Ni-Hard Casting Manufacturer

What are the typical applications of Ni-Hard castings in the mining, concrete, and gravel industries?

1. Mining Crushing and Grinding Equipment: Due to its high hardness and wear resistance, Ni-Hard castings are widely used in key components such as ball mill liners, hydraulic breakers, grinding rollers, and conveying pipelines, maintaining a long service life during high-load ore crushing and grinding processes.

2. Concrete Mixing and Conveying Systems: In concrete mixers, conveying screws, and pump casings, Ni-Hard castings can withstand the strong impact and abrasion of concrete particles, improving equipment reliability and maintenance intervals.

3. Gravel Conveying and Sandblasting Equipment: Used in gravel conveying pipelines, sandblasting nozzles, and blower blades, Ni-Hard's high hardness and impact resistance ensure that it is not easily worn or deformed in high-speed, sand-containing media environments.

4. Other High-Abrasion Applications: Ni-Hard castings can be used in applications such as mining screens, slag conveying pumps, and steel rolling mill rolls to provide dual protection against wear and impact.

How do Ni-Hard castings perform in high-temperature, humid environments?

1. High-Temperature Oxidation Resistance: Ni-Hard alloys contain approximately 1.4–2.5% chromium and 3.4–4.75% nickel. These two elements form a dense oxide film on the surface at operating temperatures of 300–400°C, significantly enhancing oxidation resistance.

2. Corrosion Resistance in Humid Environments: Studies show that Ni-Hard castings maintain good corrosion resistance in humid or water-vapor-containing environments, mainly due to the protective oxide layer formed by chromium and the passivation effect of nickel. This results in a much lower mass loss rate under high-temperature, humid conditions compared to ordinary high-chromium white cast iron.

3. Effect of Heat Treatment on Corrosion: High-temperature quenching or tempering can adjust the proportion of retained austenite in the matrix. A moderate amount of retained austenite helps form a fine martensite-austenite mixed structure on the working surface, further improving resistance to crack propagation and corrosion cracking.

4. Practical Application Verification: In field applications of ball mill liners and gravel conveying pipelines in mines, Ni-Hard castings exhibited extremely low corrosion rates and stable mechanical properties under long-term high-temperature and humid working environments, verifying their excellent corrosion resistance.