby increasing the hardenability. However, the cast steel containing boron is prone to "boron brittleness" phenomenon in practical application, that is, the impact toughness and hardenability fluctuate greatly. Therefore, the content of B is determined to be 0.003-0.006wt.%.

[0025] In the wear-resistant cast steel, carbon in the form of interstitial solid solution significantly improves the strength and hardness of the steel, and at the same time reduces the bainite and martensite transformation temperature (Bs and Ms points), in order to obtain the balance of strength and toughness and hardenability, the medium carbon content component is selected, and the carbon content is 0.55-0.60wt.%. Silicon can improve toughness by replacing solid solution strengthening matrix and inhibiting carbide precipitation, and at the same time, it can improve hardenability in cooperation with elements such as manganese and chromium, but too high silicon content (>2.2wt%) will generate blocky ferrite to reduce hardness. It has been found that a medium carbon steel with a silicon content of about 1.5wt% can obtain good plasticity, toughness and hardness after quenching and tempering, so the silicon content is selected to be 1.5-1.8wt.%.

[0026] Compared with the prior art, the above technical scheme has at least the following beneficial effects: The above scheme provides a low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel and a preparation method, which can solve the technical problems in the prior art, such as the inability of the traditional cement vertical mill grinding disc lining plate wear-resistant cast steel preparation method to simultaneously improve hardness, yield strength, impact toughness and other properties, the complexity of the heat treatment method or the preparation method, the high cost and low efficiency.

[0027] Compared with the traditional medium-high manganese wear-resistant steel (Mn≥3wt.%), the application controls the content of Mn to be small, reduces the content of residual austenite, and through the air cooling quenching + low temperature tempering two-step process, bainite and martensite dual-phase structure can be prepared; in addition, Mn can reduce the bainite and martensite transformation temperature of the steel, and can partially replace the role of Mo in the steel to reduce the production cost.

[0028] The tapping and pouring temperature control of the application can make the microstructure of the obtained cast steel avoid coarse grains caused by too high temperature, and also prevent pouring defects caused by too low temperature, so as to obtain fine and uniform as-cast grains. The subsequent heat treatment is difficult to greatly change the grain size of the original as-cast state, and during quenching heating, the fine as-cast grains can be converted into fine austenite grains. The size of the austenite grains directly determines the size and morphology of the phases such as martensite and bainite generated after cooling. Uniform grains make the phase change occur synchronously and uniformly in the entire casting, and the refined as-cast structure provides an ideal initial state for subsequent heat treatment, so that the final structure is finer and the performance is more uniform.

[0029] The air cooling quenching treatment of the application can make the microstructure of the obtained quenched cast steel be a mixed structure of undercooled austenite transformed martensite and bainite. Martensite is a supersaturated solid solution of carbon in alpha-Fe, which is a hard phase; bainite is a structure with good combination of toughness and strength. The complex phase structure composed of the two provides excellent strength basis for the material.

[0030] The tempering treatment of the application can make the unstable martensite in the microstructure of the obtained low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel precipitate fine carbides and be converted into more stable tempered martensite. The added micro-alloying elements Nb and Ti can form fine carbonitrides during tempering, produce precipitation strengthening, and also help to stabilize the structure. In addition, internal stress can be eliminated, the impact toughness of the material is greatly improved, and a balance between high hardness and high impact toughness is achieved.

[0031] The application can make the obtained high-hardness wear-resistant cast steel for cement vertical mill grinding disc lining plate achieve a good balance between hardness and toughness, with a hardness of 58.1-64.0HRC and a v-notch impact toughness of 7.3-14.8J·cm -2 , which represents a significant improvement in performance.

[0032] The application adopts vacuum induction furnace melting, controls the key process parameters such as tapping temperature, pouring temperature, and heat treatment temperature and time, and makes the whole preparation process precise and efficient.

[0033] The application has simple process, reduces time and energy cost, improves production efficiency, is conducive to large-scale industrial production, avoids the problems of boron embrittlement of high-boron cast steel and high cost of high-chromium cast steel, and has better economy and applicability.

[0034] In summary, compared with other traditional methods, the method of the application selects component content, regulates tapping temperature, and performs quenching and tempering treatment to obtain low-cost high-toughness wear-resistant cast steel for cement vertical mill grinding disc lining plate. The method is simple, easy to operate, green, low in cost, short in process, high in efficiency, and conducive to large-scale industrial production and promotion. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative effort based on these drawings.

