ISO/TC 156 - Corrosion of metals and alloys

This document specifies the requirements for the external and internal cathodic protection for offshore wind farm structures. It is applicable for structures and appurtenances in contact with seawater or seabed environments. This document addresses: — design and implementation of cathodic protection systems for new steel structures; — assessment of residual life of existing cathodic protection systems; — design and implementation of retrofit cathodic protection systems for improvement of the protection level or for life extension of the protection; — inspection and performance monitoring of cathodic protection systems installed on existing structures, and — guidance on cathodic protection of reinforced concrete structures.

This document specifies performance requirements for cathodic protection of steel in cement-based concrete, in both new and existing structures. It covers building and civil engineering structures, including carbon steel reinforcement and prestressed reinforcement embedded in the concrete. It is applicable to uncoated steel reinforcement and to organic-coated steel reinforcement. It is not applicable to reinforced concrete containing electrically conductive fibres (e.g. carbon or steel). This document applies to steel embedded in atmospherically exposed, buried, immersed and tidal elements of buildings or structures. This document is only applicable to the applications of cathodic protection to steel in concrete which are designed with the intention to, and can be demonstrated to, meet the criteria of protection specified in 8.6. This requires the provision of sufficient performance monitoring systems as specified in 6.3 to all parts of the structure intended to be protected, in order to assess the extent to which the criteria in 8.6 are met. This document does not apply to galvanic anodes or systems applied into patch repairs to reduce the effects of ‘incipient anodes’. This document does also not apply to any form of cathodic protection systems or other electrochemical treatments that either cannot meet the requirements of 8.6 or are not provided with the performance monitoring systems (see 6.3) that are necessary to assess whether the criteria of protection specified in 8.6 are met. NOTE 1 Annex A gives guidance on the principles of cathodic protection and its application to steel in concrete. NOTE 2 This document, while not specifically intended to address cathodic protection of steel in any electrolyte except concrete, can be applied to cathodic protection of steel in other cementitious materials such as are found, for example, in early 20th century steel-framed masonry, brick and terracotta clad buildings. In such applications, additional considerations specific to these structures are required in respect of design, materials and installation of cathodic protection; however, the requirements of this document can be applied to these systems.

This document provides an overview of the corrosivity of disinfectants and corrosion protection when using disinfectants, including an overview of test methods that can be used to determine their corrosivity. This document is generic and applicable to organizations of all sizes in all industries, as well as to families and individuals, and it is intended to assist in determining appropriate health and safety measures regarding the use of disinfectants. The resolution of security issues related to the use of disinfectants is outside the scope of this document.

This document specifies a method for evaluating the aesthetic appearance of stainless steels qualitatively by rating rust and stains formed by atmospheric corrosion. The rust and stains on stainless steels formed by atmospheric corrosion are rated by using 10 photographic standards. This method is especially suitable for evaluating the appearance of specimens and structures made of stainless steels under atmosphere exposure.

This document specifies a test method for particle-free erosion corrosion of metallic materials by use of jet-in-slit which is flow induced corrosion in single phase flowing liquids. The test method can be used for ranking materials performance, selecting candidate materials and testing the effects of corrosion inhibitors.

This document specifies: a) the determination of mass gain; b) the surface inspection of products of zirconium and its alloys when corrosion is tested in water at 360 °C or in steam at or above 400 °C; c) the performance of tests in steam at 10,3 MPa. This document is applicable to wrought products, castings, powder metallurgy products and weld metals. This method has been widely used in the development of new alloys, heat-treating practices and for the evaluation of welding techniques. It is applicable for use in its entirety to the extent specified for a product acceptance test, rather than merely a means of assessing performance in service.

