DEFSTAN 03-24/5(2008) : 2008

Foreword
0 Introduction
1 Scope
2 Warning
3 Normative References
4 Definitions
  4.2 Process control schedule
  4.3 Purified water
  4.4 Significant surface
5 Information to be Supplied by the Purchaser
6 Process Control
7 Applications and Limitations
  7.1 Applications
  7.2 Compatibility with explosives, propellants and
      pyrotechnics
  7.3 Limitations
8 Process Requirements
  8.1 Surface Preparation
  8.2 Anodizing
  8.3 Washing
  8.4 Sealing
  8.5 Drying
  8.6 Re-Anodizing
9 Inspection and Test
  9.1 Processing
  9.2 Frequency of testing
  9.3 Appearance
  9.4 Tests for electrical insulation (sealed coatings only)
  9.5 Corrosion test
  9.6 Sealing quality
Annex A - Chromic Acid Anodizing Process for Aluminium and
          Aluminium Alloys
  A.1 Electrolyte
  A.2 Cathode
  A.3 Suspension or Jigging
  A.4 Anodizing Procedure
      A.4.1 Standard process
      A.4.2 Alternative process for castings
      A.4.3 Alternative process for high zinc aluminium alloys
            in the overaged condition
Annex B - Analysis of Chromic Acid Electrolyte
  B.1 Analysis of Chromic Acid Electrolyte
  B.2 Analysis for Total Chrome
      B.2.1 Reagents
      B.2.2 Procedure
            B.2.2.1 Standardisation of ferrous ammonium
                    sulphate
            B.2.2.2 Determination of total chrome
            B.2.2.3 Calculation
  B.3 Analysis for Free Chromic Acid (Used Electrolyte)
      B.3.1 Reagent
      B.3.2 Procedure
      B.3.3 Calculation
  B.4 Analysis for Free Chromic Acid (Fresh Electrolyte)
      B.4.1 Reagents
      B.4.2 Procedure
      B.4.3 Calculation
  B.5 Analysis for Chloride
      B.5.1 Reagents
      B.5.2 Procedure
      B.5.3 Calculation
  B.6 Analysis of Chromic Acid Electrolyte
      B.6.1 Reagents
      B.6.2 Procedure
      B.6.3 Calculation
Annex C - Stripping Solutions for the Removal of Anodic
          Coatings
  C.1 Preferred Solution
  C.2 Alternative Solutions
Annex D - Chromic Acid Anodizing for the Flaw Detection
          of Defects in Aluminium Alloy Bars, Extrusions,
          Sheet, Rolled Plate, Forgings and Machined Items
  D.1 Applications
  D.2 Special Requirements
  D.3 The Characteristics of Defects Revealed by Chromic
      Acid Anodizing
      D.3.1 Guidance
      D.3.2 Cracks or exfoliation corrosion
      D.3.3 Cracks or folds not detectable by a yellow
            brown stain
      D.3.4 Laps or folds in forged items
      D.3.5 Intercrystalline corrosion
      D.3.6 Machining damage
      D.3.7 Incipient melting at grain boundaries
  D.4 Re-Anodizing for Inspection Purposes
  D.5 Comparison With Penetrant Methods of Flaw Detection
Annex E - Procedure for Anodizing Hollow Items such as
          Tanks, Long Tubes and Extrusions
  E.1 Cleaning
  E.2 Small Tanks
  E.3 Other Tanks
  E.4 Combination Tanks
  E.5 Hollow Items
  E.6 Repairs
  E.7 Flow of Electrolyte
  E.8 Auxiliary Cathodes
  E.9 Cathode Material

Specifies the requirements for chromic acid anodizing of aluminium and aluminium alloys.