[0036] Figure 1 is a cast microstructure diagram of a low-cost high-toughness wear-resistant cast steel for a cement vertical mill grinding disc lining plate according to Embodiment 1 of the present application; Figure 2 is a microstructure diagram after heat treatment (1000-300) of a low-cost high-toughness wear-resistant cast steel for a cement vertical mill grinding disc lining plate according to Embodiment 1 of the present application; Figure 3 is a microstructure diagram after heat treatment (900-200) of a low-cost high-toughness wear-resistant cast steel for a cement vertical mill grinding disc lining plate according to Embodiment 2 of the present application. DETAILED DESCRIPTION

[0037] The technical solutions in the present application will be described below with reference to the drawings.

[0038] In the embodiments of the present application, the words such as “example”, “for example” are used to represent as an example, illustration or description. Any embodiment or design scheme described as “example” in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word “example” is intended to present the concept in a specific manner. In addition, in the embodiments of the present application, the meaning expressed by “and / or” can be both, or can be either one of the two.

[0039] In the embodiments of the present application, “image” and “picture” can be used interchangeably at times. It should be pointed out that when the distinction is not emphasized, the meanings expressed are consistent.

[0040] In the embodiments of the present application, sometimes the subscript such as W1 can be written in the form of non-subscript such as W1. When the distinction is not emphasized, the meanings expressed are consistent.

[0041] In order to make the technical problems, technical solutions and advantages of the present application more clear, the following will be described in detail with reference to the drawings and specific embodiments.

[0042] The low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel has the following components in percentage by mass: C 0.55-0.60%, Mn 1.0-1.2%, Si 1.5-1.8%, Cr 1.8-2.0%, Mo 0.3-0.5%, B 0.003-0.006%, Nb 0.04-0.06%, Ti 0.01-0.03%, Y 0.01-0.03%, and the balance of Fe and inevitable impurities.

[0043] The volume fraction of the bainite is 31.9±8.2%, the volume fraction of the martensite is 67.7±7.7%, and the volume fraction of the residual austenite is 0.5±0.3%.

[0044] In particular, the microstructure of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel is as follows: the volume fraction of the bainite is 31.9±8.2%, the volume fraction of the martensite is 67.7±7.7%, and the volume fraction of the residual austenite is 0.5±0.3%.

[0045] In particular, the shape of the bainite is lower bainite and a small amount of granular bainite, and the average size is 2.05-4.07 μm; the shape of the martensite is flaky medium-carbon martensite, and the average size is 3.20-8.02 μm; and the shape of the residual austenite is blocky and granular, and the average size is 0.38-1.18 μm.

[0046] In particular, the tensile strength of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel is 1049-1134 MPa, the elongation is 0.5±0.3%, the hardness is 58.1-64.0 HRC, and the v-notch impact toughness is 7.3-14.8 J·cm -2 .

[0047] A preparation method of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel, which specifically comprises the following steps: S1, raw material weighing and smelting: the raw materials are selected and weighed according to the component content of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel, and a vacuum induction furnace is used for smelting, pure iron is first melted, and manganese iron, chromium iron, molybdenum iron and boron iron are added for alloying, and at the same time, desulfurization, deoxidization, detection and adjustment of the chemical element content are performed; S2, tapping and pouring: the molten steel obtained by the vacuum induction furnace smelting of S1 is tapped at a temperature above the alloy liquidus temperature of 140-180 ℃, Nb, Ti and Y are added for modification treatment 10 min before tapping, when the temperature drops to a pouring temperature above the alloy liquidus temperature of 40-60 ℃, the molten steel is poured into a metal mold cavity, and after natural cooling, the mold is opened and the castings are cleaned to obtain the cast steel. S3, air cooling quenching treatment: the cast steel of S2 is subjected to air cooling quenching treatment to obtain quenched cast steel; S4, tempering treatment: the quenched cast steel of S3 is subjected to tempering treatment to obtain low-cost high-toughness cement vertical mill grinding disc liner plate wear-resistant cast steel.

[0048] In particular, the liquidus temperature of the cast steel in S1 is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, wherein the element symbols represent the mass percentage content, and the liquidus temperature interval of the wear-resistant cast steel is 1480-1490℃.

[0049] In particular, the tapping temperature in S2 is 1620-1670℃, and the pouring temperature is 1520-1550℃.

[0050] In particular, the tensile strength of the cast steel in S2 is 584±73MPa, the elongation is 0.1±0.1%, the hardness is 44.5±3.9HRC, and the v-notch impact toughness is 5.3±1.6J·cm -2 .

[0051] In particular, the quenching holding temperature in S3 is 850-1000℃, and the holding time is 2h, followed by air cooling to room temperature.

