A preparation method of high chromium cast iron arc liner

Abstract

The present invention discloses a method for preparing a high-chromium cast iron arc liner, belonging to the field of arc liner processing and preparation. The method comprises the following steps: S1: raw material smelting; S2: composite modification treatment, in which rare earth magnesium alloy, ferrovanadium, and ferroboron are added to the bottom of a molten iron ladle, the molten iron is then poured into the ladle for casting, and the casting is removed after cooling; S3: thermal correction treatment plus composite quenching treatment, in which the casting is heated and placed in a correction processing mold for correction treatment while cooling water is passed through the correction processing mold. After cooling for a period of time, the casting is removed, placed in an oil pool for oil cooling, and then air-cooled to room temperature; S4: tempering treatment, in which the casting is placed in a heating furnace, heated to 280-300°C, kept at this temperature for 3-4 hours, removed from the furnace, and air-cooled to room temperature; S5: inspection and storage, thereby obtaining the desired arc liner casting. The present invention can achieve thermal correction and rapid cooling of the arc liner while reducing cooling time and improving the performance of the arc liner.

Description

Technical Field

[0001] The invention belongs to the field of arc lining plate processing and preparation, and more specifically, relates to a preparation method of a high-chromium cast iron arc lining plate. Background Art

[0002] like Figure 2 As shown, the arc liner is a critical wear-resistant component installed on concrete mixers. Its cross-section is arc-shaped, consisting of an inner arc surface and an outer arc surface. The outer arc surface is provided with a mounting boss and a mounting hole in the center. Arc liner is produced using a casting method. During the casting process, the casting deforms due to pouring and shrinkage, resulting in an unacceptable arc radii, which must be corrected.

[0003] The arc liner is obtained by casting. During the casting process, the casting deforms due to pouring and shrinkage, making the arc liner unqualified and requiring correction. However, the material of the arc liner has very poor plasticity at room temperature. If it is corrected at room temperature, it will break. Therefore, it cannot be corrected at room temperature and must be heated to a certain temperature before it can be corrected. When heated to the point where the matrix structure is completely transformed into austenite, the plasticity is greatly improved, and correction operations will not cause it to break. Maintaining the force to maintain its shape and then rapidly cooling it can ensure that the arc does not rebound after correction, ensuring that the arc liner is qualified.

[0004] However, if a reasonable thermal correction processing method is not adopted, the arc lining plate may have qualified arc radian but unqualified hardness after processing, and it needs to be quenched again, which will inevitably reduce production efficiency, increase energy consumption and increase production costs.

[0005] It has been determined that when using a correction mold to perform thermal correction on the arc liner with cooling water, the cooling rate for the high-temperature arc liner can reach 5-8°C / second. This cooling rate is slower than the cooling rate of oil cooling during the arc liner quenching process, but much faster than the cooling rates of air cooling and forced air cooling. Therefore, if the cooling effect of the correction mold can be properly utilized, and thermal correction and rapid cooling are performed simultaneously, the arc liner can meet the required hardness requirements while ensuring the arc liner's roundness is qualified. However, as the arc liner's temperature decreases during the treatment process, the cooling rate gradually decreases, causing the treatment time at this stage to be extended to 4-8 minutes. This not only reduces production efficiency, but also requires the untreated arc liner to continue to be kept warm. As the number of pieces to be processed increases, the holding time of the untreated arc liner in the heating furnace gradually increases, resulting in a decrease in hardness and even failure. At the same time, due to the decrease in cooling rate, the thermal correction and cooling time are prolonged, which may cause the arc liner to rebound during the thermal correction process. Since the arc liner is in a state of being pressed by the correction processing mold, the rebound of the arc liner will be prevented by the correction processing mold, causing a large internal stress in the local position where the arc liner contacts the correction processing mold, resulting in a large gap between the surface and the core of the arc liner after processing, a decrease in toughness and even cracks.

