A wear-resistant crusher hammer head and a preparation method thereof

Abstract

The application discloses a wear-resistant crusher hammer head and a preparation method thereof, which comprises the following components in percentage by weight: C 1.2-1.8%, W 0.5-0.8%, Cr+V 25-30%, Ni+Mo 0.5-5%, Cu 0.5-1.5%, Mn 2-3%, Pb 0.2-0.35%; the weight ratio of Cr+V to Ni+Mo is 10:1 to 20:1. Through the design of the total amount of Cr+V and the total amount of Ni+Mo and the proportioning design of the two, the application realizes the overall adjustment and control of the proportion of strengthening and toughening, and through the design of three continuous heat treatment processes of quenching, tempering and normalizing in the forming process, the microstructure of the castings is fully transformed into high-hardness martensite microstructure, so that the prepared crusher hammer head is endowed with higher mechanical strength and appropriate toughness, the strength is ensured and the impact cracking is avoided, thereby effectively improving the wear resistance and impact resistance of the hammer head and prolonging the service life of the hammer head.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crushers, in particular to a wear-resistant crusher hammer head and a preparation method thereof. BACKGROUND

[0002] A crusher is a kind of machine that uses high-speed rotating hammer heads to impact materials so as to break and crush the materials. The hammer head is the main component of the crusher for breaking and crushing materials, and has the characteristics of simple structure and large acting surface.

[0003] During the working process of the crusher hammer head, the hammer head directly contacts with the materials to be crushed at a high speed to achieve the optimal crushing effect. However, in this process, the hammer head is subjected to a large counter-impact force and friction force from the materials, and thus the hammer head is prone to damage such as wear and tear and has a short service life.

[0004] Chinese patent CN 109433335 A discloses a kind of high-strength high-wear-resistant crusher hammer head, which mainly protects the base body by bonding a functional layer on the surface of the base body on the basis of improving the formula of the base body to improve the service life of the hammer head.

[0005] However, the present inventors found at least the following technical problems in the process of implementing the technical scheme of the embodiments of the present application: due to the protection of the functional layer, the base body is not directly in contact with the materials to be crushed, which can prevent the base body from being worn to a certain extent, but the impact energy between the base body and the materials to be crushed can still cause cracks in the base body. In addition, the functional layer and the base body are bonded and fixed, and the bonding layer is easy to fall off during repeated impact, which cannot fundamentally improve the impact resistance and wear resistance of the base body. SUMMARY

[0006] The present application provides a kind of wear-resistant crusher hammer head and a preparation method thereof, which can solve the defects of insufficient wear resistance and easy to produce impact cracks of the hammer head in the prior art.

[0007] To solve the above technical problems, the present application provides a kind of wear-resistant crusher hammer head, which comprises the following components by weight percentage:

[0008] C 1.2-1.8%, W 0.5-0.8%, Cr+V 25-30%, Ni+Mo 0.5-5%, Cu 0.5-1.5%, Mn 2-3%, Pb 0.2-0.35%, impurities less than 0.1%, and the rest is Fe; wherein the weight ratio of Cr+V to Ni+Mo is 10:1 to 20:1.

[0009] In a preferred embodiment of the present application, the weight ratio of Cr to V in Cr+V is 1:1 to 3:1.

[0010] In a preferred embodiment of the present application, the weight ratio of Ni to Mo in the Ni+Mo is 1:1 to 1:3.

[0011] To solve the above technical problems, the present application provides a preparation method of a wear-resistant crusher hammer head, comprising the following steps:

[0012] (1) Feeding and melting: calculate the required iron raw materials according to the formula, and add them to the smelting furnace to melt into molten iron. When the temperature of the molten iron stabilizes at 1550-1600℃, deoxidize it;

[0013] (2) Casting: put the modified modifier into the ladle bottom, then pour the deoxidized molten iron in step (1) into the ingot mold, and after heat preservation and solidification, cool it to room temperature to form a cast piece;

[0014] (3) Heat treatment: polish the corners of the cast piece obtained in step (2), and then sequentially perform quenching treatment, tempering treatment and normalizing treatment;

[0015] (4) Hot rolling: after the heat treatment of step (3) is completed, the cast piece is sawn and then hot rolled to the required hammer head shape. After hot rolling, it is naturally cooled to room temperature;

[0016] (5) Annealing treatment: place the hammer head after hot rolling in step (4) in an annealing furnace for annealing treatment to obtain the wear-resistant crusher hammer head.

[0017] In a preferred embodiment of the present application, in step (3), the process conditions of the quenching treatment are: quenching temperature 1150-1250℃, holding time 2-3.5h, then furnace cooling to 800-900℃, oil cooling to 200-300℃ after discharging, and finally air cooling to room temperature.