[0052] In particular, the tensile strength of the cast steel in S3 is 1173-1637MPa, the hardness is 59.8-64.5HRC, and the v-notch impact toughness is 3.6-4.3J·cm -2 .

[0053] In particular, the tempering temperature in S4 is 200-350℃, and the tempering time is 1.5h, followed by air cooling to room temperature.

[0054] Example 1

[0055] A low-cost high-toughness cement vertical mill grinding disc liner plate wear-resistant cast steel according to the present embodiment, wherein the composition of the low-cost high-toughness cement vertical mill grinding disc liner plate wear-resistant cast steel is as follows in terms of mass percentage: C 0.58%, Mn 1.16%, Si 1.54%, Cr 1.86%, Mo 0.41%, B 0.0041%, Nb 0.049%, Ti 0.015%, Y 0.014%, and the balance is Fe and unavoidable impurities.

[0056] A preparation method based on the low-cost high-toughness cement vertical mill grinding disc liner plate wear-resistant cast steel, which comprises the following steps: S1, raw material weighing and smelting: according to the above-mentioned low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel component content selection of raw materials and ratio weighing, using vacuum induction furnace smelting first melt pure iron, and add manganese iron, chromium iron, molybdenum iron, boron iron alloying, at the same time, desulfurization, deoxidation, detection and adjustment of chemical element content; the liquidus temperature of cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, the element symbol in the formula represents its mass percentage, and the liquidus temperature interval of wear-resistant cast steel is 1480-1490℃; S2, tapping and pouring: the molten steel obtained by vacuum induction furnace smelting of S1 is tapped at 1620-1670℃, Nb, Ti and Y are added 10min before tapping for modification treatment, and when the temperature is above the alloy liquidus temperature, the pouring temperature is 1520-1550℃, the mold cavity is poured into the metal mold, and the castings are cleaned after natural cooling and opening the box, and the cast steel is obtained; the as-cast structure is shown in Figure 1 The tensile strength of the cast steel is 584MPa, the hardness is 44.5HRC, and the v-notch impact toughness is 5.3J·cm -2 ; S3, air cooling quenching treatment: the cast steel of S2 is cut into a heat treatment sample with a size of 25mmx25mmx70mm, and air cooling quenching treatment is carried out, the quenching holding temperature is 1000℃, the holding time is 2h, and then air cooling to room temperature, and the quenched cast steel is obtained; The tensile strength of the quenched cast steel is 1473MPa, the hardness is 59.2HRC, and the v-notch impact toughness is 3.8J·cm -2 ; S4, tempering treatment: the quenched cast steel of S3 is subjected to tempering treatment, the tempering temperature is 300℃, the tempering time is 1.5h, and then air cooling to room temperature, and the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel is obtained.

[0057] The microstructure of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment is shown in Figure 2 The microstructure of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment is shown in

[0058] The tensile strength of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment is 1364MPa, the elongation is 0.5%, the hardness is 58.1HRC, and the v-notch impact toughness is 14.8J·cm -2 .​

[0059] Embodiment 2

[0060] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel according to the embodiment has the following components in terms of mass percentage: C 0.58%, Mn 1.16%, Si 1.54%, Cr 1.86%, Mo 0.41%, B 0.0041%, Nb 0.049%, Ti 0.015%, Y 0.014%, and the balance of Fe and inevitable impurities.

[0061] A preparation method of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel, which specifically includes the following steps: S1, raw material weighing and smelting: the raw materials are selected and weighed according to the component content of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel, and a vacuum induction furnace is used for smelting. Pure iron is first melted, and manganese iron, chromium iron, molybdenum iron, and boron iron are added for alloying. At the same time, desulfurization, deoxidization, detection, and adjustment of the chemical element component content are performed. The liquidus temperature of the cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, where the element symbols represent their mass percentage content. The liquidus temperature range of the wear-resistant cast steel is 1480-1490℃. S2, tapping and pouring: the molten steel obtained by the vacuum induction furnace smelting of S1 is tapped at 1620-1670℃. Nb, Ti, and Y are added for modification treatment 10 minutes before tapping. When the temperature drops above the alloy liquidus temperature, the pouring temperature is 1520-1550℃, and the molten steel is poured into a metal mold cavity. After natural cooling, the mold is opened and the castings are cleaned to obtain the cast steel. The tensile strength of the cast steel is 584MPa, the hardness is 44.5HRC, and the v-notch impact toughness is 5.3J·cm -2 ; S3, air cooling quenching treatment: the cast steel of S2 is cut into a heat-treated sample with a size of 25mm×25mm×70mm, and air cooling quenching treatment is performed. The quenching holding temperature is 900℃, and the holding time is 2h. Then, air cooling is performed to room temperature to obtain the quenched cast steel. The tensile strength of the quenched cast steel is 1265MPa, the hardness is 64.5HRC, and the v-notch impact toughness is 4.1J·cm -2 ; S4, tempering treatment: the quenched cast steel of S3 is subjected to tempering treatment at a tempering temperature of 200℃ for 1.5h, and then air cooling is performed to room temperature to obtain the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel.

