Wear-resistant and heat-resistant single-tooth roller grate plate as well as preparation method and application thereof

Abstract

The invention relates to a wear-resistant and heat-resistant single-tooth roller grate plate as well as a preparation method and application thereof, and relates to the technical field of steel smelting. The wear-resistant and heat-resistant single-tooth roller grate plate comprises a grate plate main body, wherein the grate plate main body comprises a grate plate framework and an alloy protective layer poured on the grate plate framework; and the alloy protection layer comprises the following components in percentage by mass: 1.7%-1.9% of C, 0.8%-1.5% of Si, 1.5%-3.0% of Mn, 0.02%-0.35% of P, 0.02%-0.035% of S, 27%-29% of Cr, 1.5%-2.5% of Mo, 1.6%-2.5% of Ni, 0.3%-1.0% of W, 0.1%-0.2% of V, 0.2%-0.5% of Ti, 0.01%-0.02% of Re and the balance of Fe and inevitable impurities. The single-tooth roller grate plate provided by the invention has good wear resistance and heat resistance.

Description

Technical Field

[0001] The invention relates to the technical field of steel smelting, and in particular to a wear-resistant and heat-resistant single-tooth roller grate plate and a preparation method and application thereof. Background Art

[0002] The single-tooth roller crusher is an important equipment in the sintering machine. Its main function is to crush the high-temperature sintering material at the tail of the machine into a certain size to meet the requirements of the size of the iron-making blast furnace. The single-tooth roller crusher is mainly composed of a single-tooth roller and a grate plate. It needs to have wear resistance in a high-temperature environment of about 800 degrees. Therefore, its wear resistance and heat resistance directly affect the quality and output of the sintering material. At present, the domestic production of single-tooth roller grate plates is mainly made of steel plates of a certain thickness to form the grate plate body, and the upper part of the body is installed with a U-shaped or T-shaped alloy protective layer in the form of bolts or slots. Although the grate plate of this structure is convenient for replacing the upper alloy layer, due to the gap between the grate plate and the alloy layer, the scraping and extrusion wear formed between the roller teeth, the grate plate and the high-temperature sintering material during the operation of the single-tooth roller crusher causes the alloy layer to produce relative displacement on the upper part of the grate plate, which is easy to cause the grate plate to fail prematurely as a whole. Some grate plates even have to be replaced after one month of being online, which seriously affects the quality and output of the sintering process. Summary of the invention

[0003] In order to solve the problems of poor wear resistance and heat resistance and short service life of grate plates in the prior art, the present invention provides a wear-resistant and heat-resistant single-tooth roller grate plate and a preparation method and application thereof.

[0004] The present invention provides a wear-resistant and heat-resistant single-tooth roller grate plate, which adopts the following technical solution:

[0005] A wear-resistant and heat-resistant single-tooth roller grate plate comprises a grate plate body, wherein the grate plate body comprises a grate plate frame and an alloy protective layer cast on the grate plate frame; The alloy protective layer includes the following components in mass percentage: C 1.7%-1.9%, Si 0.8%-1.5%, Mn1.5%-3.0%, P 0.02%-0.35%, S 0.02%-0.035%, Cr 27%-29%, Mo 1.5%-2.5%, Ni1.6%-2.5%, W 0.3%-1.0%, V 0.1%-0.2%, Ti 0.2%-0.5%, Re 0.01%-0.02% and the remainder of Fe and unavoidable impurities.

[0006] The present invention adjusts the chemical composition of the alloy protective layer so that the cast alloy protective layer has good oxidation resistance and suitable hardness, effectively improves the wear and heat resistance of the grate plate, and makes its service life reach 14-16 months, wherein the carbon content in the alloy protective layer determines the number of carbides, the chromium content determines the type of carbides, nickel helps austenite supercooling, and the ability of molybdenum, tungsten, vanadium, and titanium to generate carbides is greater than that of manganese and chromium, forming carbides that are better than those formed by chromium. Such a limitation enables the alloy protective layer to have high microhardness and wear resistance at high temperatures. At the same time, the present invention casts the alloy protective layer on the grate plate skeleton so that the alloy protective layer and the grate plate skeleton are tightly connected together, avoiding excessive wear of the grate plate due to relative displacement of the alloy protective layer on the grate plate, improving the wear resistance of the grate plate, and thus extending the service life of the grate plate.

