Description

NI-HARD™ and HI-CHROME™ are high-performance cast irons renowned for their exceptional resistance to abrasion and corrosion. These alloys offer a compelling combination of hardness, toughness, and durability, making them ideal for components subjected to severe wear and aggressive environments. While both offer significant benefits, they differ slightly in their composition and resulting properties, catering to specific application needs.

NI-HARD™ (High Nickel-Chromium Cast Iron):

• Composition: Characterized by high nickel and chromium content, typically ranging from 1.5% to 4.5% nickel and 1% to 3% chromium. These alloying elements significantly enhance the material's microstructure, resulting in improved hardness and abrasion resistance.
• Properties:
  • Exceptional Abrasion Resistance: Outperforms many other cast irons and even some steels in high-abrasion applications. This is attributed to the formation of a hard, wear-resistant martensitic matrix.
  • Good Impact Resistance: Despite its hardness, NI-HARD™ possesses relatively good impact toughness, reducing the risk of brittle fracture under shock loading.
  • Moderate Corrosion Resistance: Offers better corrosion resistance than ordinary cast iron, particularly in mildly acidic or alkaline environments. Specific corrosion resistance depends on the exact alloy composition and the corrosive medium.
  • Excellent Castability: Can be cast into complex shapes with good dimensional accuracy.
• Applications: Ideal for components experiencing severe abrasive wear, including:
  • Mining equipment (crushers, mills, pumps)
  • Construction equipment (excavators, bulldozers)
  • Pulp and paper industry (valves, impellers)
  • Cement industry (mill liners, grinding balls)
  • Metal processing equipment

HI-CHROME™ (High Chromium Cast Iron):

• Composition: Primarily characterized by a high chromium content, typically exceeding 20%, often with the addition of other alloying elements to further enhance properties.
• Properties:
  • Very High Abrasion Resistance: Offers superior abrasion resistance compared to NI-HARD™, particularly in extremely harsh environments. The high chromium content forms a very hard carbide structure.
  • Excellent Corrosion Resistance: Displays outstanding resistance to a wide range of corrosive media, including acids and alkalis. This makes it suitable for applications in chemical processing and wastewater treatment.
  • High Hardness: Possesses exceptional hardness, contributing to its longevity in wear-intensive applications.
  • Good Castability (though potentially more challenging than NI-HARD™): Can be cast into various shapes, although the high chromium content might present slight challenges in casting compared to NI-HARD™.
• Applications: Best suited for highly corrosive and abrasive applications, such as:
  • Chemical processing equipment
  • Pulp and paper machinery
  • Wastewater treatment plants
  • High-temperature applications (depending on specific alloy composition)

Choosing Between NI-HARD™ and HI-CHROME™:

The choice between NI-HARD™ and HI-CHROME™ depends on the specific application requirements. If the primary concern is abrasion resistance in a less corrosive environment, NI-HARD™ may be sufficient. However, for applications demanding both superior abrasion and corrosion resistance, particularly in highly aggressive environments, HI-CHROME™ is the preferred choice. Consult with a material specialist to determine the optimal alloy for your specific needs. This may involve specifying precise chemical composition to target specific performance characteristics.