[0062] The microstructure of the low-cost, high-toughness cement vertical mill grinding disc liner prepared in this embodiment is as follows: Figure 3 As shown, the composition consists of 23.6% bainite, 76.2% martensite, and 0.2% retained austenite by volume. The bainite is lower bainite with an average size of 2.05 μm. The martensite is plate-like medium-carbon martensite with an average size of 8.02 μm. The retained austenite is granular with an average size of 0.59 μm.

[0063] The wear-resistant cast steel used for the low-cost, high-toughness cement vertical mill grinding disc liner prepared in this embodiment has a tensile strength of 777 MPa, an elongation of 0.3%, a hardness of 64.1 HRC, and a v-shaped impact toughness of 7.3 J·cm. -2 .

[0064] Example 3

[0065] This embodiment discloses a low-cost, high-toughness wear-resistant cast steel for a cement vertical mill grinding disc liner. The composition of the low-cost, high-toughness wear-resistant cast steel for a cement vertical mill grinding disc liner, by mass percentage, is: C 0.58%, Mn 1.16%, Si 1.54%, Cr 1.86%, Mo 0.41%, B 0.0041%, Nb 0.049%, Ti 0.015%, Y 0.014%, with the balance being Fe and unavoidable impurities.

[0066] A method for preparing wear-resistant cast steel for grinding disc liners of a low-cost, high-toughness cement vertical mill, comprising the following specific steps: S1. Raw material weighing and smelting: Select and weigh the raw materials according to the composition of the wear-resistant cast steel for the grinding disc liner of the low-cost, high-toughness cement vertical mill mentioned above. First, melt the pure iron using a vacuum induction furnace, and then add ferromanganese, ferrochrome, ferromolybdenum, and ferroboron for alloying. At the same time, desulfurize, deoxidize, test, and adjust the chemical element composition. The liquidus temperature of the cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, where the element symbols in the formula represent their mass percentage content. The resulting liquidus temperature range of the wear-resistant cast steel is 1480-1490℃. S2. Steel tapping and casting: The molten steel obtained from the vacuum induction furnace in S1 is tapped at 1620-1670℃. Nb, Ti and Y are added 10 minutes before tapping for modification treatment. When the temperature drops to above the alloy liquidus temperature and the casting temperature is 1520-1550℃, it is poured into the cavity of the metal mold. After natural cooling, the mold is opened and the casting is cleaned to obtain cast steel. The cast steel has a tensile strength of 584 MPa, a hardness of 44.5 HRC, and a v-shaped impact toughness of 5.3 J·cm.-2 ; S3, air cooling quenching treatment: cutting the heat-treated sample of S2 cast steel with a size of 25mmx25mmx70mm, air cooling quenching treatment, quenching holding temperature is 850℃, holding time is 2h, then air cooling to room temperature, obtaining quenched cast steel; The tensile strength of the quenched cast steel is 1348MPa, the hardness is 62.7HRC, and the v-notch impact toughness is 3.9J·cm -2 ; S4, tempering treatment: tempering treatment of the quenched cast steel of S3, tempering temperature is 300℃, tempering time is 1.5h, then air cooling to room temperature, obtaining low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel.

[0067] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment has a microstructure of 30.6% bainite, 69.2% martensite, and 0.2% residual austenite in volume fraction; the shape of the bainite is lower bainite and a small amount of granular bainite, and the average size is 2.20μm; the shape of the martensite is flaky medium-carbon martensite, and the average size is 4.97μm; the shape of the residual austenite is granular, and the average size is 0.38μm.

[0068] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment has a tensile strength of 1173MPa, an elongation of 0.4%, a hardness of 58.5HRC, and a v-notch impact toughness of 7.7J·cm -2 .

[0069] Example 4

[0070] A low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel of this embodiment, the composition of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel is as follows in terms of mass percentage: C 0.57%, Mn 1.17%, Si 1.52%, Cr 1.98%, Mo 0.35%, B 0.0057%, Nb 0.041%, Ti 0.028%, Y 0.0098%, and the balance is Fe and unavoidable impurities.