[0006] The Chinese patent application number is CN201921218497.9, and the publication date is April 14, 2020. The patent document discloses a curved liner processing mold, which belongs to the field of processing mold technology. The utility model includes a fixed mold and a movable mold. The fixed mold is provided with a concave working surface, and the two ends of the concave working surface are respectively provided with lateral limit blocks, and the top is also provided with a longitudinal limit platform; the movable mold is provided with a convex working surface that cooperates with the concave working surface; wherein, the fixed mold and the movable mold are respectively provided with a water inlet and a water outlet, and a cooling channel is provided between the water inlet and the water outlet. The cooling channel is used to pass cooling water to cool the curved liner. The utility model cools the curved liner after the curvature is corrected, thereby ensuring that the curvature of the curved liner does not rebound and that the circular curvature of the curved liner is qualified. This processing mold belongs to the aforementioned correction processing mold with cooling effect. In actual operation, this processing mold has the series of problems mentioned above caused by the cooling time being extended as the temperature of the curved liner decreases. Summary of the Invention

[0007] 1. Problems to be solved

[0008] In view of the problem that when the existing arc liner correction processing mold is used to correct the high chromium cast iron arc liner, the performance of the prepared arc liner is affected due to the long cooling time. The present invention provides a preparation method of the high chromium cast iron arc liner. By improving the steps of molten iron treatment, thermal correction treatment and quenching treatment of the arc liner, it is possible to reduce the cooling time and improve the performance of the arc liner while achieving thermal correction + rapid cooling treatment of the arc liner.

[0009] 2. Technical solution

[0010] To solve the above problems, the present invention adopts the following technical solutions.

[0011] A method for preparing a high chromium cast iron arc liner comprises the following steps:

[0012] S1: Raw material smelting

[0013] The raw materials are added into the medium frequency induction furnace in sequence for melting. When all the raw materials are melted, the content of each element in the molten iron is detected and adjusted to the set ratio;

[0014] S2: Composite deterioration treatment

[0015] Add rare earth magnesium alloy, ferrovanadium and ferroboron to the bottom of the ladle, then pour the molten iron into the ladle for pouring at a pouring temperature of 1420-1480°C. After the casting cools, take out the casting;

[0016] S3: Thermal correction treatment + composite quenching treatment

[0017] The casting is placed in a heating furnace and heated to 980-1020°C. After keeping the temperature for 2-4 hours, it is taken out and placed in a correction mold for correction. The pressure is maintained for 30-50 seconds. At the same time, cooling water is passed through the correction mold and cooled to 800-850°C at a cooling rate of 5-8°C / second. The casting is then taken out and placed in an oil pool. The oil is cooled to 150-180°C, then taken out and air-cooled to room temperature.

[0018] S4: Tempering

[0019] Place the casting into a heating furnace, heat it to 280-300°C, keep it warm for 3-4 hours, then take it out of the furnace and air cool it to room temperature;

[0020] S5: Inspection and storage to obtain the required arc liner castings.

[0021] As a further improvement of the technical solution, in step S1, the components and mass percentages of the raw materials are: C: 2.6-2.8%, Si: 0.8-1.0%, Mn: 0.6-0.8%, Cr: 18.0-20.0%, Mo: 0.4-0.6%, Cu: 0.8-1.2%, P≤0.03%, S≤0.03%, and the rest are iron and unavoidable impurities.

[0022] As a further improvement of the technical solution, in step S2, the components and mass percentages of the rare earth magnesium alloy are: RE: 6.0-8.0%, Mg: 7.0-9.0%, Ca: 2.0-3.0%, Si≤44.0%, and the rest are iron and unavoidable impurities. The amount of rare earth magnesium alloy added is 0.3-0.35% of the total mass of the molten iron.

[0023] As a further improvement of the technical solution, in step S2, the components and mass percentages of ferrovanadium are: V: 48.0-55.0%, the rest are iron and inevitable impurities, and the amount of ferrovanadium added is 0.1-0.15% of the total mass of the molten iron.

[0024] As a further improvement of the technical solution, in step S2, the components and mass percentages of ferroboron are: B: 19.0-21.0%, the rest are iron and unavoidable impurities, and the amount of ferroboron added is 0.15-0.2% of the total mass of the molten iron.

[0025] As a further improvement of the technical solution, in step S3, the specific process of heating the casting is: placing the arc liner casting into a heating furnace at room temperature, heating it to 650-700°C at a heating rate of 60-80°C / hour, and keeping it warm for 2-3 hours; then heating it to 980-1020°C at a heating rate of 120-150°C / hour, and keeping it warm for 2-4 hours.

[0026] As a further improvement of the technical solution, in step S3, the flow rate of cooling water introduced into the processing mold is calibrated to be 30 to 50 kg / min.

