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Fe8Ni

Fe8Ni is an iron-nickel low-alloy steel with 8% nickel as the primary alloying element, widely applied in MIM production for parts requiring high toughness and dimensional stability.

Typical Chemical Composition

  • Nickel (Ni): 7.5%–8.5% – Main alloy element that improves low-temperature toughness, sintering densification and dimensional consistency
  • Carbon (C): ≤0.03% – Ultra-low carbon to avoid brittle carbide precipitation
  • Minor trace elements: Mn, Si (trace levels)
  • Balance: Iron

Core Material Properties

  1. Excellent Sintering Performance for MIM The nickel alloying system promotes uniform densification during sintering, delivering high compactness with minimal shrinkage deviation, ideal for micro complex thin-walled components.
  2. Superior Low-Temperature Toughness Nickel refines the ferrite matrix, eliminating low-temperature brittleness; maintains stable impact performance under cryogenic working conditions.
  3. Adjustable Mechanical Strength Strength and hardness can be boosted via carburizing, nitriding or quenching & tempering heat treatments; no precipitation hardening effect like 17-4PH.
  4. Magnetic Characteristic Ferromagnetic material, suitable for electromagnetic structural parts; not applicable for magnetic-sensitive precision electronics.
  5. Moderate Corrosion Resistance Basic rust resistance inferior to austenitic stainless steel (304/316). Surface protection such as plating, passivation or oil sealing is required for humid environments.
  6. Dimensional Stability Low thermal expansion coefficient compared to plain carbon steel, less prone to deformation during temperature cycling.

Machining & MIM Process Adaptability

  1. Metal Injection Molding (MIM) Fe8Ni powder has good fluidity for intricate micro geometries. After debinding and sintering, the part features uniform internal structure and low distortion, perfect for small mechanical structural parts with tight tolerance requirements.
  2. Compatible Surface Treatments Supports polishing, sandblasting, electroplating, nitriding and carburizing to enhance surface hardness and anti-rust capacity.
  3. Heat Treatment Options Can undergo quenching and tempering to balance strength and toughness; surface chemical heat treatment (nitriding) is commonly used to upgrade surface wear resistance.

Advantages & Disadvantages

Advantages

  • Lower raw material cost than stainless steel grades
  • Outstanding sintering shrinkage consistency, high dimensional accuracy for MIM mass production
  • Exceptional low-temperature impact resistance
  • Easy to strengthen via conventional quenching/tempering or surface hardening processes

Disadvantages

  • Poor natural corrosion resistance; extra surface coating mandatory for damp or corrosive environments
  • Magnetic, incompatible with magnetic interference-sensitive assemblies
  • No high corrosion resistance against salt spray, acid and alkali media

Typical Applications

  1. Precision Transmission Parts: Small gear components, gear sleeves, low-load gear shafts
  2. Electromagnetic Components: Miniature magnetic structural brackets, sensor housings
  3. General Industrial Hardware: Low-load connecting pins, structural supports, miniature machinery parts
  4. Automotive General Fittings: Low-stress interior structural small parts