[0071] A preparation method based on the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel, the preparation method of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel is as follows: S1, raw material weighing and smelting: according to the above-mentioned low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel component content selection of raw materials and ratio weighing, using vacuum induction furnace smelting first melt pure iron, and add manganese iron, chromium iron, molybdenum iron, boron iron alloying, at the same time, desulfurization, deoxidation, detection and adjustment of chemical element content; the liquidus temperature of cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, the element symbol in the formula represents its mass percentage, and the liquidus temperature interval of wear-resistant cast steel is 1480-1490℃; S2, tapping and pouring: the molten steel obtained by vacuum induction furnace smelting of S1 is tapped at 1620-1670℃, Nb, Ti and Y are added 10min before tapping for modification treatment, and when the temperature is above the alloy liquidus temperature, the pouring temperature is 1520-1550℃, the mold cavity is poured into the metal mold, and the casting is cleaned after natural cooling and opening the box, and the cast steel is obtained. The tensile strength of the cast steel is 596MPa, the hardness is 46.3HRC, and the v-notch impact toughness is 4.9J·cm -2 ; S3, air cooling quenching treatment: the cast steel of S2 is cut into a heat treatment sample with a size of 25mmx25mmx70mm, air cooling quenching treatment is carried out, the quenching holding temperature is 900℃, the holding time is 2h, and then air cooling to room temperature, and the quenched cast steel is obtained. The tensile strength of the quenched cast steel is 1637MPa, the hardness is 60.4HRC, and the v-notch impact toughness is 3.6J·cm -2 ; S4, tempering treatment: the quenched cast steel of S3 is subjected to tempering treatment, the tempering temperature is 350℃, the tempering time is 1.5h, and then air cooling to room temperature, and the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel is obtained.

[0072] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment has a microstructure of 22.7% bainite and 77.3% martensite; the shape of the bainite is lower bainite, and the average size is 3.31μm; the shape of the martensite is flaky medium-carbon martensite, and the average size is 6.41μm.

[0073] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in this embodiment has a tensile strength of 1570MPa, an elongation of 0.5%, a hardness of 58.1HRC, and a v-notch impact toughness of 14.1J·cm -2 .

[0074] Example 5

[0075] The embodiment is a low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel, and the composition of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel is as follows in terms of mass percentage: C 0.546%, Mn 0.998%, Si 1.547%, Cr 1.965%, Mo 0.344%, B 0.0046%, Nb 0.048%, Ti 0.023%, Y 0.01%, and the balance is Fe and inevitable impurities.

[0076] A preparation method of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel, and the preparation method of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel specifically includes the following steps: S1, raw material weighing and smelting: the raw materials are selected and proportioned according to the composition content of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel, a vacuum induction furnace is used for smelting, pure iron is first melted, and manganese iron, chromium iron, molybdenum iron, and boron iron are added for alloying, and at the same time, desulfurization, deoxidization, detection, and adjustment of the chemical element composition content are performed; the liquidus temperature of the cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, wherein the element symbols represent the mass percentage content, and the liquidus temperature interval of the wear-resistant cast steel is 1480-1490℃; S2, tapping and pouring: the molten steel obtained by the vacuum induction furnace smelting of S1 is tapped at 1620-1670℃, Nb, Ti, and Y are added for modification treatment 10 minutes before tapping, and when the temperature drops above the alloy liquidus temperature, the pouring temperature is 1520-1550℃, the molten steel is poured into a metal mold cavity, and after natural cooling, the mold is opened and the castings are cleaned to obtain the cast steel; The tensile strength of the cast steel is 588MPa, the hardness is 42.9HRC, and the v-notch impact toughness is 5.8J·cm -2 ; S3, air cooling quenching treatment: the cast steel of S2 is cut into a heat-treated sample with a size of 25mm×25mm×70mm, and air cooling quenching treatment is performed, the quenching holding temperature is 900℃, the holding time is 2h, and then air cooling is performed to room temperature to obtain quenched cast steel; The tensile strength of the quenched cast steel is 1448MPa, the hardness is 61.7HRC, and the v-notch impact toughness is 4.1J·cm -2 ; S4, tempering treatment: the quenched cast steel of S3 is subjected to tempering treatment, the tempering temperature is 250℃, the tempering time is 1.5h, and then air cooling is performed to room temperature to obtain the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel.

[0077] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in the embodiment has a microstructure of 31.9% in volume fraction of bainite, 67.7% in volume fraction of martensite, and 0.5% in volume fraction of residual austenite; the bainite has a shape of lower bainite and an average size of 4.07 μm; the martensite has a shape of flaky medium-carbon martensite and an average size of 3.2 μm; and the residual austenite has a shape of block and an average size of 1.18 μm.

