80-T-35-3000 CADMIUM-PLATING OF STEEL

The support fixtures shall not have any bare copper surfaces. It is not permitted to use tying wires made from copper. 4.3 Materials and components
Components to be cadmium–plated must be stress–free (treatment per 80–T–36–1020). All welding and mechanical operations must have been completed so that subsequent work will not damage the applied surface protection. In addition, all parts must be free from surface flaws and contamination. Components for which full electrical surface conductivity has to be ensured (e.g. electrical components) must not be post–treated after cadmium–plating and passivation. Component surfaces which are not to be cadmium–plated must be masked. Deep etching varnish or galvanic tape can be used for masking. Holes, especially close–tolerance holes, must be sealed with conical rubber plugs prior to cleaning. 5 PROCESS 5.1 5.1.1 Pretreatment Cleaning with organic solvents (cold cleaning agents)
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3 PREREQUISITES 3.1 Engineering documents
The layer thickness shall be stated in the drawing and the work plan. 3.2 Personnel
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1 SCOPE AND APPLICATION This process specification describes cadmium–plating of steels with a tensile strength x 1450 N/mm2 for corrosion protection. The process shall be applied if the manufacturing documents specify surface protection in accordance with 80–T–35–3000 or LN 9368, ident. No. 3000, 3001, 3002. Cadmium–plating is an electrolytic process in which cadmium is deposited onto steel components from a cyanide electrolyte by direct current. The cadmium layer is electrically conductive and generally passivated with chromic acid to increase the corrosion resistance. The cadmium layer can be exposed to an operating temperature of 190 °C without losing its effectiveness. Unless expressly specified otherwise, cadmium coatings must be post–treated by chromium passivation according to 80–T–35–1107. 2 RELATED DOCUMENTS QVA–Z09–07–00 Surveillance of bath for chemical and galvanic surface treatment QVA–Z09–07–19 Analysis, cathodic treatment KN30XX, cadmium–plating QVA–Z09–07–32 Combined determination of free hydroxide and aluminium in alkaline surface treatment baths QVA–Z09–07–35 Determination of cyanide in surface treatment baths QVA–Z09–07–37 Determination of cadmium in surface treatment baths QVA–Z10–50–02 Thickness measurement of non–ferromagnetic layers on ferromagnetic materials by magnetic flux QVA–Z10–59–01 Salt spray test QVA–Z10–73–00 Test involving electro–deposition of a coating in a hull cell QVA–Z20–01–00 Sampling Procedures, Selection and Application 80–T–35–0014 80–T–35–0020 80–T–35–0030 80–T–35–0090 80–T–35–0095 80–T–35–0200 80–T–35–1107 80–T–35–3003 80–T–36–1020 80–T–36–3300 Cleaning with organic solvents (cold cleaning agents) Alkaline cleaning Electrolytic degreasing Rinsing Water quality Abrasive blasting –cleaning– Chromium passivation of cadmium–plated surfaces Cadmium–plating of copper alloys Heat treatment of steel Dehydrogenation of steels
80–T–35–3000
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5.Байду номын сангаас.3
Alkaline cleaning
Per 80–T–35–0020. 5.1.4 Electrolytic degreasing
Per 80–T–35–0030. 5.1.5 Pickling
Prior to cadmium–plating, alkaline liquid residues and oxide traces adhering to the component must be removed in a pickling bath in accordance with data sheet 3 or 4 of 80–T–35–3003. 5.1.6 Nickel–plating
Earlier issue: 11/98
Copying of this document, and giving it to others and the use or communication of the contents thereof, are forbidden without express authority. Offenders are liable to the payment of damages. All rights are reserved in the event of the grant of a patent or the registration of a utility model or design.
Per 80–T–35–0014. 5.1.2 Mechanical cleaning
Per 80–T–35–0200. Minor corrosion spots on components can be removed with emery cloth or steel brushes.
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Only adequately trained personnel shall be permitted to carry out cadmium–plating work steps. 4 MATERIALS AND EQUIPMENT 4.1 4.1.1 Bath systems Cadmium bath
Process Specification
Cadmium–Plating of Steel
80–T–35–3000
Issue: 05/01 Page 1 / 7
Contents
1 2 3 4 5 6 7 8 Scope and Application Related Documents Prerequisites Materials and Equipment Process Quality Assurance Safety and Health Process Flow Chart
All directives are originally compiled, checked and approved in the German language. In case of discrepancies which could result from possible translation errors or wrong interpretation of the English text, the German version of these directives shall always be binding.