[0027] As a further improvement of the technical solution, the correction processing mold includes a fixed mold and a movable mold, the fixed mold is provided with a concave working surface, and the movable mold is provided with a convex working surface matching the concave working surface; wherein, the fixed mold and the movable mold are also respectively provided with a fixed mold cooling channel and a movable mold cooling channel for passing cooling water to cool the wear-resistant arc lining.

[0028] As a further improvement of the technical solution, the fixed mold and the movable mold are respectively installed on the workbench through the fixed mold flange and the movable mold flange.

[0029] As a further improvement of the technical solution, the workbench is a hydraulic press, which is transmission-connected to the movable mold to drive the movable mold to correct the curvature of the wear-resistant arc liner.

[0030] 3. Beneficial effects

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention discloses a method for preparing a high-chromium cast iron arc liner. By rationally and uniquely improving the design of molten iron composition, molten iron treatment steps, casting thermal correction and quenching treatment steps, the method solves the problem that the quenching cooling time of the existing correction processing mold is too long, which affects the performance of the arc liner. While ensuring that the arc liner correction cooling does not rebound, the quenching cooling time is effectively reduced, and an arc liner casting with qualified arc degree, hardness and toughness is obtained, thereby improving the comprehensive performance of the arc liner. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a structural schematic diagram of the arc liner correction processing mold of the present invention;

[0034] Figure 2 It is a structural schematic diagram of the arc liner of the present invention;

[0035] In the figure: 100, fixed mold; 110, concave working surface; 120, fixed mold cooling channel; 130, fixed mold flange; 200, movable mold; 210, convex working surface; 220, movable mold cooling channel; 230, movable mold flange. DETAILED DESCRIPTION

[0036] Exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and that various changes may be made to the invention without departing from the spirit and scope of the invention. The following more detailed description of the embodiments of the invention is not intended to limit the scope of the claimed invention, but is merely for illustrative and non-limiting purposes, to describe the features and characteristics of the invention, to set forth the best mode for carrying out the invention, and to enable those skilled in the art to practice the invention. Therefore, the scope of the invention is limited solely by the appended claims.

[0037] Example 1

[0038] A method for preparing a high-chromium cast iron arc liner can realize the preparation and deformation correction processing of the high-chromium cast iron arc liner, and no springback occurs during the deformation correction.

[0039] Before introducing the preparation method, in order to more conveniently understand the process of the method, the structure of the correction processing mold used in the method is first described. Figure 1As shown, the correction processing mold includes a fixed mold 100 and a movable mold 200. The fixed mold 100 is provided with a concave working surface 110. The concave working surface 110 and the outer arc surface of the arc lining plate are as shown in FIG. Figure 2 The movable mold 200 is provided with a convex working surface 210 that matches the concave working surface 110. The convex working surface 210 and the inner arc surface of the arc lining plate are as shown. Figure 2 The concave working surface 110 of the fixed mold 100 and the convex working surface 210 of the movable mold 200 cooperate, allowing the curved liner to be clamped between the fixed mold 100 and the movable mold 200, thereby further correcting the curvature of the curved liner. The fixed mold 100 is provided with a fixed mold cooling channel 120, and the movable mold 200 is provided with a movable mold cooling channel 220, for passing cooling water to cool the curved liner, thereby ensuring that the curvature of the curved liner does not rebound and that the circular curvature of the curved liner is qualified.

[0040] The fixed mold 100 is provided with a fixed mold flange 130, and the movable mold 200 is provided with a movable mold flange 230. Both are mounted on a workbench via the fixed mold flange 130 and the movable mold flange 230, respectively. In this embodiment, the workbench is a hydraulic press, which is in transmission connection with the movable mold 200 and drives the movable mold 200 to correct the curvature of the wear-resistant arc liner.

[0041] The specific steps and technical effects of the arc liner preparation method are described in detail below.

[0042] S1: Raw material smelting

[0043] The raw materials are sequentially added to a medium frequency induction furnace for melting. After all the raw materials are melted, the content of each element in the molten iron is detected and adjusted to a set ratio, i.e., the set ratio of each component in the raw materials. In this step, the components and mass percentages of the raw materials are: C: 2.6-2.8%, Si: 0.8-1.0%, Mn: 0.6-0.8%, Cr: 18.0-20.0%, Mo: 0.4-0.6%, Cu: 0.8-1.2%, P ≤ 0.03%, S ≤ 0.03%, and the remainder is iron and unavoidable impurities.