[0007] Optionally, the grate plate main body also includes a rib plate arranged on the grate plate frame, the lower end of the rib plate is fixedly connected to the grate plate frame, the upper end of the rib plate is provided with a dovetail groove, and a circular through hole is provided on the middle area of ​​the rib plate, and the alloy protective layer covers the outside of the rib plate and fills the dovetail groove and the circular through hole.

[0008] The present invention utilizes a rib plate provided with a circular through hole and a dovetail groove, so that the grate plate body and the alloy protective layer are tightly connected through the circular through hole and the dovetail groove, further improving the tightness of the combination of the grate plate body and the alloy protective layer, and solving the problem of aggravated wear between the grate plate body and the alloy layer due to the existence of a gap.

[0009] Optionally, the rib plate includes a left rib plate, a right rib plate and a middle partition plate, the left side wall of the left rib plate is connected to the inner side of the grate plate frame, the right side wall of the right rib plate is connected to the inner side of the grate plate frame, and the middle partition plate is arranged between the left rib plate and the right rib plate.

[0010] The present invention improves the force balance of the working area of ​​the alloy protective layer of the grate plate by arranging two rib plates, effectively prolonging the service life of the grate plate, and at the same time, the present invention avoids the collapse of the alloy protective layer during the casting process by arranging a middle partition between the two rib plates. In addition, the middle partition is located in the non-working area of ​​the grate plate, and the middle partition can be made of conventional metal materials to reduce the cost of the single-tooth roller grate plate.

[0011] In the present invention, dovetail grooves are provided at the upper ends of the left end rib plate and the right end rib plate, circular through holes are provided on the middle areas of the left end rib plate and the right end rib plate, and the alloy protective layer covers the outside of the left end rib plate, the right end rib plate and the middle partition plate and fills the dovetail grooves and the circular through holes.

[0012] The present invention also provides a method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate described in the above technical solution, which adopts the following technical solution:

[0013] A method for preparing a wear-resistant and heat-resistant single-tooth roller grate plate comprises the following steps: Step 1: Melting the materials of each layer of the grate plate according to the required composition to obtain the grate plate main body molten metal and alloy protective layer molten metal of the designed proportion; Step 2: pouring the grate plate main body molten metal into the grate plate main body sand mold cavity, cleaning and performing a first heat treatment after the grate plate main body molten metal solidifies to obtain the grate plate main body, and pre-embedding the grate plate main body into the alloy protective layer sand mold cavity; Step three: pouring the alloy protective layer metal liquid into the alloy protective layer sand mold cavity, and after the alloy protective layer metal liquid solidifies, performing a second heat treatment and cleaning in sequence to obtain a composite wear-resistant and heat-resistant single-tooth roller grate plate.

[0014] The invention pours the alloy protective layer on the grate plate frame so that the alloy protective layer and the grate plate frame are tightly connected together, avoiding excessive wear of the grate plate due to relative displacement of the alloy protective layer on the grate plate, improving the wear resistance of the grate plate, and further extending the service life of the grate plate.

[0015] Optionally, the method for preparing the grate plate main body sand mold comprises the following steps: Placing the grate plate main body model in a first sand box, and filling the first sand box with resin sand until the resin sand hardens to form a first primary sand mold, the first primary sand mold can be opened to take out the grate plate main body model, and the grate plate main body model is consistent with the grate plate main body shape; Opening the first primary sand mold, taking out the grate plate main body model, and obtaining a grate plate main body sand mold, wherein a grate plate main body sand mold cavity corresponding to the grate plate main body is formed in the grate plate main body sand mold; The method for preparing the alloy protective layer sand mold comprises the following steps: Place the grate plate body in a second sand box, place the alloy protective layer model on the grate plate body, and fill the second sand box with resin sand until the resin sand hardens to form a second primary sand mold. The second primary sand mold can be opened to take out the alloy protective layer model, and the alloy protective layer model is consistent with the shape of the alloy protective layer; open the second primary sand mold, take out the alloy protective layer model, and obtain the alloy protective layer sand mold, and an alloy protective layer sand mold cavity corresponding to the alloy protective layer is formed in the alloy protective layer sand mold.

[0016] Optionally, a sand mold structure corresponding to the dovetail groove on the upper end of the rib plate is provided in the second primary sand mold.

[0017] The present invention utilizes a grate plate main body model, an alloy protective layer model and hard sand to prepare a grate plate main body sand mold and an alloy protective layer sand mold, thereby ensuring that the prepared grate plate main body and alloy protective layer have shapes that meet requirements.

