Effects of Alloying Elements (Cr, Mo, Ni) on Wear Resistance and Impact Performance of Mining Pump Components

In the material design of mining pump components—such as slurry pump impellers, liners, and casings—the proper selection of alloying elements plays a decisive role in wear resistance and impact performance. Among them, chromium (Cr), molybdenum (Mo), and nickel (Ni) are the most commonly used and critical elements. They significantly improve the service performance of pump components under harsh mining conditions by regulating microstructure and matrix properties.

Chromium (Cr) is the key element for enhancing wear resistance. High chromium content promotes the formation of numerous hard alloy carbides, which are uniformly distributed in the metallic matrix and effectively resist abrasive wear caused by hard particles in slurry. Consequently, high-chromium alloys are widely used in high-wear areas, such as impellers and liners. However, excessive chromium can increase material brittleness, and if carbides are too large or continuous, cracks may form under impact loads, reducing impact resistance.

Molybdenum (Mo) is often added as a secondary strengthening element. Mo refines the grain structure, improves carbide morphology, and enhances matrix high-temperature strength and temper stability. In practical applications, molybdenum helps alleviate the brittleness caused by high chromium, improving the overall performance of the material under impact and complex stress conditions, thereby extending pump component service life.

Nickel (Ni) primarily enhances the toughness and impact resistance of the pump component matrix. Ni stabilizes the austenitic structure and improves the material’s ability to absorb impact and vibration, effectively inhibiting crack initiation and propagation. In mining environments with high-impact wear or fluctuating operating conditions, the addition of nickel significantly improves component reliability.

In summary, optimizing the performance of mining pump materials is not the result of a single element, but of the synergistic effect of Cr, Mo, and Ni. By carefully controlling the content of each element, a balance between high-hardness wear phases and a tough matrix can be achieved, meeting the dual requirements of wear resistance and impact performance for mining pump components.