[0044] In this step, different from the conventional oil-cooled quenching process, the selected carbon content is slightly higher, because the quenching process is a composite quenching process, and the cooling period of the high temperature stage after leaving the heating furnace is indirect water cooling of the mold, and the cooling rate is less than the cooling rate of direct oil cooling, and the crack tendency caused by rapid cooling is reduced. The solid solution strengthening effect of silicon is stronger than that of manganese, nickel, chromium, and molybdenum, but it will increase the brittle transition temperature of the material, and the content should not be too high. The ratio of the selected chromium content to the carbon content is about 7, and the carbide type is mainly M7C3 type. In combination with other alloying elements and appropriate heat treatment, castings with higher hardness and better toughness can be obtained. The role of molybdenum is to shift the continuous cooling transformation curve of high chromium cast iron to the right, strongly delaying the pearlite transformation of austenite. The role of copper is to extend the incubation period for austenite to transform into pearlite and bainite. When added in combination with molybdenum, the effect is better than adding molybdenum alone. The composition design of this embodiment makes the casting material have satisfactory hardenability, which is conducive to obtaining castings with high hardness and a small difference in hardness between the inside and outside. In addition, it prolongs the pearlite incubation period, so that the casting has sufficient time to complete various operations of the composite quenching treatment and avoid the occurrence of non-martensitic transformations that are not conducive to improving hardness.

[0045] S2: Composite deterioration treatment

[0046] Rare earth magnesium alloy, ferrovanadium, and ferroboron are added to the bottom of a molten iron ladle. The molten iron is then poured into the ladle for casting at a temperature of 1420-1480°C. The casting is removed after cooling. The components and mass percentages of the rare earth magnesium alloy are as follows: RE: 6.0-8.0%, Mg: 7.0-9.0%, Ca: 2.0-3.0%, Si ≤ 44.0%, with the remainder being iron and unavoidable impurities. The amount of rare earth magnesium alloy added is 0.3-0.35% of the total mass of the molten iron. The components and mass percentages of ferrovanadium are as follows: V: 48.0-55.0%, with the remainder being iron and unavoidable impurities. The amount of ferrovanadium added is 0.1-0.15% of the total mass of the molten iron. The components and mass percentages of ferroboron are as follows: B: 19.0-21.0%, with the remainder being iron and unavoidable impurities. The amount of ferroboron added is 0.15-0.2% of the total mass of the molten iron.

[0047] In this step, composite modifier changes the nucleation and growth conditions of carbide, suppresses the growth trend of its preferential trend, weakens the anisotropy of its growth, and after modification treatment, carbide distribution is significantly changed, so that matrix grain refinement is achieved, and carbide form and size are changed, which is conducive to improving the hardness, strength and toughness of casting material. Rare earth, vanadium and boron are both modifiers and alloying elements, which can form hard carbide, or are dissolved in the matrix, which is conducive to improving the hardness, strength and toughness of casting material. And molten iron can be purified to reduce inclusions.

[0048] S3: Thermal correction treatment + composite quenching treatment

[0049] The arc liner casting is placed in a heating furnace at room temperature and heated to 650-700°C at a rate of 60-80°C / hour, holding at this temperature for 2-3 hours. Next, it is heated to 980-1020°C at a rate of 120-150°C / hour, held at this temperature for 2-4 hours, removed from the furnace, and placed in a calibration mold for calibration. Pressure is maintained for 30-50 seconds while cooling water is passed through the calibration mold, cooling it to 800-850°C at a rate of 5-8°C / second at a cooling water flow rate of 30-50 kg / min. The casting is then removed from the furnace, placed in an oil bath, and cooled to 150-180°C. After cooling to room temperature, it is removed from the furnace and placed in an air-cooling area. Forced air cooling is then performed to the room temperature.

[0050] It should be noted that the oil pool in this embodiment has a capacity of 12 cubic meters. A circulating water cooling device is installed at the bottom and around the oil pool, allowing cooling water to be passed through to reduce the temperature of the oil pool. Furthermore, temperature measuring devices are installed around the oil pool to monitor temperature fluctuations at all times. Furthermore, a conveyor roller with adjustable length and height is installed between the oil pool and the calibration mold to quickly lower the arc liner, which has undergone thermal calibration and indirect mold water cooling, into the oil pool.