[0018] Optionally, a direct chill is also provided in the second primary sand mold.

[0019] Optionally, the direct chill is arranged in a sand mold structure corresponding to the dovetail groove on the upper end of the rib plate. The present invention provides the direct chill so that the direct chill and the grate plate body can play a chilling role, ensuring that the alloy protective cap obtains an austenite + carbide structure in the cast state, thereby improving the wear resistance and heat resistance of the grate plate body.

[0020] Optionally, the temperature for pouring the molten metal of the grate plate body is 1530°C-1550°C, and the temperature for pouring the molten metal of the alloy protective layer is 1480°C-1500°C.

[0021] The present invention can effectively improve the wear resistance and heat resistance of the grate plate main body by limiting the metal liquid pouring temperature of the grate plate main body and the alloy protective layer.

[0022] Optionally, the temperature of the first heat treatment is 800°C-900°C, and the insulation time is 3h-5h, and the temperature of the second heat treatment is 200°C-300°C, and the insulation time is 5h-7h.

[0023] The present invention limits the temperature and time of the first heat treatment and the second heat treatment to ensure that the alloy protective layer obtains austenite and carbide, thereby further improving the wear resistance and heat resistance of the alloy protective layer.

[0024] Optionally, in step three, a modifier is added to the molten alloy protective layer metal before pouring the molten alloy protective layer metal into the alloy protective layer sand mold cavity; the amount of the modifier added is 0.3-0.5% of the weight of the molten alloy protective layer metal, and the modifier is a mixture of ferrovanadium alloy and rare earth silicon with a particle size of 2mm-5mm, and the mass ratio of the ferrovanadium alloy to the rare earth silicon is 1:0.75-1.25.

[0025] The invention further improves the wear resistance and heat resistance of the grate plate main body through modification treatment.

[0026] The present invention also provides a single-tooth roller crusher, comprising the wear-resistant and heat-resistant single-tooth roller grate plate described in the above scheme.

[0027] The wear-resistant and heat-resistant single-tooth roller grate plate provided by the aforementioned scheme of the present invention can effectively improve the wear-resistant and heat-resistant performance of the single-tooth roller crusher, thereby extending its service life.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The present invention adjusts the chemical composition of the alloy protective layer so that the cast alloy protective layer has good oxidation resistance and appropriate hardness, effectively improves the wear resistance and heat resistance of the grate plate, and makes the service life of the single-tooth roller grate plate reach 14-16 months, wherein the carbon content determines the amount of carbides, the chromium content determines the type of carbides, nickel helps austenite supercooling, and the ability of molybdenum, tungsten, vanadium, and titanium to generate carbides is greater than that of manganese and chromium, forming carbides that are better than those formed by chromium, which have high microhardness and wear resistance at high temperatures. At the same time, the present invention casts the alloy protective layer on the grate plate skeleton so that the alloy protective layer and the grate plate skeleton are tightly connected together, effectively improving the wear resistance of the grate plate, and avoiding excessive wear of the grate plate due to relative displacement of the alloy protective layer on the grate plate; 2. The present invention limits the specific pouring process to prevent deformation during pouring and use, while effectively improving the bonding stability between the grate plate body and the alloy protective layer, further improving the wear and heat resistance of the grate plate and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a front view of the wear-resistant and heat-resistant single-tooth roller grate plate provided by the present invention;

[0030] Figure 2 yes Figure 1 Left view of

[0031] Figure 3 yes Figure 2 The cross-section along the AA direction;

[0032] Figure 4 is a metallographic diagram of the alloy protective layer of the present invention;

[0033] Explanation of the accompanying reference numerals: 1. grate plate body; 2. alloy protective layer; 3. rib plate; 4. middle partition plate. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The following is combined with Figure 1-4 The present invention is described in further detail.

[0036] The present invention provides a wear-resistant and heat-resistant single-tooth roller grate plate, comprising a grate plate main body, wherein the grate plate main body comprises a grate plate frame 1 and an alloy protective layer 2 cast on the grate plate frame 1; The alloy protective layer 2 includes the following components in mass percentage: C 1.7%-1.9%, Si 0.8%-1.5%, Mn 1.5%-3.0%, P 0.02%-0.35%, S 0.02%-0.035%, Cr 27%-29%, Mo 1.5%-2.5%, Ni 1.6%-2.5%, W 0.3%-1.0%, V 0.1%-0.2%, Ti 0.2%-0.5%, Re 0.01%-0.02% and the remainder of Fe and inevitable impurities.

