ISO 4526:2004

Overview

ISO 4526:2004 - Metallic coatings - Electroplated coatings of nickel for engineering purposes defines requirements and a designation system for electroplated nickel and nickel-alloy coatings applied to ferrous and non‑ferrous substrates for engineering use. It covers how to specify type, thickness, and post‑treatments of engineering nickel coatings and clarifies the information purchasers must supply to electroplaters.

Keywords: ISO 4526, electroplated nickel, nickel coatings, engineering nickel coatings, nickel alloy.

Key topics and technical requirements

• Scope and limits: Applies to nickel and nickel‑alloy electrodeposits used for engineering purposes. Binary alloys where nickel is a minor constituent are excluded.
• Designation system: A standardized notation (e.g., “Electrodeposited coating - ISO 4526 - Fe / NiCo(35)25 / …”) specifies basis metal, heat treatments, under/overcoats, alloy type and nominal composition, and minimum local thickness in micrometres.
• Types of nickel: Distinguishes sulfur‑free (sf), sulfur‑containing (sc) and particle‑dispersed (pd) deposits, with sulfur thresholds and ductility guidance given (e.g., sf: < 0.005% S with ductility > 8%).
• Alloy notations: Symbols for common binary alloys (NiCo, NiFe, NiP, NiMo, NiW, NiMn) and their nominal composition ranges are provided.
• Information to supply: Purchasers should provide designation, test specimen requirements, significant surfaces, final finish, defect acceptance, thickness zones, test methods, tensile strength/stress relief needs, hydrogen embrittlement requirements, and sampling/acceptance levels.
• Testing and inspection: References and annexes cover thickness measurement methods, porosity tests (hot water porosity, modified ferroxyl), adhesion, hardness, ductility, residual stress, hydrogen embrittlement testing and sampling plans.
• Process notes: Typical plating solutions (Watts, nickel sulfamate), additive effects (hardening, stress control), and cautions (sulfur‑containing deposits can embrittle at elevated temperatures) are addressed in informative annexes.

Applications and users

• Practical applications: Wear- and corrosion-resistant components, load-bearing surfaces, salvage/restoration of worn parts, diffusion barriers, and pre‑ or post‑treatments for engineering assemblies.
• Who uses this standard:
  • Plating shops and electroplaters specifying or verifying coatings
  • Design and manufacturing engineers selecting surface finishes
  • Quality, inspection and procurement teams writing purchase orders or specifications
  • Materials and corrosion engineers assessing suitability for service environments

Related standards

ISO 4526 references multiple test-method and vocabulary standards commonly used alongside it, for example ISO 1463, ISO 2177, ISO 4516, ISO 9220, and standards addressing hydrogen embrittlement and sampling (e.g., ISO 9587, ISO 15724, ISO 4519).

Practical value: use ISO 4526 to ensure consistent specification, testing and communication of electroplated nickel coatings for reliable performance in engineering applications.