[0018] In a preferred embodiment of the present application, in step (3), the process conditions of the tempering treatment are: tempering temperature 450-550℃, holding time 4.5-5h, and air cooling to room temperature after taking out.

[0019] In a preferred embodiment of the present application, in step (3), the process conditions of the normalizing treatment are: normalizing temperature 850-900℃, time 2-3h, and then air cooling to room temperature after discharging.

[0020] In a preferred embodiment of the present application, in step (4), the process conditions of the hot rolling treatment are: first heated to 1250℃±30℃ for primary hot rolling, then cooled to 1100℃±30℃ for secondary hot rolling, and then cooled to 950℃±30℃ for tertiary hot rolling. After hot rolling, water cooling to room temperature.

[0021] In a preferred embodiment of the present application, the reduction ratio of the first hot rolling is 25-30%, the reduction ratio of the second hot rolling is 10-15%, and the reduction ratio of the third hot rolling is 5-10%.

[0022] In a preferred embodiment of the present application, in step (5), the process conditions of the annealing treatment are as follows: annealing temperature 500-550 DEG C, holding for 3-4 hours, then furnace cooling to 200 DEG C, and natural cooling to room temperature after furnace discharge.

[0023] The present application has the advantages that: the wear-resistant crusher hammer head and the preparation method thereof, through the design of the total amount of the element Cr+V mainly playing a reinforcing role and the total amount of the element Ni+Mo mainly playing a toughening role and the matching design of the two, the proportion of the reinforcement and the toughening is overall adjusted and controlled, and through the design of the three continuous heat treatment processes of quenching, tempering and normalizing in the forming process, the microstructure of the castings is fully changed into high-hardness martensite, so that the prepared crusher hammer head has high mechanical strength and appropriate toughness, which ensures the strength and avoids impact cracking, thereby effectively improving the wear resistance and impact resistance of the hammer head and prolonging the service life. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a process flow diagram of the preparation method of the wear-resistant crusher hammer head. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and definitely defined.

[0026] Please refer to Figure 1 The embodiments of the present application include:

[0027] Embodiment 1

[0028] A wear-resistant crusher hammer head comprises the following components in weight percentage:

[0029] C 1.2%, W 0.5%, Cr+V 25%, Ni+Mo 2.5%, Cu 0.5%, Mn 2%, Pb 0.2%, impurities less than 0.1%, and the rest is Fe; the weight ratio of the Cr+V to the Ni+Mo is 10:1. The Cr and V elements play a role in increasing the strength and improving the wear resistance; the Ni and Mo elements play a role in impact toughness, preventing problems such as brittle fracture and cracking during use; through the design of the amount ratio of the Cr+V to the Ni+Mo, the strength and toughness of the crusher hammer head as a whole are comprehensively adjusted to ensure that it has sufficient strength, wear resistance, and meets certain toughness, and does not have defects such as brittle cracking.

[0030] Specifically, in the Cr+V, the weight ratio of Cr to V is 2:1.

[0031] In the Ni+Mo, the weight ratio of Ni to Mo is 1:2.

[0032] The preparation method of the wear-resistant crusher hammer head includes the following steps:

[0033] (1) Feeding and melting: the required iron raw materials are calculated according to the above formula, and then all the iron raw materials are added to a smelting furnace to melt into molten iron. When the temperature of the molten iron is stabilized at 1600℃, pure aluminum is added for deoxidization to obtain refined molten iron;

[0034] (2) Casting: a modified modifier accounting for 3.3% of the mass of the molten iron is placed at the bottom of a ladle, and the modified modifier is a rare earth modifier with a brand of FeSiMg8RE7; then the refined and deoxidized molten iron in step (1) is poured into a ingot mold, and after being kept at 1480-1500℃ for 3h, it is cooled to room temperature to obtain a cast piece; the addition of the modified modifier is beneficial to improving the toughness of the cast piece after forming;

[0035] (3) Heat treatment: after the cast piece obtained in step (2) is taken out, the riser position and the corner position are polished, and then it is first added to a quenching furnace with a temperature of 1150℃ and kept at a constant temperature for 3h, and then cooled to 800℃ in the furnace, and then oil-cooled to 200℃ after being taken out of the furnace, and finally air-cooled to room temperature. Through quenching treatment, the microstructure in the cast piece is martensitized to obtain high-hardness martensitic structure.

[0036] After quenching treatment, the obtained cast piece is placed in a tempering furnace with a temperature of 450℃ and kept at a constant temperature for 4.5h, and then taken out and air-cooled to room temperature. Through tempering treatment, on the one hand, the brittleness of the cast piece after quenching is improved, and its toughness is improved, which prepares for subsequent working, and on the other hand, the microstructure of the cast piece is fully martensitized.

[0037] After the tempering treatment, the obtained castings are placed into a normalizing furnace at a temperature of 850℃ for constant temperature keeping for 2.5h, and then taken out of the furnace and air-cooled to room temperature. Through the normalizing treatment, the martensite structure is further refined, and the performance of the castings is further improved.