[0051] The specific process for correcting the arc liner by machining the mold is as follows: first, the fixed mold 100 and movable mold 200 are mounted on a hydraulic press. Then, the arc liner, heated to 980-1020°C, is placed on the fixed mold 100. The hydraulic press drives the movable mold 200 to move so that the convex working surface 210 of the movable mold 200 fully contacts the inner arc surface of the arc liner, while the hydraulic press maintains pressure. During the pressure-maintaining process, the arc liner is cooled using cooling water, and its surface temperature is measured simultaneously. In this embodiment, an infrared thermometer is used for temperature measurement. When the surface temperature of the arc liner reaches 800-850°C, the hydraulic press drives the movable mold 200 to move away from the arc liner and remove the arc liner. In this embodiment, both the fixed mold 100 and movable mold 200 are made of heat-resistant steel, and the hydraulic press is a 100-ton four-column hydraulic press.

[0052] Furthermore, the hydraulic press of this embodiment is located 4 meters from the heating furnace, shortening the time required to remove the parts from the furnace and place them in the correction mold. Furthermore, a column-type cantilever crane is installed between the hydraulic press and the box-type electric heating furnace. The boom can be rotated, allowing the arc liner to be lifted using a hook, then rotated and placed on the concave working surface 110 of the fixed mold 100. This operation can be completed in 8 to 10 seconds. This allows for rapid removal of the parts, followed by pressurization and rapid cooling, ensuring a more complete transformation from austenite to martensite during quenching, thus facilitating the production of high-hardness arc liner castings. Furthermore, the removal process is more convenient, shortening the transition time between each part being removed from the furnace and the start of pressurization, ensuring stable and consistent product quality. This reduces the workload on operators and prevents accidents such as dropped workpieces, burns, and injuries.

[0053] In this step, the heating process includes two stages. In the first heating stage, the heating rate should not be too high to avoid thermal cracking. The heat preservation is a pre-pearlitization treatment to allow the secondary carbides in the cast structure to be fully precipitated. In the second heating stage, the plasticity of the material is greatly improved. Increasing the heating rate can speed up production. The heat preservation in this heating stage can cause carbon and chromium to dissolve from the austenite to form dispersed secondary carbides. S Points are improved.

[0054] The quenching process in this step differs from conventional quenching and is divided into water quenching during the mold correction phase and oil quenching after removal. During the water quenching phase, the austenite in the matrix undergoes no structural transformation, resulting in undercooled austenite. During the oil quenching phase, the cooling rate is ≥9°C / second, and the undercooled austenite transforms into martensite, eutectic carbides, carbides, and a small amount of retained austenite.

[0055] The cooling water quenching phase during the mold correction process benefits from the optimization of the previous composition design, molten iron treatment steps, and two heating stages. This prolongs the pearlite incubation period, allowing sufficient time to complete the operations from removal to oil cooling, and to obtain a supercooled austenite matrix structure. This effectively reduces the quenching time while ensuring that the arc liner correction cooling does not cause springback, resulting in arc liner castings with qualified arc radian, hardness, and toughness, improving the overall performance of the arc liner.

[0056] S4: Tempering

[0057] The casting is placed in a heating furnace and heated to 280-300°C. After holding for 3-4 hours, it is removed from the furnace and air-cooled to room temperature. The purpose of the tempering treatment is to reduce the residual stress of the arc liner, improve the toughness, and enhance the feasibility of the arc liner under impact load.

[0058] S5: Inspection and storage to obtain the required arc liner castings.

[0059] The high-chromium cast iron arc liner of this embodiment has been tested to have a hardness of 60-63 HRc, with a hardness difference of no more than 0.3 HRc between the surface and the core, fully meeting the requirements of the part. Metallographic testing has revealed a microstructure consisting of martensite + eutectic carbide + secondary carbide + a small amount of retained austenite. Mechanical property testing has shown an impact toughness of 3.5 J / cm 2 .

