The crusher hammer is one of the core parts of the hammer crusher. It is arranged on the hammer shaft of the crusher rotor and directly hits the material when the hammer crusher is in operation. Crusher hammers play an important role in various fields.
According to different types of crushed materials, crusher hammers also have different classifications and they on the market can be divided into two types according to the manufacturing process: casting and forging, but their wear resistance is different. Due to the material that it is crushed, the hammer needs good abrasion resistance, and the shank needs sufficient toughness.
hammer crusher working in Pakistan
Different types of crusher hammer materials
Forging crusher hammer
Suitable for pebbles, coal gangue, limestone, etc. The hammer of the forging crusher uses high-quality steel used in the train wheel (material 65Mn, good impact resistance, strong toughness, good abrasion resistance).
The metal blank is repeatedly forged by the forging machine to deform it to obtain certain mechanical properties, shape, and size. After a special quenching and heat treatment, it can ensure that the working area of the hammer has high hardness and high wear resistance.
forged hammer has the character of high hardness and high wear resistance
Forging can eliminate defects such as as-cast looseness caused by the metal during smelting, and optimize the microstructure. At the same time, the mechanical properties of forgings are generally better than that of castings due to the preservation of the complete metal streamline. Forged hammerheads are popular with customers because of their low price, economy, and durability.
High Manganese Steel Hammer Head
High-manganese steel is the most common and widely used material. It is often used in the production of wear-resistant parts of the hammer crusher no matter it is big or small. High-manganese steel crusher hammer has good toughness, good workmanship, and low price.
Its main characteristics under the action of a large impact or contact stress, the surface layer will rapidly undergo work hardening, and its work hardening index is 5-7 times higher than other materials, and the wear resistance is greatly improved.
However, the hammer of high manganese steel crusher has higher requirements on the overall performance of the crusher. If the physical impact force is insufficient or the contact stress is small in actual work, the surface cannot be rapidly processed and hardened, so that it cannot exert its wear resistance.
High steel hammer head
Therefore, we advise the majority of customers should choose according to the actual parameters of the equipment before use, and if necessary, they can modify the equipment to make the most of its economic benefits.
However, the high toughness of high manganese steel is unmatched by other wear-resistant materials. In addition to being used in the production of crusher hammerheads, Mn13, Mn13Cr2, and Mn18Cr2 are also suitable for strong impact conditions such as large and medium-sized crusher tooth plates.
High chromium alloy crusher hammer
High chromium alloy crusher has excellent hardness and is a high-quality wear-resistant material. It has been widely used in fine crushers and impacts crushers with supporting hammer frames.
High chromium composite hammer, that is, at about 20% chrome, it’s used for more abrasive applications such as gold ore, glass recycling, and shell processing. high manganese steel is used for the hammer handle, and high chromium alloy is used in the working area of the hammerhead.
High chromium hammer head
The two are compounded to make the head of the hammer high hardness, while the hammer shank high toughness. The respective advantages of the materials overcome the shortcomings of a single material and meet the performance requirements of the hammerhead.
High chromium alloy crusher hammer is particularly suitable for crushing high hardness materials, such as quartz stone and basalt. However, the traditional manufacturing process is complicated, the process requirements are strict, and the price is high.
Compared with other materials, hard alloy hammer have higher hardness, flexural strength, and impact, thermal fatigue resistance, good thermal hardness, low cost, etc., It also solves the cracks, desoldering, and collapse that are easy to occur in high manganese materials mouth, drop the block and so on.
- Extraordinary high wear resistance, more than 20 times the high manganese steel hammer.
- Good resistance to mechanical and thermal shock
- a wide range of applications basically can be adapted to all broken industries.
The main factor affecting the wear resistance and service life of the crusher hammerhead is the silicon dioxide content in the stone. The technology under the modern industry shows that the use of hard alloy hammerheads has good wear resistance.
Carbide hammer head
Of course, some manufacturers will also improve the hammerhead. For example, the thickness of the hammer crusher head is increased by 15mm, the end width is increased by 20mm, the length of the suspension hole to the end is increased by 10mm. The radius has been changed from 90mm to 75mm to improve the comprehensive performance of the crusher hammerhead.
The crusher hammerheads that are cast with two different metal liquids are bimetallic. While the bimetallic hammerheads ensure the toughness of the hammer handle, the hammerhead also has the hardness and wear resistance.
The temperature of the bimetal hammerhead during quenching is critical. Generally, the appropriate quenching temperature is selected according to the thickness of the part wall. The higher the quenching temperature, the higher the hardenability. Therefore, it is necessary to formulate a reasonable casting and heat treatment processes.
Bimetal hammer head
Impact of Crusher Hammer Casting
If the crusher hammer is not cast properly, it can cause defects such as blowholes. When the design of the crusher hammer head pouring system is not correct, the eddy current generated by the metal liquid will wrap the gas and cause the generation of pores;
When the hammer is cast with a terrible situation of exhaust gas, the gas cannot be discharged from the mold will also cause the pores. We strictly control the pouring temperature during pouring, and can not be interrupted evenly during pouring. To facilitate the venting of the mold, inclined pouring can be used.
hammer of pcz hammer crushers
After being used, the hammer of the crusher will wear to different degrees. Due to the low-impact working conditions, the work hardening effect of the surface of the hammer will also increase. The wear of the hammer refers to the surface of the metal hammer under the action of mechanical force so that is will gradually detach from the mother’s body, change the original performance of the hammer.
How to extend the service life of the crusher hammer?
Information about the casting process
when we making crusher hammer, you have to master a lot of information which tells people what to do can cast high- quality crusher hammers. Let just take the high chromium hammers as an example, the information as following:
Grade and chemical composition of high chromium cast iron (%)
Specification for the heat treatment of high chromium cast iron
|KmTBCr12||920-980 ℃ for 2-6h||200-300 ℃ heat preservation for 2-8h|
|KmTBCr15Mo||920-980 ℃ for 2-6h||200-300 ℃ heat preservation for 2-8h|
|KmTBCr20Mo||960-1020 ℃ for 2-6h||200-300 ℃ heat preservation for 2-8h|
|KmTBCr26||960-1060 ℃ for 2-6h||200-300 ℃ heat preservation for 2-8h|
6 Simple rules you have to follow during the crushing process
- During the working process of the crusher, uniformly add materials to the crushing cavity to avoid single-sided wear of the hammerhead.
- When the nature of the material changes, timely change the working parameters of the crusher to avoid the wear of hammer.
- When installing the hammerhead, it should be in stable contact with the surface of the machine.
- When stopping, check the distance between the hammerhead and the stern plate to prevent the accumulation of material.
- Control the moisture content of the minerals, especially during the rainy season, try not to shovel the minerals with lower terrain and more water, if possible, it is better to dry the minerals before entering the crusher.
- When metal objects or liners fall off in the crusher, it is easy to cause hammer disks, purlins to be damaged or bent, or to cause accelerated hammer headwear and damage. Therefore, once we find that situation, we must shut down the machine and remove the foreign objects or liners.