[0038] Through the above-mentioned continuous three times of heat treatment, the castings obtain excellent martensite structure, which prepares for the subsequent preparation of the hammer head with high strength and high wear resistance.

[0039] (4) Hot rolling forming: after the castings after the heat treatment in step (3) are sawn, they are first heated to 1250℃, and then once hot rolling is carried out at this temperature with a reduction of 25%, and then twice hot rolling is carried out at a temperature of 1100℃ with a reduction of 15%, and then thrice hot rolling is carried out at a temperature of 950℃ with a reduction of 10%, and after the hot rolling, water cooling is carried out to room temperature.

[0040] (5) Annealing treatment: the hammer head after the hot rolling in step (4) is placed into an annealing furnace at a temperature of 500℃ for heat preservation for 3h, and then furnace cooling is carried out to 200℃, and then natural cooling is carried out to room temperature after taking out of the furnace, and the wear-resistant crusher hammer head is obtained.

[0041] Example 2

[0042] A wear-resistant crusher hammer head comprises the following components in weight percentage:

[0043] C 1.5%, W 0.8%, Cr+V 30%, Ni+Mo 3%, Cu 1.0%, Mn 2.5%, Pb 0.2%, impurities less than 0.1%, and the rest is Fe; wherein the weight ratio of Cr+V to Ni+Mo is 10:1.

[0044] In the Cr+V, the weight ratio of Cr to V is 2:1.

[0045] In the Ni+Mo, the weight ratio of Ni to Mo is 1:2.

[0046] A preparation method of a wear-resistant crusher hammer head comprises the following steps:

[0047] (1) Feeding and melting: the required iron raw materials are calculated according to the above-mentioned formula, and then all the iron raw materials are added into a smelting furnace to be melted into molten iron, and when the temperature of the molten iron is stabilized at 1600℃, pure aluminum is added for deoxidization to obtain refined molten iron;

[0048] (2) Casting: Put 3.3% of the modified modifier in the mass of the molten iron into the bottom of the ladle, the modified modifier is a rare earth modifier with a brand of FeSiMg8RE7; then pour the molten iron after refining and deoxidation in step (1) into the ingot mold, keep it at 1480-1500℃ for 3h, and then cool it to room temperature to obtain a cast part; the addition of the modified modifier is beneficial to improve the toughness of the cast part after forming;

[0049] (3) Heat treatment: after taking out the cast part obtained in step (2), polish the riser position and corner position, then first put it into a quenching furnace with a temperature of 1200℃ and keep it constant for 3h, cool it to 850℃ in the furnace, take it out and oil cool to 200℃, and finally air cool to room temperature. Through quenching treatment, the microstructure in the cast part is martensitic to obtain high-hardness martensitic structure.

[0050] After quenching treatment, the obtained cast part is put into a tempering furnace with a temperature of 500℃ and kept constant for 4.5h, then taken out and air cooled to room temperature. Through tempering treatment, on the one hand, the brittleness of the cast part after quenching is improved, and its toughness is improved, which prepares for subsequent working, and on the other hand, the microstructure of the cast part is fully martensitic.

[0051] After tempering treatment, the obtained cast part is put into a normalizing furnace with a temperature of 900℃ and kept constant for 2h, and then taken out and air cooled to room temperature. Through normalizing treatment, the martensitic structure is further refined, and the performance of the cast part is further improved.

[0052] Through the above-mentioned continuous three times of heat treatment, the cast part obtains excellent martensitic structure, which prepares for subsequent preparation of hammer head with high strength and high wear resistance.

[0053] (4) Hot rolling forming: after sawing the cast part after completing heat treatment in step (3), then heat rolling treatment is carried out, and the cast part is rolled into the required hammer head shape, and after the hot rolling is completed, it is naturally cooled to room temperature;

[0054] The process conditions of the hot rolling treatment are: first heated to 1250℃ for primary hot rolling with a reduction rate of 25%, then cooled to 1100℃ for secondary hot rolling with a reduction rate of 10%, and then cooled to 950℃ for third hot rolling with a reduction rate of 5%, and after the hot rolling is completed, it is water cooled to room temperature.

[0055] (5) Annealing treatment: put the hammer head after hot rolling in step (4) into an annealing furnace with a temperature of 550℃ and keep it constant for 3h, then cool it to 200℃ in the furnace, take it out and naturally cool it to room temperature, and obtain the wear-resistant crusher hammer head.

[0056] Comparative Example 1

[0057] The difference from Example 1 is that the weight ratio of Cr+V to Ni+Mo is 5:1.