[0078] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in the embodiment has a tensile strength of 1049 MPa, an elongation of 0.5%, a hardness of 59.8 HRC, and a v-notch impact toughness of 11.1 J·cm -2 .

[0079] Comparative Example 1

[0080] The low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel prepared in the embodiment has a tensile strength of 1049 MPa, an elongation of 0.5%, a hardness of 59.8 HRC, and a v-notch impact toughness of 11.1 J·cm

[0081] A preparation method of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel, the preparation method of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel specifically includes the following steps: S1, raw material weighing and smelting: the raw materials are selected and proportioned according to the component content of the cement vertical mill grinding disc lining plate wear-resistant cast steel, and a vacuum induction furnace is used for smelting. Pure iron is first melted, and manganese iron, chromium iron, molybdenum iron, and boron iron are added for alloying. At the same time, desulfurization, deoxidization, detection, and adjustment of the chemical element component content are performed. The liquidus temperature of the cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, wherein the element symbols represent the mass percentage content. The liquidus temperature interval of the wear-resistant cast steel is 1480-1490℃. S2, tapping and pouring: the molten steel obtained by the vacuum induction furnace smelting of S1 is tapped at 1620-1670℃. Nb, Ti, and Y are added for modification treatment 10 min before tapping. When the temperature drops to above the alloy liquidus temperature, the pouring temperature is 1520-1550℃, and the molten steel is poured into a metal mold cavity. After natural cooling, the mold is opened and the castings are cleaned to obtain the cast steel. The cast steel has a tensile strength of 653 MPa, a hardness of 50.7 HRC, and a v-notch impact toughness of 1.93 J·cm -2 ; S3. Air-cooled quenching treatment: A heat-treated sample of 25mm×25mm×70mm was cut from the S2 cast steel and subjected to air-cooled quenching treatment. The quenching temperature was 900℃ and the holding time was 2h. Then it was air-cooled to room temperature to obtain the quenched cast steel. The tensile strength of the quenched cast steel is 1652 MPa, the hardness is 64.3 HRC, and the v-shaped impact toughness is 0.96 J·cm. -2 ; S4. Tempering treatment: The quenched cast steel of S3 is tempered at a temperature of 250℃ for 1.5h, and then air-cooled to room temperature to obtain wear-resistant cast steel for cement vertical mill grinding disc liner.

[0082] The wear-resistant cast steel used for the cement vertical mill grinding disc liner prepared in this comparative example has a microstructure of 99.6% martensite by volume and 0.4% retained austenite by volume; the martensite is lath-shaped with an average size of 5.9 μm; the retained austenite is blocky with an average size of 0.79 μm.

[0083] The wear-resistant cast steel used for the grinding disc liner of the cement vertical mill prepared in this comparative example has a tensile strength of 1340 MPa, an elongation of 0.1%, a hardness of 56.3 HRC, and a v-shaped impact toughness of 2.4 J·cm. -2 .

[0084] Comparative Example 2

[0085] This comparative example describes a wear-resistant cast steel for a cement vertical mill grinding disc liner. The composition of the wear-resistant cast steel for the cement vertical mill grinding disc liner, by mass percentage, is: C 0.546%, Mn 0.998%, Si 1.547%, Cr 1.965%, Mo 0.344%, B 0.0046%, Nb 0.048%, Ti 0.023%, Y 0.01%, with the balance being Fe and unavoidable impurities.

[0086] A method for preparing wear-resistant cast steel for cement vertical mill grinding disc liners, comprising the following steps: S1. Raw material weighing and smelting: Select and weigh the raw materials according to the composition of the wear-resistant cast steel for the cement vertical mill grinding disc liner. First, melt the pure iron using a vacuum induction furnace, and then add ferromanganese, ferrochrome, ferromolybdenum, and ferroboron for alloying. At the same time, desulfurize, deoxidize, test, and adjust the chemical element composition. The liquidus temperature of the cast steel is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, where the element symbols in the formula represent their mass percentage content. The resulting liquidus temperature range of the wear-resistant cast steel is 1480-1490℃. S2. Steel tapping and casting: The molten steel obtained from the vacuum induction furnace in S1 is tapped at 1620-1670℃. Nb, Ti and Y are added 10 minutes before tapping for modification treatment. When the temperature drops to above the alloy liquidus temperature and the casting temperature is 1520-1550℃, it is poured into the cavity of the metal mold. After natural cooling, the mold is opened and the casting is cleaned to obtain cast steel. The cast steel has a tensile strength of 596 MPa, a hardness of 46.3 HRC, and a v-shaped impact toughness of 4.9 J·cm. -2 ; S3. Air-cooled quenching treatment: A heat-treated sample of 25mm×25mm×70mm was cut from the S2 cast steel and subjected to air-cooled quenching treatment. The quenching temperature was 900℃ and the holding time was 2h. Then it was air-cooled to room temperature to obtain the quenched cast steel. The tensile strength of the quenched cast steel is 1383 MPa, the hardness is 52.7 HRC, and the v-shaped impact toughness is 4.2 J·cm. -2 ; S4. Tempering treatment: The quenched cast steel of S3 is tempered at a temperature of 250℃ for 1.5h, and then air-cooled to room temperature to obtain wear-resistant cast steel for cement vertical mill grinding disc liner.