1.1 This document specifies procedures for designing, preparing and using pre-cracked specimens for investigating the susceptibility of metal to stress corrosion cracking (SCC) by means of tests conducted under rising load or rising displacement. Tests conducted under constant load or constant displacement are dealt with in ISO 7539-6. The term “metal” as used in this document includes alloys. 1.2 Because of the need to confine plasticity at the crack tip, pre-cracked specimens are not suitable for the evaluation of thin products such as sheet or wire and are generally used for thicker products including plate, bar, and forgings. They can also be used for parts joined by welding. 1.3 Pre-cracked specimens can be stressed quantitatively with equipment for application of a monotonically increasing load or displacement at the loading points. 1.4 A particular advantage of pre-cracked specimens is that they allow data to be acquired from which critical defect sizes, above which stress corrosion cracking can occur, can be estimated for components of known geometry subjected to known stresses. They also enable rates of stress corrosion crack propagation to be determined. 1.5 A principal advantage of the test is that it takes account of the potential impact of dynamic straining on the threshold for stress corrosion cracking. 1.6 At sufficiently low loading rates, the threshold stress intensity factor for susceptibility to stress corrosion cracking, KISCC, determined by this method can be less than or equal to that obtained by constant load or displacement methods and can be determined more rapidly.

This document specifies a test method for determining the stress corrosion crack (SCC) growth rate of steels and alloys under static-load conditions in high-temperature water, such as the simulated water environment of light water reactors. The crack length of the specimen is monitored by a potential drop method (PDM) during the test in an autoclave. The test method is applicable to stainless steels, nickel base alloys, low alloy steels, carbon steels and other alloys.

This document specifies procedures for the removal of corrosion products formed on metal and alloy corrosion test specimens during their exposure in corrosive environments. For the purpose of this document, the term "metals" refers to pure metals and alloys. The specified procedures are designed to remove all corrosion products without significant removal of base metal. This allows an accurate determination of the mass loss of the metal, which occurred during exposure to the corrosive environment. In some cases, these procedures are also applicable to metal coatings, providing the possible effects from the substrate are considered.

This document specifies the general requirements for control elements in the life cycle of corrosion control engineering. It is applicable to all types of corrosion control engineering programmes.

This document specifies the general requirements for risk assessment in the life cycle of corrosion control engineering. This document is applicable to a risk assessment of all types of corrosion control engineering programmes.

This document specifies the general requirements for control elements in the life cycle of pipeline corrosion control engineering. This document is applicable to all types of pipeline corrosion control engineering programmes.

This document gives guidelines for the corrosion testing of metals and alloys exposed in deep-sea water, including the selection of the test site, components and assembly of the test system, specimen preparation, testing procedure, evaluation after the retrieval from exposure sites and test report. This document is applicable to the general corrosion exposure testing of metals and alloys as well as localized corrosion tests such as stress corrosion cracking (SCC) testing, galvanic corrosion testing and crevice corrosion testing of specimens exposed in deep-sea water. Testing with exposure in deep sea of other materials such as composites and elastomers can also be carried out with reference to these guidelines, but the evaluation of these materials after the retrieval is different from that of metals and alloys. This document does not include the performance testing of sacrificial anodes for cathodic protection in the field of deep sea, which can be conducted using specified testing cells and equipment in the deep-sea exposure. However, this guidance can also provide useful information as reference for conducting performance testing of sacrificial anodes in deep-sea water.

This document specifies the methodology of using multielectrode arrays for the measurement of the corrosion, especially localized corrosion, of metals and alloys. It can be used as a powerful tool for studying the initiation and propagation processes of localized corrosion. It is also a useful tool for long-term corrosion monitoring in the field, especially for localized corrosion, and for obtaining high throughput results for the evaluation of metals with different compositions and/or physical properties in different environments and the screening of a large number of inhibitors. Additionally, the galvanic coupling current and potential distribution of dissimilar metal parings can be assessed by multielectrode arrays. Multielectrode arrays can be implemented in full-immersion, thin-film, spray and alternating wet?dry cycle exposures. This document is not intended to be used for measurements of corrosion caused by a non-electrochemical mechanism.