[0058] Comparative Example 2

[0059] The difference from Example 1 is that the heat treatment process is annealing treatment, and the process conditions are: holding for 2h in an annealing furnace at 900℃, then furnace cooling to 300℃, and air cooling to room temperature after furnace discharge.

[0060] The wear-resistant crusher hammer heads prepared in the above Example 1 and Example 2 and Comparative Documents 1 and Comparative Example 2 are subjected to performance testing, and the results are shown in Table 1 below.

[0061] Table 1

[0062]

[0063]

[0064] From the data comparison in Table 1 above, it can be seen that the crusher hammer head obtained by the method of the present application has the characteristics of high hardness and appropriate toughness, good wear resistance, and long service life.

[0065] The wear-resistant crusher hammer head and the preparation method thereof have the following advantages:

[0066] 1. By controlling the total amount of the elements Cr+V which mainly play a strengthening role, the matrix strength of the crusher hammer head is effectively improved, which lays the foundation for the improvement of wear resistance; by controlling the total amount of the elements Ni+Mo which mainly play a toughening role, the toughness of the matrix is improved on the basis of strengthening; and by controlling the ratio of Cr+V to Ni+Mo, the ratio of strengthening to toughening is adjusted and controlled, so that the strength and toughness of the wear-resistant crusher hammer head are controlled as a whole, thereby preventing the occurrence of insufficient strength or insufficient toughness, etc.

[0067] 2. On the basis of the toughening of the formula, the use of a modified modifier in the forming process further plays a role in adjusting the toughness;

[0068] 3. By designing the three continuous heat treatment processes of quenching, tempering and normalizing in sequence, the microstructure of the castings is fully transformed into high-hardness martensite structure with the purpose of grain refinement, which effectively improves the overall mechanical strength of the castings, endows the hammer head after rolling with good wear resistance and crack resistance, and thus improves the service life thereof.

[0069] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation made by using the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A wear-resistant crusher hammer, characterized in that, The components include the following components by weight percentage: The composition is as follows: C 1.2–1.8%, W 0.5–0.8%, Cr+V 25–30%, Ni+Mo 0.5–5%, Cu 0.5–1.5%, Mn 2–3%, Pb 0.2–0.35%, impurities less than 0.1%, and the remainder being Fe; wherein the weight ratio of Cr+V to Ni+Mo is 10:1 to 20:

1. In the Cr+V mixture, the weight ratio of Cr to V is 1:1 to 3:

1. In the Ni+Mo mixture, the weight ratio of Ni to Mo is 1:1 to 1:

3.

2. A method for preparing a wear-resistant crusher hammer as described in claim 1, characterized in that, Includes the following steps: (1) Charging and melting: Calculate the required iron raw materials according to the formula and add them to the smelting furnace to melt into molten iron. When the temperature of the molten iron is stable at 1550-1600℃, refine and deoxidize it. (2) Casting: Place the modifier at the bottom of the ladle, then pour the refined and deoxidized molten iron from step (1) into the ingot mold, keep it warm and solidify, and then cool it to room temperature to form a casting. (3) Heat treatment: Take out the casting obtained in step (2), grind the edges and corners, and then perform quenching, tempering and normalizing treatment in sequence; The quenching process conditions are as follows: quenching temperature 1150~1250℃, holding time 2~3.5h, then furnace cooling to 800~900℃, oil cooling to 200~300℃ after furnace removal, and finally air cooling to room temperature. The tempering process conditions are: tempering temperature 450-550℃, holding time 4.5-5h, and then air-cooled to room temperature after removal; The normalizing process conditions are: normalizing temperature 850-900℃, time 2-3h, and then air cooling to room temperature after being taken out of the furnace. (4) Hot rolling: After the heat treatment in step (3) is completed, the casting is sawn and then hot rolled to form the desired hammer head shape. After hot rolling, it is naturally cooled to room temperature. (5) Annealing treatment: The hot-rolled hammerhead from step (4) is placed in an annealing furnace for annealing treatment to obtain the wear-resistant crusher hammerhead.

3. The method for preparing a wear-resistant crusher hammer according to claim 2, characterized in that, In step (4), the hot rolling process conditions are as follows: first, heat to 1250℃±30℃ for a first hot rolling, then cool to 1100℃±30℃ for a second hot rolling, then cool to 950℃±30℃ for a third hot rolling, and after the hot rolling is completed, cool to room temperature with water.

4. The method for preparing a wear-resistant crusher hammer according to claim 3, characterized in that, The reduction rate of the first hot rolling is 25-30%, the reduction rate of the second hot rolling is 10-15%, and the reduction rate of the third hot rolling is 5-10%.

5. The method for preparing a wear-resistant crusher hammer according to claim 2, characterized in that, In step (5), the annealing process conditions are: annealing temperature 500-550℃, holding temperature for 3-4 hours, then cooling to 200℃ in the furnace, and then naturally cooling to room temperature after being removed from the furnace.

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