ISO 17463 pdf download

ISO 17463 pdf download Paints and varnishes — Guidelines for the determination of anticorrosive properties of organic coatings by accelerated cyclic electrochemical technique
Scope
This International Standard gives guidelines on how to perform accelerated cyclic electrochemicatechnique(ACET) with organic protective coatings on metals.
This International Standard specifies:
the instrumentalassembly;
the execution of an ACET test and the considerations relative to the samples and electrochemicalcell, test parameters and procedure.
This International Standard also provides guidelines for the presentation of experimental results andother type of information obtained.
Some typical examples are shown in an informative annex
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies
ISO 2808, Paints and varnishes – Determination offilm thickness
ISO 3270, Paints and varnishes and their raw materials — Temperatures and humidities for conditioning
and testing
ISO 16773-1, Electrochemical impedance spectroscopy (ElS) on coated and uncoated metallic specimens -Part 1: Terms and definitions
ISO 16773-2:-1), Electrochemical impedance spectroscopy (EIS) on coated and uncoated metallicspecimens – Part 2: Collection ofdata
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16773-1 and the followingapply.
3.1
cathodic polarizationapplication of a potential Upol more negative than the open-circuit potential Uocp for a fixed period ofpolarization time tpol
Note 1 to entry: This value is defined by the operator.
3.2
relaxation time
trelaxtime between the cathodicpolarization andthe beginningoftheelectrochemicalimpedance spectroscopy(EIS) measurement
Note 1 to entry: This value is defined by the operator.
3.3
cathodic disbondingfailure of adhesion between a coating and a metallic surface that is directly attributable to cathodicreaction conditions and that is often initiated by a defect in the coating system, such as accidentaldamage, imperfect application or excessive permeability of the coating
[SOURCE:ISO 15711:2003,definition 3.1]
3.4
cathodic potentialp
potential difference between an applied potential Upol and the open circuit potential Uocp
4 Principle
4.1General
The initial state of the coating system is characterized by an electrochemical impedance spectroscopy(EIS) measurement (EISn. – see Figure 1). Then a cathodic polarization (Pn) is applied for a certainperiod of time (tool) followed by the relaxation process (rn) over the time (trelax). Finally the new stateof the coating system is characterized by a second ElS measurement (ElS,). These steps define a cyclewhich can be repeated n number of times (n is the number of cycles).
NOTETypically six cycles are used.