ISO14993金属和合金的腐蚀试验箱

ISO14993金属和合金的腐蚀试验箱

Corrosion of metals and alloys — Accelerated testing

involving cyclic exposure to salt mist, dry and wet

conditions

WARNING — This document may involve hazardous materials, operations and equipment. It does

not purport to address all of the safety problems associated with its use. It is the responsibility

of the user of this document to establish appropriate safety and health practices.

1 Scope

This document specifies the apparatus and test procedure to be used in conducting accelerated

corrosion tests for the comparative evaluation of metallic materials with or without permanent

corrosion protection or temporary corrosion protection in salt-contaminated outdoor environments.

The test involves cyclic exposure of the specimens to neutral salt mist, “dry" and “wet" conditions. The

type of test specimen and the exposure period are not specified.

The particular advantages of this test over common accelerated tests such as the neutral salt spray

(NSS) test lie in its ability to better reproduce the corrosion that occurs in outdoor salt-contaminated

environments.

This document is applicable to

—

metals and their alloys,

—

metallic coatings (anodic and cathodic),

—

conversion coatings,

—

anodic oxide coatings, ａnd

—

organic coatings on metallic materials.

NOTE

Methods of test for coatings to determine their resistance, in the presence of scribe marks through

to the substrate, to various cyclic corrosion conditions which include the condensation of water on the test

specimens during periods of humidity are given in ISO 11997-1.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 1514,Paints and varnishes — Standard panels for testing

ISO 2808,Paints and varnishes — Determination of film thickness

ISO 4623-2:2016,Paints and varnishes — Determination of resistance to filiform corrosion — Part 2:

Aluminium substrates

ISO 8044,Corrosion of metals and alloys — Basic terms and definitions

ISO 17872,Paints and varnishes — Guidelines for the introduction of scribe marks through coatings on

metallic panels for corrosion testing

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 8044 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

—

ISO Online browsing platform: available a

reference material

material with known test performance

reference specimen

portion of thereference material () that is to be exposed with the intention to check the reproducibility

ａnd repeatability of the test results for the test cabinet in use

test specimen

specific portion of the samples upon which the testing is to be performed

substitute specimen

specimen made of inert materials (such as plastic or glass) used for the substitute of atest specimen ()

4 Test solution

General

Instructions for the preparation and use of a neutral sodium chloride solution are given in and.

Preparation of the sodium chloride solution

Dissolve a sufficient mass of sodium chloride in distilled or deionized water with a conductivity no

higher than 20 μS/cm at 25 °C ± 2 °C to produce a concentration of 50 g/l ± 5 g/l. The sodium chloride

concentration of the sprayed solution collected shall be 50 g/l ± 5 g/l. The specific gravity range for a

50 g/l ± 5 g/l solution is 1,029 to 1,036 at 25 °C.

The sodium chloride shall not contain a mass fraction of the heavy metals of copper (Cu), nickel (Ni) ａnd

lead (Pb) in total more than 0,005 %. It shall not contain a mass fraction of sodium iodide more than

0,1 % and a mass fraction of total impurities more than 0,5 %, calculated for dry salt.

NOTE

Sodium chloride with anti-caking agents can act as corrosion inhibitors or accelerators. A useful