This document specifies a test method for atmospheric corrosion measurements, using two-electrode electrochemical sensors. It is applicable to measurements of the corrosion rate of uncoupled metal surfaces (i.e. "free" corrosion rate), galvanic corrosion rate, conductance of thin film solutions and barrier properties of organic coatings. It specifies electrochemical sensors that are used with or without organic coatings. The sensors are applicable to corrosion measurements made in laboratory test chambers, outdoor exposure sites and service environments.

This document gives guidelines for the selection of procedures that can be used in the identification and examination of corrosion pits and in the evaluation of pitting corrosion and pit growth rate.

This document specifies procedures for testing the resistance to localized corrosion of Ti alloys fabricated via additive manufacturing (AM) method. This document regulates the electrochemical critical localized corrosion temperature (E-CLCT) of the AM Ti materials for a comparative evaluation of resistance to localized corrosion.

This document specifies a method for the electrochemical measurement of ion transfer resistance of the rust layer formed on weathering steel alloys in order to assess their protective properties against corrosion thereafter[3]. This method uses an electrochemical AC impedance measurement[4][5][6][7][8], together with harmonic analysis, to identify the ion transfer resistance, and a rust thickness measurement to characterize the stability of the protective rust layer in terms of corrosion protection under used environments.

This document specifies methods for determining corrosion rates with standard specimens of metals in indoor atmospheres with low corrosivity. For this direct method of evaluation corrosivity, different sensitive methods can be applied using standard specimens of the following metals: copper, silver, zinc, steel and lead. The values obtained from the measurements are used as classification criteria for the determination of indoor atmospheric corrosivity.

This document establishes a classification of low corrosivity of indoor atmospheres. It specifies the reference metals for which a corrosion attack after a defined exposure period is used for determining corrosivity categories of indoor atmospheres of low corrosivity. It defines corrosivity categories of indoor atmospheres according to corrosion attack on standard specimens. It indicates important parameters of indoor atmospheres that can serve as a basis for an estimation of indoor corrosivity. The selection of a method for the determination of corrosion attack, description of standard specimens, exposure conditions and evaluation are given in ISO 11844-2. The measurement of environmental parameters affecting indoor corrosivity is given in ISO 11844-3.

This document specifies the apparatus, materials, specimen preparation, procedures, results and reports for comparing the corrosion rates of steel reinforcement bars in concrete in simulated marine and coastal environments. This document is not applicable to galvanized steel reinforcement. It gives guidelines for material selection in corrosion design. In order to illustrate the methodology, Annex A provides examples of experimental results.

This document specifies procedures for designing, preparing and using reversed U-bend (RUB) test specimens for investigating the susceptibility of the metal to stress corrosion cracking. The term "metal" as used in this document includes alloys.

This document specifies general principles for carrying out corrosion tests under conditions of constant immersion. Some of these general principles are applicable to other types of corrosion testing. This document does not cover important procedures for stress corrosion testing, such as those given in ISO 7539 (all parts).

This document specifies requirements for the design, installation, positioning, sizing, use and maintenance of coupons for the assessment of the effectiveness of cathodic protection (CP) of buried and immersed metallic structures, such as pipelines, in the case of normal operation as well as AC and DC interference conditions.

This document defines terms relating to corrosion that are widely used in modern science and technology. In addition, some definitions are supplemented with short explanations. NOTE 1 Throughout the document, IUPAC rules for electrode potential signs are applied. The term "metal" is also used to include alloys and other metallic materials. NOTE 2 Terms and definitions related to the inorganic surface treatment of metals are given in ISO 2080.

This document specifies methods for measuring the environmental parameters used to classify the corrosivity of indoor atmospheres on metals and alloys.