[0037] The present invention adjusts the chemical composition of the alloy protective layer so that the cast alloy protective layer has good oxidation resistance and suitable hardness, effectively improves the wear and heat resistance of the grate plate, and makes its service life reach 14-16 months, wherein the carbon content in the alloy protective layer determines the number of carbides, the chromium content determines the type of carbides, nickel helps austenite supercooling, and the ability of molybdenum, tungsten, vanadium, and titanium to generate carbides is greater than that of manganese and chromium, forming carbides that are better than those formed by chromium. Such a limitation enables the alloy protective layer to have high microhardness and wear resistance at high temperatures. At the same time, the present invention casts the alloy protective layer on the grate plate skeleton so that the alloy protective layer and the grate plate skeleton are tightly connected together, avoiding excessive wear of the grate plate due to relative displacement of the alloy protective layer on the grate plate, improving the wear resistance of the grate plate, and thus extending the service life of the grate plate.

[0038] Optionally, the grate plate body also includes a rib plate 3 arranged on the grate plate frame 1, the lower end of the rib plate 3 is fixedly connected to the grate plate frame 1, the upper end of the rib plate 3 is provided with a dovetail groove, and a circular through hole is provided on the middle area of ​​the rib plate 3, and the alloy protective layer 2 covers the outside of the rib plate 1 and fills the dovetail groove and the circular through hole.

[0039] The present invention utilizes a rib plate provided with a circular through hole and a dovetail groove, so that the grate plate body and the alloy protective layer are tightly connected through the circular through hole and the dovetail groove, further improving the tightness of the combination of the grate plate body and the alloy protective layer, and solving the problem of aggravated wear between the grate plate body and the alloy layer due to the existence of a gap.

[0040] Optionally, the rib plate includes a left end rib plate, a right end rib plate and a middle partition plate, the left side wall of the left end rib plate is connected to the inner side of the grate plate frame, the right side wall of the right end rib plate is connected to the inner side of the grate plate frame, and the middle partition plate is arranged between the left end rib plate and the right end rib plate.

[0041] The present invention improves the force balance of the working area of ​​the alloy protective layer of the grate plate by arranging two rib plates, effectively prolonging the service life of the grate plate, and at the same time, the present invention avoids the collapse of the alloy protective layer during the casting process by arranging a middle partition between the two rib plates. In addition, the middle partition is located in the non-working area of ​​the grate plate, and the middle partition can be made of conventional metal materials to reduce the cost of the single-tooth roller grate plate.

[0042] In the present invention, dovetail grooves are provided at the upper ends of the left end rib plate and the right end rib plate, circular through holes are provided on the middle areas of the left end rib plate and the right end rib plate, and the alloy protective layer covers the outside of the left end rib plate, the right end rib plate and the middle partition plate and fills the dovetail grooves and the circular through holes.

[0043] The present invention also provides a method for preparing a wear-resistant and heat-resistant single-tooth roller grate plate, and the following is a specific embodiment:

[0044] Embodiment 1:

[0045] A method for preparing a wear-resistant and heat-resistant single-tooth roller grate plate comprises the following steps: Step 1: The grate plate body is made of ZG340-640, and the elements of the alloy protective layer are: C 1.76%, Si 0.9%, Mn 3.0%, P 0.02%, S 0.03%, Cr 28%, Mo 1.86%, Ni 1.63%, W 0.87%, V 0.21%, Ti 0.37%, Re 0.016% and the remaining Fe and inevitable impurities. The grate plate body metal liquid and the alloy protective layer metal liquid are obtained according to the composition requirements of each layer of the grate plate. Step 2: pour the grate plate main body metal liquid into the grate plate main body sand mold cavity, the pouring temperature is 1536℃, wait for the grate plate main body metal liquid to solidify, obtain the grate plate main body with grate plate skeleton, put the grate plate main body into the heat treatment furnace and heat it up to 860℃ at a heating rate of 60℃ / h, keep it warm for 4h, take it out of the furnace and clean it to obtain the grate plate main body without internal stress, then embed it into the alloy protective layer sand mold cavity, and set the top gate funnel; The method for preparing the grate plate main body sand mold comprises the following steps: placing a grate plate main body model consistent with the grate plate main body shape in a first sand box, and filling the first sand box with resin sand until the resin sand hardens to form a first primary sand mold that can be opened to take out the grate plate main body model; opening the first primary sand mold, taking out the grate plate main body model, and obtaining the grate plate main body sand mold, wherein a grate plate main body sand mold cavity corresponding to the grate plate main body shape is formed in the grate plate main body sand mold; Step 3: pouring the alloy protective layer metal liquid into the alloy protective layer sand mold cavity at a pouring temperature of 1490°C. After the alloy protective layer metal liquid solidifies, it is subjected to a modification treatment using 2-4 mm ferrovanadium and rare earth silicon, and then heated at a rate of 40°C / h to 260°C for 6 hours, and then cooled to 100°C with the furnace. After being taken out of the furnace and cleaned, a composite wear-resistant and heat-resistant single-tooth roller grate plate with internal stress removed is obtained; Among them, the preparation method of the alloy protective layer sand mold includes the following steps: placing a grate plate body consistent with the shape of the alloy protective layer in a second sand box, placing the alloy protective layer model on the grate plate body, and filling the second sand box with resin sand until the resin sand hardens to form a second primary sand mold that can be opened to remove the alloy protective layer model; opening the second primary sand mold, taking out the alloy protective layer model, obtaining the alloy protective layer sand mold, and forming an alloy protective layer sand mold cavity corresponding to the shape of the alloy protective layer in the alloy protective layer sand mold.

[0046] Embodiment 2:

[0047] A method for preparing a wear-resistant and heat-resistant single-tooth roller grate plate comprises the following steps: Step 1: The grate plate body is made of ZG340-640, and the elements of the alloy protective layer are C1.55%, Si 1.2%, Mn 3.2%, P 0.025%, S 0.033%, Cr 28.4%, Mo 1.91%, Ni 1.86%, W 0.58%, V0.29%, Ti 0.41%, Re 0.015% and the balance of Fe and inevitable impurities. The materials are smelted according to the required components of each layer of the grate plate to obtain the grate plate body molten metal and the alloy protective layer molten metal; Step 2: pour the grate plate main body metal liquid into the grate plate main body sand mold cavity, the pouring temperature is 1546℃, wait for the grate plate main body metal liquid to solidify, and obtain the grate plate main body provided with a grate plate skeleton, the grate plate skeleton is fixedly connected with a rib plate, the upper end of the rib plate is provided with 10 dovetail grooves, and the middle area of ​​the rib plate is provided with 8 circular through holes, the grate plate main body is placed in a heat treatment furnace and heated to 860℃ at a heating rate of 60℃ / h, and after keeping warm for 4h, it is taken out of the furnace and cleaned to obtain a grate plate main body without internal stress, and then pre-buried in the alloy protective layer sand mold cavity, and the top gate funnel is set; The preparation method of the grate plate main body sand mold comprises the following steps: placing a grate plate main body model consistent with the grate plate main body shape in a first sand box, and filling the first sand box with resin sand until the resin sand hardens to form a first primary sand mold that can be opened to take out the grate plate main body model; opening the first primary sand mold, taking out the grate plate main body model, and obtaining the grate plate main body sand mold, wherein a grate plate main body sand mold cavity corresponding to the grate plate main body shape is formed in the grate plate main body sand mold; Step 3: pouring the alloy protective layer metal liquid into the alloy protective layer sand mold cavity at a pouring temperature of 1483°C. After the alloy protective layer metal liquid solidifies, it is subjected to a modification treatment using 3-5 mm ferrovanadium and rare earth silicon, and then heated at a rate of 40°C / h to 260°C for 6 hours, and then cooled to 100°C with the furnace. After being taken out of the furnace and cleaned, a composite wear-resistant and heat-resistant single-tooth roller grate plate is obtained; Among them, the preparation method of the alloy protective layer sand mold includes the following steps: placing a grate plate body consistent with the shape of the alloy protective layer in a second sand box, placing the alloy protective layer model on the grate plate body, and filling the second sand box with resin sand until the resin sand hardens to form a second primary sand mold that can be opened to remove the alloy protective layer model; opening the second primary sand mold, taking out the alloy protective layer model, obtaining the alloy protective layer sand mold, and forming an alloy protective layer sand mold cavity corresponding to the shape of the alloy protective layer in the alloy protective layer sand mold.

