How do material hardness and particle size affect the wear rate of lining plates?

The wear rate of the lining plate (rolling bowl wall and crushing wall) of the cone crusher is highly correlated with the properties of the feed material. The hardness and particle size of the material are two fundamental parameters that affect the wear process of the lining plate through different mechanisms of action. This article is based on on-site working condition data and laboratory research, analyzing the specific effects of these two factors on the wear rate of lining plates.

1、 The influence mechanism of material hardness on liner wear

1. The difference in hardness determines the type of wear

The relative relationship between material hardness and lining material hardness directly affects the type and strength of wear mechanism. According to the theory of abrasive wear, when the hardness of the material approaches or exceeds the surface hardness of the liner, the wear rate will significantly increase.

Research has shown that for every 50MPa increase in compressive strength of materials, the service life of lining plates will be shortened by 15% to 20%. Taking typical materials as an example, granite (with higher hardness) wears the lining plate about twice as fast as limestone (with lower hardness). This is mainly because hard material particles can effectively press into the surface of the lining plate, producing cutting and chiseling effects in relative motion.

Scanning electron microscopy analysis shows that obvious chiseling pits and cutting grooves appear on the surface of the lining plate when crushing hard materials. When the hardness of the material is relatively low, the wear mechanism is mainly dominated by extrusion deformation and fatigue peeling, and the material removal rate is relatively slow.

2. The exertion of work hardening effect

High manganese steel lining materials will undergo work hardening during operation, and the surface hardness can be significantly improved. But the effective implementation of this hardening effect requires sufficient impact energy. When the hardness of the material is low, the impact energy is insufficient, and it is difficult to form an effective hardening layer on the surface of the lining plate. Instead, plastic deformation and fatigue damage may occur due to repeated squeezing.

Therefore, the matching relationship between material hardness and lining material is quite complex. Materials with excessively high hardness will directly exacerbate cutting wear, while materials with excessively low hardness may lead to insufficient work hardening of the lining plate, both of which will affect the wear process of the lining plate.

2、 The influence of material particle size on liner wear

1. Relationship between particle size distribution and wear location

The particle size composition of the feed has a direct impact on the location and rate of wear of the lining plate. Research has shown that when the feed particle size is too coarse, the crushing effect is mainly concentrated in the upper part of the crushing chamber, resulting in more severe wear on the upper lining plate and relatively lighter wear on the lower part. On the contrary, if the feeding particle size is too fine, the crushing mainly occurs in the lower part of the crushing chamber, and the wear rate of the lower lining plate will be significantly accelerated.

This uneven wear will form irregular contours on the surface of the lining plate, affecting the geometric shape of the crushing chamber, thereby reducing crushing efficiency and accelerating local wear.

2. The correlation between particle size and wear mechanism

Regarding the influence of particle size on wear, research on three body abrasive wear shows that particle size has a nonlinear effect on the wear process. In the smaller particle size range (such as 1.5 μ m to 4 μ m), fine particles may be crushed and form a friction layer on the surface of the lining plate, which actually has a certain protective effect on the lining plate. But as the particle size further increases, this protective effect disappears and is replaced by a chiseling effect on the lining plate, resulting in a significant increase in material loss.

The study on the wear of the hopper liner also confirms that the wear depth shows different patterns with the variation of particle size. Within a certain range, the wear caused by smaller particles is actually more significant, which is related to the movement mode of particles and the distribution of contact stress.

3. Impact effect of oversized particle size

When large pieces of material exceeding the design specifications are mixed into the feed, additional impact loads will be generated. Data shows that if the feed particle size exceeds the specified value by 10% (such as allowing ≤ 80mm but mixing 100mm material), it will result in an increase of about 40% in impact load. This unconventional impact not only accelerates wear, but in some cases may also cause cracks in the lining plate.

3、 The comprehensive effect of hardness and particle size

In actual production, the influence of material hardness and particle size on liner wear is additive. Hard large particle materials often cause more severe wear, while the impact of soft fine particles is relatively mild. Both factors jointly determine the amount of material removal per unit time for the lining plate.

In addition, the distribution of material particle size can also affect the state of the material layer inside the crushing chamber. Reasonable particle size composition helps to form stable laminated crushing, making the lining plate more evenly stressed; Unreasonable particle size distribution may lead to local stress concentration and accelerate local wear.

The influence of different material characteristics on liner wear

Material characteristics, wear parts, main wear mechanisms, and impact on wear rate

The overall wear and tear of high hardness materials increases, and for every 50MPa increase in cutting compressive strength, the service life is shortened by 15-20%

Low hardness materials have relatively light overall wear, extrusion deformation, and insufficient fatigue work hardening, posing a risk of fatigue damage

The upper part of the crushing chamber with coarse particle size is severely impacted and chiseled, resulting in severe local wear and irregular shape of the lining plate

Fine particle size, cutting and abrasion in the lower part of the crushing chamber, fast wear in the lower part, affecting the discharge particle size

The impact load in the local impact zone of the oversized block increases by 40%, which may cause cracks

4、 Response measures in production

The following measures can be taken to address the impact of material hardness and particle size on wear:

Pre screening: Setting up pre screening equipment before crushing to separate ultra-fine particles, making the particle size distribution of materials entering the crushing chamber more reasonable, and helping to form stable laminated crushing.

Particle size control: Strictly control the discharge particle size through the coarse crushing process to avoid oversized large pieces of material entering the medium and fine crushing process.

Material adaptation: Select the matching lining material for materials of different hardness. When dealing with hard materials, high chromium cast iron and other materials with higher hardness can be considered.

Selection of chamber type: Choose the appropriate crushing chamber type based on the composition of the feed particle size, so that the material can fill the entire crushing chamber from large to small, avoiding excessive local wear.