How to balance "hardness" and "toughness" in spare part materials?

Mining spare parts often operate under dual conditions of high wear and strong impact. However, there is typically a trade-off between material hardness and toughness: high-hardness materials (e.g., high-chromium cast iron) offer excellent wear resistance but are prone to brittleness and cracking, while high-toughness materials (e.g., ordinary carbon steel) resist impact well but suffer from poor wear resistance. An imbalance between the two can drastically reduce the service life of spare parts.

Three key approaches enable this balance: first, bimetallic composite technology. For example, crusher liners adopt a bimetallic composite structure—with a high-chromium cast iron surface layer (HRC60+, for wear resistance) and a ductile iron core (impact toughness ≥15J/cm², for crack resistance)—to achieve both wear and impact resistance. Second, precision heat treatment. Scraper conveyor chains undergo "modulation heat treatment (quenching + high-temperature tempering)," resulting in a material hardness of HRC28-32 and impact toughness ≥60J/cm², suitable for both material impact and friction. Third, condition-specific material selection. For high-wear, low-impact scenarios (e.g., ball mill grinding media), prioritize hardness by choosing NM500 wear-resistant steel (HRC≥48); for high-impact, low-wear scenarios (e.g., jaw crusher swing jaws), prioritize toughness by selecting Q690D high-strength steel (impact toughness ≥34J/cm²).

This balance is not a "compromise" but a precise alignment of "operating requirements with material performance" through technical means. It can extend the service life of spare parts by over 30% and reduce downtime losses.