[0048] Embodiment 3:

[0049] A method for preparing a wear-resistant and heat-resistant single-tooth roller grate plate comprises the following steps: Step 1: The grate plate body is made of ZG340-640, and the alloy protective layer is made of: C 2.07%, Si 1.45%, Mn%, P 0.025%, S 0.04%, Cr 27.2%, Mo 1.71%, Ni 2.15%, W 0.48%, V 0.13%, Ti0.38%, Re 0.016% and the balance Fe alloy. Melting is performed according to the composition requirements of each layer of the grate plate material to obtain the grate plate body molten metal and the alloy protective layer molten metal; Step 2: pour the grate plate main body molten metal into the grate plate main body sand mold cavity at a pouring temperature of 1538°C, wait for the grate plate main body molten metal to solidify, and obtain a grate plate main body provided with a grate plate frame, on which a left end rib plate and a right end rib plate are fixedly connected, the left side wall of the left end rib plate is connected to the inner side of the grate plate frame, the right side wall of the right end rib plate is connected to the inner side of the rib plate frame, and the middle partition is provided between the left end rib plate and the right end rib plate. The upper ends of the left and right ribs are each provided with 4 circular through holes, and the middle areas of the left and right ribs are each provided with 5 dovetail grooves. The main body of the grate plate after grinding and cleaning is put into the heat treatment furnace and heated to 860°C at a heating rate of 60°C / h. After being kept warm for 4 hours, it is taken out of the furnace and air-cooled to obtain a main body of the grate plate without internal stress. Then, it is pre-embedded in the sand mold of the alloy layer during the molding process of the alloy layer, and the top gate funnel is set; The preparation method of the grate plate main body sand mold comprises the following steps: placing a grate plate main body model consistent with the grate plate main body shape in a first sand box, and filling the first sand box with resin sand until the resin sand hardens to form a first primary sand mold that can be opened to take out the grate plate main body model; opening the first primary sand mold, taking out the grate plate main body model, and obtaining the grate plate main body sand mold, wherein a grate plate main body sand mold cavity corresponding to the grate plate main body shape is formed in the grate plate main body sand mold; Step 3: Pour the alloy protective layer metal liquid into the alloy protective layer sand mold cavity at a pouring temperature of 1491°C. After the alloy protective layer metal liquid solidifies, it is subjected to a modification treatment using 3-5 mm ferrovanadium and rare earth silicon, and then heated at a rate of 40°C / h to 260°C for 6 hours, and then cooled to 100°C with the furnace. After being taken out of the furnace and cleaned, a composite wear-resistant and heat-resistant single-tooth roller grate plate is obtained. The front view of the wear-resistant and heat-resistant single-tooth roller grate plate is as follows: Figure 1 As shown, Figure 2 for Figure 1 The left view of Figure 3 yes Figure 2 The cross-section along the AA direction; Among them, the preparation method of the alloy protective layer sand mold includes the following steps: placing a grate plate body consistent with the shape of the alloy protective layer in a second sand box, placing the alloy protective layer model on the grate plate body, and filling the second sand box with resin sand until the resin sand hardens to form a second primary sand mold that can be opened to remove the alloy protective layer model; opening the second primary sand mold, taking out the alloy protective layer model, obtaining the alloy protective layer sand mold, and forming an alloy protective layer sand mold cavity corresponding to the shape of the alloy protective layer in the alloy protective layer sand mold.

[0050] The alloy protective layer in Example 1 was subjected to metallographic examination, and the results are as follows: Figure 4 As shown, the metallographic structure in the main body of the alloy protective layer is alloy carbide and austenite, wherein the carbide content accounts for 34%. The austenite in the alloy protective layer provided by the present invention rarely undergoes phase change under alternating changes between room temperature and high temperature of 800-900°C, and can play a good role in fixing and supporting carbides. The alloy carbides have high microhardness and stability, and can play a role in resisting wear.

[0051] The hardness of the alloy protective layer body in Example 1 was tested, and the hardness of the alloy protective layer body was HRC48-51, and its service life could reach 15 months.

[0052] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A wear-resistant and heat-resistant single-tooth roller grate plate, comprising a grate plate body, wherein the grate plate body comprises a grate plate frame, characterized in that: Also includes an alloy protective layer cast on the grate plate skeleton; The alloy protective layer includes the following components in mass percentage: C 1.7%-1.9%, Si 0.8%-1.5%, Mn1.5%-3.0%, P 0.02%-0.35%, S 0.02%-0.035%, Cr 27%-29%, Mo 1.5%-2.5%, Ni1.6%-2.5%, W 0.3%-1.0%, V 0.1%-0.2%, Ti 0.2%-0.5%, Re 0.01%-0.02% and the remainder of Fe and unavoidable impurities.