[0087] The wear-resistant cast steel used for the cement vertical mill grinding disc liner prepared in this comparative example has a microstructure consisting of 41.4% bainite, 58.4% martensite, and 0.2% retained austenite by volume. The bainite is lower bainite with an average size of 2.62 μm. The martensite is plate-shaped medium-carbon martensite with an average size of 3.59 μm. The retained austenite is blocky with an average size of 1.82 μm.

[0088] The wear-resistant cast steel used for the grinding disc liner of the cement vertical mill prepared in this comparative example has a tensile strength of 1093 MPa, an elongation of 0.5%, a hardness of 45.5 HRC, and a v-shaped impact toughness of 18.6 J·cm. -2 .

[0089] The above-mentioned solution proposes a low-cost, high-toughness wear-resistant cast steel for cement vertical mill grinding disc liners and its preparation method. It can solve the technical problems existing in the prior art, such as the inability of traditional methods for preparing wear-resistant cast steel for cement vertical mill grinding disc liners to synergistically improve hardness, yield strength, impact toughness and other properties, complex heat treatment methods or preparation methods, high operation difficulty, high cost and low efficiency.

[0090] Compared with traditional medium-high manganese wear-resistant steel (Mn≥3wt.%), this invention reduces the content of retained austenite by controlling the Mn content to a smaller level. A two-step process of air-cooled quenching + low-temperature tempering can be used to prepare a dual-phase structure of bainite and martensite. In addition, Mn can lower the phase transformation temperature of bainite and martensite in steel, and can partially replace the role of Mo in steel to reduce production costs.

[0091] The steel pouring temperature control of this invention enables the resulting cast steel to avoid grain coarsening caused by excessively high temperatures and pouring defects caused by excessively low temperatures, thereby obtaining fine and uniform as-cast grains. The refined as-cast microstructure provides an ideal initial state for subsequent heat treatment, resulting in more uniform final properties.

[0092] The air-cooling quenching treatment of this invention enables the quenched cast steel to have a microstructure of mixed martensite and bainite formed by the transformation of supercooled austenite. Martensite is a supersaturated solid solution of carbon in α-Fe and is a hard phase; bainite, on the other hand, is a microstructure that combines toughness and strength well. The multiphase microstructure composed of these two phases provides an excellent strength basis for the material.

[0093] The tempering treatment of this invention enables the unstable martensite in the microstructure of the wear-resistant cast steel used for the low-cost, high-toughness cement vertical mill grinding disc liner to precipitate fine carbides, transforming it into more stable tempered martensite. The added microalloying elements Nb and Ti form fine carbonitrides during tempering, resulting in precipitation strengthening and contributing to microstructure stability. Furthermore, it eliminates internal stress, significantly improving the material's impact toughness and contributing to a balance between high hardness and high impact toughness.

[0094] This invention enables the production of cement vertical mill grinding disc liners using high-hardness wear-resistant cast steel, achieving a good balance between hardness and toughness, with a hardness reaching 58.1-64.0 HRC and a v-tooth impact toughness reaching 7.3-14.8 J·cm. -2 This reflects a significant improvement in performance.

[0095] This invention employs vacuum induction furnace melting and controls key process parameters such as tapping temperature, casting temperature, and heat treatment temperature and time, making the entire preparation process precise and efficient.

[0096] The present invention has a simple process, reduces time and energy costs, improves production efficiency, and is conducive to large-scale industrial production. At the same time, it avoids the boron embrittlement phenomenon of high boron cast steel and the high cost of high chromium cast steel, making it more economical and applicable.

