Overview
EN ISO 4526:2004 - "Metallic coatings - Electroplated coatings of nickel for engineering purposes" specifies requirements for electroplated nickel and nickel-alloy coatings applied to ferrous and non‑ferrous substrates for engineering use. The standard defines the scope, required information for the electroplater, designation and labelling rules, technical requirements, sampling and test methods. Binary nickel alloys in which nickel is a minor constituent are excluded.
Key Topics
- Scope and purpose: Requirements for engineering nickel coatings intended to improve hardness, wear and corrosion resistance, load-bearing and heat-scaling behavior, and to act as diffusion barriers or for salvage repairs.
- Designation system: How to specify coating sequences, basis metal, thickness and heat treatments (example: NiCo(35)25 denotes Ni–Co with 35% Co and 25 µm thickness; [SR(210)1] denotes stress relief at 210 °C for 1 h).
- Types of nickel coatings: Symbols and categories such as sulfur‑free (sf), sulfur‑containing (sc), and particle‑dispersed (pd). Nickel alloy symbols include NiCo, NiFe, NiMo, NiW, NiMn, NiP with nominal composition ranges.
- Information to purchaser/electroplater: Mandatory items for orders - designation, special test specimens, significant surfaces, final finish, acceptable defect size/count, areas with minimum thickness, test methods, tensile strength and stress‑relief or hydrogen‑embrittlement requirements, sampling plan.
- Technical requirements and tests: Coverage of thickness, adhesion, porosity, internal stress, ductility and hydrogen‑embrittlement controls. Annexes provide typical bath compositions and operating conditions (Annex A), thickness test methods (Annex B), porosity and ferroxyl tests (Annexes C–D), and application guidance (Annex E).
- Limitations: Note on sulfur‑containing additives - can improve hardness but may cause embrittlement at elevated temperatures (effect can appear at ~150 °C with sufficient time).
Applications
- Surface engineering where improved wear resistance, hardness, corrosion resistance, or dimensional restoration is required
- Protective and functional coatings on automotive, aerospace, tooling, hydraulic components, and industrial machinery
- Specification for plating contracts, procurement documents, engineering drawings and quality control plans
Who Uses This Standard
- Electroplating shops and surface‑treatment suppliers
- Design and materials engineers specifying coatings
- Procurement and quality assurance professionals
- Test laboratories assessing thickness, adhesion and porosity
Related Standards
EN ISO 4526 references multiple normative standards for test methods and terminology, for example:
This standard is essential for anyone specifying or supplying electroplated nickel coatings for engineering parts and provides a uniform framework for designation, testing and acceptance criteria.