Claims

1. A method for preparing a high chromium cast iron arc liner, characterized in that: The following steps are involved: S1: Raw material smelting The raw materials are added into the medium frequency induction furnace in sequence for melting. When all the raw materials are melted, the content of each element in the molten iron is detected and adjusted to the set ratio; S2: Composite deterioration treatment Add rare earth magnesium alloy, ferrovanadium and ferroboron to the bottom of the ladle, then pour the molten iron into the ladle for pouring at a pouring temperature of 1420-1480°C. After the casting cools, take out the casting; S3: Thermal correction treatment + composite quenching treatment The casting is placed in a heating furnace and heated to 980-1020°C. After keeping the temperature for 2-4 hours, it is taken out and placed in a correction mold for correction. The pressure is maintained for 30-50 seconds. At the same time, cooling water is passed through the correction mold and cooled to 800-850°C at a cooling rate of 5-8°C / second. The casting is then taken out and placed in an oil pool. The oil is cooled to 150-180°C, then taken out and air-cooled to room temperature. The correction processing mold comprises a fixed mold (100) and a movable mold (200), wherein the fixed mold (100) is provided with a concave working surface (110), and the movable mold (200) is provided with a convex working surface (210) matching the concave working surface (110); wherein the fixed mold (100) and the movable mold (200) are further provided with a fixed mold cooling channel (120) and a movable mold cooling channel (220) respectively, for passing cooling water to cool the wear-resistant arc liner; The specific process of the correction processing mold for correcting the curvature of the arc lining plate is as follows: first, the fixed mold (100) and the movable mold (200) are installed on the oil hydraulic press, and then the arc lining plate heated to 980-1020° C. is placed on the fixed mold (100), and the oil hydraulic press drives the movable mold (200) to move so that the convex working surface (210) of the movable mold (200) is completely in contact with the inner arc surface of the arc lining plate, and the oil hydraulic press performs pressure maintenance at the same time; when the surface temperature of the arc lining plate is 800-850° C., the oil hydraulic press drives the movable mold (200) to move away from the arc lining plate, and the arc lining plate is taken out; S4: Tempering Place the casting into a heating furnace, heat it to 280-300°C, keep it warm for 3-4 hours, then take it out of the furnace and air cool it to room temperature; S5: Inspection and storage to obtain the required arc liner castings.

2. The method for preparing a high chromium cast iron arc liner according to claim 1, characterized in that: In step S1, the components and mass percentages of the raw materials are: C: 2.6-2.8%, Si: 0.8-1.0%, Mn: 0.6-0.8%, Cr: 18.0-20.0%, Mo: 0.4-0.6%, Cu: 0.8-1.2%, P≤0.03%, S≤0.03%, and the rest are iron and unavoidable impurities.

3. The method for preparing a high chromium cast iron arc liner according to claim 2, characterized in that: In step S2, the components and mass percentages of the rare earth magnesium alloy are: RE: 6.0-8.0%, Mg: 7.0-9.0%, Ca: 2.0-3.0%, Si≤44.0%, and the rest are iron and unavoidable impurities. The amount of rare earth magnesium alloy added is 0.3-0.35% of the total mass of the molten iron.

4. The method for preparing a high chromium cast iron arc liner according to claim 3, characterized in that: In step S2, the components and mass percentages of ferrovanadium are: V: 48.0-55.0%, and the rest are iron and inevitable impurities. The amount of ferrovanadium added is 0.1-0.15% of the total mass of molten iron.

5. The method for preparing a high chromium cast iron arc liner according to claim 4, characterized in that: In step S2, the components and mass percentages of ferroboron are: B: 19.0-21.0%, and the rest are iron and inevitable impurities. The amount of ferroboron added is 0.15-0.2% of the total mass of the molten iron.

6. The method for preparing a high chromium cast iron arc liner according to claim 1, characterized in that: In step S3, the specific process of heating the casting is as follows: the arc liner casting is placed in a heating furnace at room temperature, heated to 650-700°C at a heating rate of 60-80°C / hour, and kept warm for 2-3 hours; then heated to 980-1020°C at a heating rate of 120-150°C / hour, and kept warm for 2-4 hours.

7. The method for preparing a high chromium cast iron arc liner according to claim 6, characterized in that: In step S3, the cooling water flow rate introduced into the processing mold is calibrated to be 30-50 kg / min.

8. The method for preparing a high chromium cast iron arc liner according to claim 7, characterized in that: The fixed mold (100) and the movable mold (200) are respectively mounted on a workbench via a fixed mold flange (130) and a movable mold flange (230).

9. The method for preparing a high chromium cast iron arc liner according to claim 8, characterized in that: The workbench is an oil press, which is in transmission connection with the movable die (200) and drives the movable die (200) to correct the curvature of the wear-resistant arc liner.

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