[0097] In summary, compared with other traditional methods, the method of this invention obtains low-cost, high-toughness wear-resistant cast steel for cement vertical mill grinding disc liners through component content selection, steel tapping temperature control, quenching and tempering treatment. This method is simple to operate, environmentally friendly, low-cost, short process, and high-efficiency, which is conducive to large-scale industrial production and promotion.

[0098] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0099] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0100] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0101] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A low-cost high-toughness wear-resistant cast steel for a cement vertical mill grinding table liner plate, characterized in that, The composition of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel according to mass percentage: C 0.55-0.60%, Mn 1.0-1.2%, Si 1.5-1.8%, Cr 1.8-2.0%, Mo 0.3-0.5%, B 0.003-0.006%, Nb 0.04-0.06%, Ti 0.01-0.03%, Y 0.01-0.03%, and the balance of Fe and inevitable impurities.

2. The low cost high toughness cement mill liner plate wear resistant cast steel according to claim 1, characterized in that, The microstructure of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel is 31.9±8.2% of bainite, 67.7±7.7% of martensite, and 0.5±0.3% of residual austenite.

3. The low cost high toughness cement mill liner plate wear resistant cast steel according to claim 2, characterized in that, The shape of the bainite is lower bainite and a small amount of granular bainite, and the average size is 2.05-4.07μm; the shape of the martensite is flaky medium-carbon martensite, and the average size is 3.20-8.02μm; the shape of the residual austenite is blocky and granular, and the average size is 0.38-1.18μm.

4. The low cost high toughness cement mill liner plate of abrasion resistant cast steel as claimed in claim 2, wherein, The tensile strength of the low-cost high-toughness cement vertical mill grinding disc lining plate wear-resistant cast steel is 1049-1134 MPa, the elongation is 0.5±0.3%, the hardness is 58.1-64.0 HRC, and the v-notch impact toughness is 7.3-14.8 J·cm -2 .

5. A method of manufacturing a wear-resistant cast steel for a liner plate of a grinding table of a low-cost high-toughness cement vertical mill based on the low-cost high-toughness cement vertical mill grinding table liner plate wear-resistant cast steel according to claim 1, characterized by, The preparation method of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel comprises the following steps: S1, raw material weighing and smelting: selecting raw materials according to the composition content of the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel, and weighing and mixing, smelting in a vacuum induction furnace, first melting pure iron, and adding manganese iron, chromium iron, molybdenum iron, and boron iron for alloying, and simultaneously carrying out desulfurization, deoxidization, detection, and adjusting the chemical element content; S2, tapping and pouring: tapping the molten steel obtained by the vacuum induction furnace smelting of S1 at 140-180℃ above the alloy liquidus temperature, adding Nb, Ti, and Y for modification treatment 10min before tapping, pouring into a metal mold cavity when the temperature drops to 40-60℃ above the alloy liquidus temperature, opening the box after natural cooling, and cleaning the castings to obtain the cast steel; S3, air cooling quenching treatment: air cooling quenching treatment of the cast steel of S2 to obtain quenched cast steel; S4, tempering treatment: tempering treatment of the quenched cast steel of S3 to obtain the low-cost high-toughness cement vertical mill grinding disc lining wear-resistant cast steel.

6. A method of producing a low-cost, high-toughness, cement vertical mill grinding table liner plate wear-resistant cast steel according to claim 5, characterized in that, The liquidus temperature of the cast steel in S1 is calculated according to the formula TL=1539-65C-8Si-5Mn-30P-25S-1.5Cr-2Mo, where the element symbols represent their mass percentage content, and the liquidus temperature range of the wear-resistant cast steel is 1480-1490℃.

7. A method of producing a low-cost, high-toughness, cement vertical mill grinding table liner plate wear-resistant cast steel according to claim 5, characterized in that, The temperature of the tapping in S2 is 1620-1670℃, and the pouring temperature is 1520-1550℃.

8. A method of producing a low-cost, high-toughness cement vertical mill grinding table liner plate wear-resistant cast steel according to claim 5, characterized in that, The tensile strength of the cast steel in S3 is 1173-1637 MPa, the hardness is 59.8-64.5 HRC, and the v-notch impact toughness is 3.6-4.3 J·cm -2 .

9. The method of producing a low-cost high-toughness cement vertical mill grinding table liner plate wear-resistant cast steel according to claim 5, characterized in that, The quenching holding temperature in S3 is 850-1000℃, and the holding time is 2h, and then air cooling to room temperature.

10. A method of producing a low cost high toughness cement vertical mill grinding table liner plate wear resistant cast steel as claimed in claim 5, characterized by, The tempering temperature in S4 is 200-350℃, the tempering time is 1.5h, and then air cooling to room temperature.

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