This document specifies protection criteria for determining the AC corrosion risk of cathodically protected pipelines. It is applicable to buried cathodically protected pipelines that are influenced by AC traction systems and/or AC power lines. In the presence of AC interference, the protection criteria given in ISO 15589-1 are not sufficient to demonstrate that the steel is being protected against corrosion. This document provides limits, measurement procedures, mitigation measures, and information to deal with long-term AC interference for AC voltages at frequencies between 16,7 Hz and 60 Hz and the evaluation of AC corrosion likelihood. This document deals with the possibility of AC corrosion of metallic pipelines due to AC interferences caused by conductive, inductive or capacitive coupling with AC power systems and the maximum tolerable limits of these interference effects. It takes into account the fact that this is a long-term effect, which occurs during normal operating conditions of the AC power system. This document does not cover the safety issues associated with AC voltages on pipelines. These are covered in national standards and regulations (see, e.g., EN 50443).

This document specifies a method for assessing the resistance of materials or products to a humid atmosphere containing sulfur dioxide. This method is applicable to testing metals and alloys, metallic and non-organic coatings and organic coatings.

This document specifies a method for determining the growth rate of small surface cracks in an aqueous environment (including atmospheric exposure) based on measurement of the change in size of the crack with exposure time. The methodology can be applied to stress corrosion and corrosion fatigue crack propagation. It also describes the varied methodologies for the generation of crack precursors including accelerated generation of single pits. Industries for whom this document is relevant include power generation (including nuclear), oil and gas, aerospace and automotive.

This document specifies a method for the determination of resistance to stress corrosion cracking (SCC) of magnesium alloys intended for use in structural applications (such as magnesium front end, gearbox and clutch housing units, steering column parts, shift actuators, valve covers and housings, brackets and intake manifold blades, electronic devices, power tools and medical equipment). The method allows determination of the resistance to SCC as a function of the chemical composition, the method of manufacture and heat treatment of magnesium alloys. The document is applicable to cast and wrought magnesium alloys in the form of castings, semi-finished products, parts and weldments and covers the method of sampling, the types of specimens, the loading procedure, the type of environment and the interpretation of results. The document allows assessment of the relative performance of materials and products in environments containing chlorides or sulphates, provided that the failure mechanism is not changed, but does not qualify a material or product for service application.

This document specifies procedures for designing, preparing and using precracked specimens for investigating susceptibility to stress corrosion. It gives recommendations for the design, preparation and use of precracked specimens for investigating susceptibility to stress corrosion. Recommendations concerning notched specimens are given in Annex A. The term "metal" as used in this document includes alloys. Because of the need to confine plasticity at the crack tip, precracked specimens are not suitable for the evaluation of thin products, such as sheet or wire, and are generally used for thicker products including plate bar and forgings. They can also be used for parts joined by welding. Precracked specimens can be loaded with equipment for application of a constant load or can incorporate a device to produce a constant displacement at the loading points. Tests conducted under increasing displacement or increasing load are dealt with in ISO 7539-9. A particular advantage of precracked specimens is that they allow data to be acquired, from which critical defect sizes, above which stress corrosion cracking can occur, can be estimated for components of known geometry subjected to known stresses. They also enable rates of stress corrosion crack propagation to be determined. The latter data can be taken into account when monitoring parts containing defects during service.

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.

This document specifies two accelerated corrosion-test procedures, Methods A and B, for the comparative evaluation of metallic materials with or without permanent corrosion protection or temporary corrosion protection in outdoor salt and/or acid rain environments. It also specifies the apparatus used. The two tests involve cyclic exposure of the specimens to acidified salt spray, "dry" and "wet" conditions. The particular advantages of the two tests over conventional accelerated tests, such as the neutral salt spray (NSS) test as specified in ISO 9227 lie in their better ability to reproduce the corrosion that occurs in outdoor salt and/or acid rain environments. They are also useful for evaluating cosmetic corrosion. Method A is applicable to — metals and their alloys, — metallic coatings (cathodic), — anodic oxide coatings, and — organic coatings on metallic materials. Method B is applicable to — steel coated with anodic coatings, and — steel coated with anodic coatings covered with conversion coatings.

