Selection and Economic Evaluation Analysis of Wear resistant Materials for Ultra Heavy duty Cone Crushers for Extremely Hard Ores

When processing extremely hard ores with compressive strength exceeding 250 MPa and high quartz content (such as basalt and granite), the ultra heavy cone crusher is subjected to extremely high impact loads, severe abrasive wear, and complex alternating stresses. Under this operating condition, the selection decision of lining material needs to be based on a thorough analysis of failure risk and a cautious evaluation of overall cost.

1、 Analysis of the necessity of using higher alloying materials

The extremely hard ore poses significantly higher mechanical performance requirements for the conical broken lining plate (rolling bowl wall, crushing wall) than ordinary working conditions. Conventional high manganese steel (such as ZGMn13) may face challenges, and improving the alloying level is a common technical response path.

High impact loads require ultra-high toughness reserves: The crushing of extremely hard ores requires enormous energy input, resulting in the lining plate being subjected to periodic high-frequency impacts. Mn22Cr2 and other high manganese steels can obtain a more stable austenite structure and higher initial impact toughness (ak value) by increasing the manganese and chromium content, effectively suppressing crack initiation and propagation, preventing brittle fracture or bulk peeling under extremely high stress, and ensuring the safe operation of equipment.

Strong abrasion requires high hardness and wear resistance: high quartz content produces micro cutting on metal surfaces. Higher alloying special alloy steels (such as medium high carbon multi-element alloy steels) can achieve higher initial hardness (HRC 45-55) and uniformly distributed hard phases through the addition of carbide forming elements (Cr, Mo, V, etc.) and heat treatment, directly resisting abrasive cutting and suitable for areas subjected to strong abrasive wear.

Fatigue resistance requirements under heavy load alternating stress: The heavy load operation of ultra heavy equipment generates significant alternating stress. Higher alloying and optimized heat treatment processes help refine grains, improve material fatigue strength, and delay the formation and propagation of microcracks caused by fatigue.

Conclusion: In the processing of ultra heavy cone crushing of extremely hard ores, the use of higher performance materials such as Mn22Cr2 or special alloy steel is usually a reasonable technical choice to cope with its harsh working conditions, avoid abnormal early failure of lining plates, and ensure production continuity. This does not mean that low-grade materials are completely unusable, but the increased risk of fracture and frequent unexpected shutdowns often result in an overall cost advantage.

2、 Comparison of Material Technology Paths: Mn22Cr2 and Special Alloy Steel

The two represent different performance enhancement ideas:

Characteristics: Mn22Cr2 (improved high manganese steel) special alloy steel (such as 40CrMnSiMoRe)

Strengthening mechanism work hardening: Depending on work impact, the surface austenite transforms into martensite, and the hardness increases from HB~200 to above HB 500. Precipitation strengthening+phase transformation strengthening: Obtaining high initial hardness and overall strength through alloy carbides and heat treatment.

The core advantage is high resilience reserve and strong resistance to overall fracture; Adaptive wear surface. The initial hardness and wear resistance are outstanding, and it performs well in the wear zone where the impact load is not strong; Performance is not heavily dependent on impact.

Limitations are considered in areas with insufficient impact, where the hardening effect is limited. Relatively low toughness, there is a risk of brittle cracking under extreme impact.

Suitable for components that are subjected to direct and severe impacts, such as moving cones and crushing walls. The lower part of the cone rolling bowl wall, or the area with relatively slow impact but severe abrasion.

In practice, the differentiated configuration of using high toughness Mn22Cr2 for the dynamic cone and high wear-resistant special alloy steel for the fixed cone is a common solution that balances safety and wear resistance.

3、 Framework for Evaluating Economic Boundaries

The core of economic evaluation is whether higher material procurement costs can be offset by longer service life, higher equipment operation rate, and lower comprehensive maintenance costs, thereby reducing the "ton ore processing cost".

Establish key evaluation indicators: ton ore processing cost

Calculation formula: Ton cost=(lining plate procurement cost+replacement labor and downtime cost)/total ore tonnage processed during the lining plate service life

Objective: To find a reasonable choice for this working condition by comparing the ton costs of different material schemes.

Cost benefit analysis model

Assumption:

Option A (Conventional Materials): The unit price is P_A, and the expected service life processing tonnage is T.A.

Option B (high-performance materials): The unit price is P_B (P_B>P_A), and the expected service life processing tonnage is T.B.

The fixed cost (labor, downtime, etc.) for a single replacement is C.

The economic equilibrium point exists when (P_B+C)/Tb<(P_A+C)/tA, that is, the ton cost of high-performance materials is lower than that of conventional materials.

Derive the critical requirement for performance improvement: TB/TA>(P_B+C)/(P_A+C)

This means that the lifespan improvement ratio of high-performance materials must exceed their price increase ratio (after considering fixed costs).

Key data and considerations in evaluation

Obtaining reliable lifespan data: This is the basis for evaluation. Reference should be made to historical data under similar operating conditions, reliable laboratory wear test comparisons, and validated cases provided by suppliers.

Quantitative downtime cost (C): Extreme hard ore production lines typically have high production capacity value. The cost of shutdown should include the production profit lost due to shutdown, additional expenses for emergency repairs, and the impact of production fluctuations on downstream processes. This part is often underestimated, but it is the key factor that affects decision-making.

Assess risk cost: The higher risk of fracture in conventional materials may lead to associated damage to other core components (such as the spindle and body), resulting in significant accidents that far exceed the losses of the lining plate itself. The improvement of operational reliability brought by high-performance materials has implicit economic value.

Considering process benefits: A more stable liner geometry helps maintain a longer discharge port stability period and better product particle size, improving downstream efficiency and product value.

4、 Systematic decision-making recommendations

Preliminary small-scale verification: Before a comprehensive replacement, 1-2 sets of high-performance lining plates can be tested to accurately record their processing tonnage, wear morphology, and impact on equipment operation stability, in order to obtain first-hand economic data.

Perform Life Cycle Cost (LCC) simulation: Based on existing data, simulate the total cost of two options over a 3-5 year period, covering factors such as procurement, replacement, downtime, risk, and residual value.

Choose a technology supported supplier: collaborate with suppliers who can provide detailed material performance reports, participate in operating condition analysis, and share real application data, rather than relying solely on price decisions.

Conclusion

For the ultra heavy cone breaking of extremely hard ores, using high-performance materials such as Mn22Cr2 or special alloy steel is usually a reasonable direction to cope with their extreme working conditions technically. Its economic viability is not necessarily established, but rather there exists a clear "cost life" equilibrium boundary.

The key to decision-making lies in quantitatively evaluating the life extension benefits and risk reduction value brought by high-performance materials through systematic data collection and analysis, and whether they are sufficient to cover the increased initial investment. When the expected lifespan increase can exceed the cost increase, or when the hidden downtime and risk costs are extremely high, investing in higher performance wear-resistant materials is usually a more advantageous choice from a long-term operational perspective. The final decision should be based on a detailed analysis of specific operating conditions, production value, and cost data.