The Core Pain Point of Cone Crusher Extrusion Crushing: The Local Peeling Mechanism And Control of The Crushing Wall And Rolling Bowl Wall

During the operation of the cone crusher, the crushing chamber composed of the crushing wall (moving cone liner) and the rolling bowl wall (fixed cone liner) is the key area for achieving material lamination and extrusion crushing. Compared to uniform wear, local peeling is a more destructive form of failure. It usually manifests as the detachment of block or sheet metal materials on the working surface of the lining plate, forming pits or grooves. This failure not only directly shortens the service life of the lining plate, but also has a series of chain effects on crushing efficiency, product particle size, equipment stability, and operational safety.

1、 Mechanism of local peeling failure: fatigue and brittle fracture under high stress

The essence of local peeling is the "fatigue brittle fracture" composite failure of the lining surface or sub surface material under complex stress, which can be summarized as the following stages:

Crack initiation: During the squeezing and crushing process, the surface of the lining plate is subjected to extremely high cyclic compressive stress. Hard particles in materials, such as quartz, act as stress concentration points and can cause microcracks on metal surfaces or at brittle carbide/inclusion interfaces. In addition, the instantaneous impact stress caused by abnormal events during operation (such as excessive iron and uneven feeding) may also directly lead to the formation of microcracks.

Crack propagation: Under sustained cyclic loading, these microcrack tips become new stress concentration points. Cracks gradually propagate inward and outward along the path of least resistance in the material, such as grain boundaries and hard phase boundaries. In an environment of multi-directional compressive stress, the propagation mode of cracks usually manifests as transverse propagation parallel to the surface.

Material peeling: When adjacent crack networks are interconnected, or when a single crack extends to a critical size, the material block on top of them loses effective support from the matrix and undergoes brittle fracture during subsequent compression or unloading processes, falling off from the body and forming macroscopic visible peeling pits.

2、 Analysis of Key Causes of Local Peeling

Multiple factors acting alone or in combination can significantly increase the risk of local peeling:

Material characteristics and feeding conditions

High hardness and high abrasion materials, such as granite, quartzite, etc., have severe cutting and chiseling effects on the surface of the lining plate, and are not easily broken, resulting in extremely high contact stress and accelerating crack initiation.

Excessive or uneven distribution of feed particles: Excessive feed blocks can cause local peak stresses that far exceed the design value. If the feeding is biased towards one side, it will cause local overload in the crushing chamber, resulting in eccentric wear and stress concentration zones.

The performance and quality of wear-resistant components themselves

Mismatch between material toughness and strength: Materials selected for the pursuit of high hardness to resist wear (such as some high chromium cast iron) may have relatively insufficient fracture toughness and impact toughness, and have weak resistance to crack initiation and propagation under high stress extrusion conditions.

Internal defects and poor organization: Pores, shrinkage porosity, inclusions generated during the casting process, or uneven organization and excessive internal stress caused by improper heat treatment, can all become natural sources of cracks, significantly reducing the actual fatigue strength of the material.

Unreasonable structural design: If the support ribs on the back of the lining plate and the geometric shape of the thickness transition area are not reasonable, additional stress concentration may occur during operation.

Equipment operation and maintenance factors

Excessive iron and overload: Metal foreign objects that have not been removed by the iron remover entering the crushing chamber, or forcibly starting after material blockage, can generate catastrophic instantaneous ultra-high impact stress, which can directly cause the lining plate to crack.

Installation and assembly issues: Insufficient filling (uneven zinc or resin coating) or gaps between the lining plate and the body (moving cone, fixed cone). During equipment operation, the lining plate will generate micro movements under load, resulting in uneven support and local high stress, which can easily cause fatigue peeling.

Poor lubrication and cooling: Poor lubrication of key friction pairs such as spindle bushings may cause abnormal equipment vibration, transmit additional dynamic loads to the crushing chamber, and exacerbate lining fatigue.

3、 Systemic consequences caused by local peeling

Destroying the broken cavity profile and deteriorating process indicators: The pits formed by peeling damage the preset and smooth cavity curve, resulting in poor material flow, reduced laminated crushing effect, widened product particle size distribution, decreased fine-grained yield, and increased energy consumption.

Causing chain damage and shortening equipment lifespan: detached metal blocks may get stuck at the discharge port or enter downstream equipment, causing secondary damage. The irregular surface of the crushing chamber will intensify vibration, and abnormal vibration loads may be transmitted to core components such as the spindle, gears, and bearings, shortening their service life.

Increased safety risks and maintenance costs: Peeling is an unpredictable and sudden failure that may trigger unplanned downtime. At the same time, the lining plate is often scrapped before reaching a uniform wear life, significantly increasing the cost of wear-resistant parts produced per ton of ore.

4、 Systematic control strategies and practical directions

Reducing the risk of local peeling requires systematic control throughout the entire process from material selection, design, manufacturing to use and maintenance:

Applicability Material Selection and Quality Control

Seeking a balance between material hardness, toughness, and strength that is suitable for specific working conditions based on the hardness and abrasiveness of specific materials. For high stress extrusion conditions, modified high manganese steel or special alloy steel with higher toughness can be considered.

In the procurement process, strengthen the acceptance requirements for the internal quality (such as ultrasonic testing) and mechanical properties (especially impact toughness) of liner castings, and control defects from the source.

Optimize structural design and installation process

Optimize the lining structure through finite element analysis (FEA), improve stress distribution, and avoid sudden changes in geometric shape.

Strictly follow the installation specifications to ensure 100% contact between the liner and the body, and even and firm filling layer, which is the basis for preventing liner loosening and micro fatigue.

Standardize production operations and monitor implementation status

Set up and maintain a reliable iron removal system to prevent iron overload. Ensure uniform and continuous feeding, avoid cavity blockage and impact overload.

Establish a regular lining inspection system and use downtime to check for early signs of peeling such as micro cracks and dents on the surface, achieving predictive replacement.

Monitoring equipment operating parameters (such as main motor current, lubrication system pressure and temperature, vibration values), abnormal data is often a precursor to the deterioration of internal stress state of the equipment.