ISO 19097-1:2018 specifies accelerated life test method of mixed metal oxide anodes for impressed current cathodic protection used in concrete. The accelerated life test results can be used to compare the durability of the anodes and to evaluate whether the anodes can comply with required specifications of design life expectancy at rated current output. ISO 19097-1:2018 is also applicable to other anode systems that are used as impressed current anodes embedded in concrete with suitably modified apparatus to hold anodes of different geometry.

ISO 19097-2:2018 specifies accelerated life test method of mixed metal oxide anodes for impressed current cathodic protection used in soil or natural waters. The accelerated life test results can be used to compare the durability of the anodes and to evaluate whether the anodes can comply with required specifications of design life expectancy at rated current output.

ISO 11130:2017 specifies a method for assessing the corrosion resistance of metals by an alternate immersion test in salt solution, with or without applied stress. The test is particularly suitable for quality control during the manufacture of metals including aluminium alloys and ferrous materials, and also for assessment purposes during alloy development. Depending upon the chemical composition of the test solution, the test can be used to simulate the corrosive effects of marine splash zones, de-icing fluids and acid salt environments. The term "metal" as used in this document includes metallic materials with or without corrosion protection. ISO 11130:2017 is applicable to - metals and their alloys, - certain metallic coatings (anodic and cathodic with respect to the substrate), - certain conversion coatings, - certain anodic oxide coating, and - organic coatings on metals.

ISO 12473 covers the general principles of cathodic protection when applied in seawater, brackish waters and marine mud. It is intended to be an introduction, to provide a link between the theoretical aspects and the practical applications, and to constitute a support to the other standards devoted to cathodic protection of steel structures in seawater. ISO 12473 specifies the criteria required for cathodic protection. It provides recommendations and information on reference electrodes, design considerations and prevention of the secondary effects of cathodic protection. The practical applications of cathodic protection in seawater are covered by the following standards: - EN 12495, Cathodic protection for fixed steel offshore structures; - ISO 13174, Cathodic protection of harbour installations (ISO 13174); - EN 12496, Galvanic anodes for cathodic protection in seawater and saline mud; - EN 13173, Cathodic protection for steel offshore floating structures; - EN 16222, Cathodic protection of ship hulls; - EN 12474, Cathodic protection of submarine pipelines; - ISO 15589‑2, Petroleum, petrochemical and natural gas industries ? Cathodic protection of pipeline transportation systems ? Part 2: Offshore pipelines. For cathodic protection of steel reinforced concrete whether exposed to seawater or to the atmosphere, ISO 12696 applies.

ISO 19280:2017 specifies a methodology for ranking the crevice corrosion resistance of stainless steels and related alloys when exposed to oxidizing chloride solution. This document allows the measurement of critical crevice temperatures of tube/rod type specimens equal to those of plate type ones made up of the same material by chemical initiation of crevice corrosion, but not by the electrochemical method of ISO 18070. The test method in this document defines the apparatus and the procedure used to measure the temperature of crevice corrosion initiated in pipes and tubes using cylindrical specimens. This method has also been proved to apply to plate type specimens.

ISO 15257:2017 defines five levels of competence (detailed in Clause 4) for persons working in the field of cathodic protection (CP), including survey, design, installation, testing, maintenance and advancing the science of cathodic protection. It specifies a framework for establishing these competence levels and their minimum requirements. Competence levels apply to each of the following application sectors: - on-land metallic structures; - marine metallic structures; - reinforced concrete structures; inner surfaces of metallic structures containing an electrolyte. These application sectors are detailed in Clause 5. ISO 15257:2017 specifies the requirements to be used for establishing a certification scheme as defined in ISO/IEC 17024. It is not mandatory to apply all of the levels and/or application sectors. This certification scheme is detailed in Annexes A, B and C.