2. The wear-resistant and heat-resistant single-tooth roller grate plate according to claim 1, characterized in that: The grate plate body also includes a rib plate arranged on the grate plate frame, the lower end of the rib plate is fixedly connected to the grate plate frame, the upper end of the rib plate is provided with a dovetail groove, and the middle area of ​​the rib plate is provided with a circular through hole, and the alloy protective layer covers the outside of the rib plate and fills the dovetail groove and the circular through hole.

3. The wear-resistant and heat-resistant single-tooth roller grate plate according to claim 2, characterized in that: The rib plate includes a left end rib plate, a right end rib plate and a middle partition plate. The left side wall of the left end rib plate is connected to the inner side of the grate plate frame, the right side wall of the right end rib plate is connected to the inner side of the grate plate frame, and the middle partition plate is arranged between the left end rib plate and the right end rib plate.

4. The method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Melting the materials of each layer of the grate plate according to the required composition to obtain the grate plate main body molten metal and alloy protective layer molten metal of the designed proportion; Step 2: pouring the grate plate main body molten metal into the grate plate main body sand mold cavity, cleaning and performing a first heat treatment after the grate plate main body molten metal solidifies to obtain the grate plate main body, and pre-embedding the grate plate main body into the alloy protective layer sand mold cavity; Step three: pouring the alloy protective layer metal liquid into the alloy protective layer sand mold cavity, and after the alloy protective layer metal liquid solidifies, performing a second heat treatment and cleaning in sequence to obtain a composite wear-resistant and heat-resistant single-tooth roller grate plate.

5. The method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate according to claim 4, characterized in that: The method for preparing the grate plate main body sand mold comprises the following steps: Placing the grate plate main body model in a first sand box, and filling the first sand box with resin sand until the resin sand hardens to form a first primary sand mold, the first primary sand mold can be opened to take out the grate plate main body model, and the grate plate main body model is consistent with the grate plate main body shape; Opening the first primary sand mold, taking out the grate plate main body model, and obtaining a grate plate main body sand mold, wherein a grate plate main body sand mold cavity corresponding to the grate plate main body is formed in the grate plate main body sand mold; The method for preparing the alloy protective layer sand mold comprises the following steps: Place the grate plate body in a second sand box, place the alloy protective layer model on the grate plate body, and fill the second sand box with resin sand until the resin sand hardens to form a second primary sand mold. The second primary sand mold can be opened to take out the alloy protective layer model, and the alloy protective layer model is consistent with the shape of the alloy protective layer; open the second primary sand mold, take out the alloy protective layer model, and obtain the alloy protective layer sand mold, and an alloy protective layer sand mold cavity corresponding to the alloy protective layer is formed in the alloy protective layer sand mold.

6. The method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate according to claim 5, characterized in that: The second primary sand mold is also provided with direct chill.

7. The method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate according to claim 4, characterized in that: The temperature for pouring the molten metal of the grate plate body is 1530°C-1550°C, and the temperature for pouring the molten metal of the alloy protection layer is 1480°C-1500°C.

8. The method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate according to claim 4, characterized in that: The temperature of the first heat treatment is 800°C-900°C, and the insulation time is 3h-5h. The temperature of the second heat treatment is 200°C-300°C, and the insulation time is 5h-7h.

9. The method for preparing the wear-resistant and heat-resistant single-tooth roller grate plate according to claim 4, characterized in that: In the step three, a modifier is added to the alloy protective layer metal liquid before pouring the alloy protective layer metal liquid into the alloy protective layer sand mold cavity; the amount of the modifier added is 0.3-0.5% of the weight of the alloy protective layer metal liquid, and the modifier is a mixture of vanadium iron alloy and rare earth silicon with a particle size of 2mm-5mm, and the mass ratio of the vanadium iron alloy to the rare earth silicon is 1:0.75-1.

25.

10. A single tooth roller crusher, characterized in that: It comprises the wear-resistant and heat-resistant single-tooth roller grate plate described in any one of claims 1 to 3 or the wear-resistant and heat-resistant single-tooth roller grate plate prepared by the preparation method described in any one of claims 4 to 9.

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