ISO 3651-3:2017 specifies the determination of the intergranular corrosion susceptibility of low-Cr [less than 16 % Cr, less than 0,3 % Ni, less than 0,3 % Ti and less than 0,3 % Nb, less than 0,3 % (Ti + Atomic weight ratio Nb)] ferritic stainless steels in the 0,5 % sulfuric acid/copper sulfate test. It also specifies the purposes which may be assigned to the test. The method is applicable to stainless steels supplied in the form of rolled sheets and welded tubes and intended for use in a mildly oxidizing acid medium. It is important to note that the result of the corrosion test is only strictly valid for the corrosive medium used in the test. It constitutes a basis for estimating the resistance to intergranular corrosion but cannot be used to check resistance to other forms of corrosion (general corrosion, pitting, stress corrosion, etc.). It is important for the user to adapt the specified corrosion test where steels are used. This test is, in no case, considered as an absolute criterion of the quality of the metal.

ISO 6509-2:2017 specifies assessment criteria and provides guidance related to the corrosion type dezincification for the selection of copper alloys with a mass fraction of zinc of more than 15 %, exposed to fresh, saline waters or drinking water. The assessment criteria are based on the exposure tests in ISO 6509‑1. The materials can be in the form of a semi-finished product or in the form of a final product (fittings, valves, etc.). ISO 6509-2:2017 is not applicable to complex products like flow-meters or pump-parts. In addition, other properties of the material might need to be taken into account for the intended application. This document is not intended to validate dezincification in case of failure in the application.

ISO 9227:2017 specifies the apparatus, the reagents and the procedure to be used in conducting the neutral salt spray (NSS), acetic acid salt spray (AASS) and copper-accelerated acetic acid salt spray (CASS) tests for assessment of the corrosion resistance of metallic materials, with or without permanent or temporary corrosion protection. It also describes the method employed to evaluate the corrosivity of the test cabinet environment. It does not specify the dimensions or types of test specimens, the exposure period to be used for a particular product, or the interpretation of results. Such details are provided in the appropriate product specifications. The salt spray tests are particularly useful for detecting discontinuities, such as pores and other defects, in certain metallic, organic, anodic oxide and conversion coatings. The neutral salt spray (NSS) test particularly applies to - metals and their alloys, - metallic coatings (anodic and cathodic), - conversion coatings, - anodic oxide coatings, and - organic coatings on metallic materials. The acetic acid salt spray (AASS) test is especially useful for testing decorative coatings of copper + nickel + chromium, or nickel + chromium. It has also been found suitable for testing anodic and organic coatings on aluminium. The copper-accelerated acetic acid salt spray (CASS) test is useful for testing decorative coatings of copper + nickel + chromium, or nickel + chromium. It has also been found suitable for testing anodic and organic coatings on aluminium. The salt spray methods are all suitable for checking that the quality of a metallic material, with or without corrosion protection, is maintained. They are not intended to be used for comparative testing as a means of ranking different materials relative to each other with respect to corrosion resistance or as means of predicting long-term corrosion resistance of the tested material.

ISO/TR 16203:2016 provides information on the erosion corrosion test of materials in single-phase flowing liquids and guidance for selection of test methods.

ISO 21207:2015 defines two accelerated corrosion test methods to be used in assessing the corrosion resistance of products with metals in environments where there is a significant influence of chloride ions, mainly as sodium chloride from a marine source or by winter road de-icing salt, and of corrosion-promoting gases from industrial or traffic air pollution. ISO 21207:2015 specifies both the test apparatus and test procedures to be used in executing the accelerated corrosion tests. The methods are especially suitable for assessing the corrosion resistance of sensitive products with metals, e.g. electronic components, used in traffic and industrial environments.

ISO 18089:2015 describes the procedure for determining the critical crevice temperature (CCT) for stainless steels under potentiostatic control. The principal advantage of the test is the rapidity with which the CCT can be measured in a single test procedure. The CCT, as determined in this International Standard, can be used as a relative index of performance, for example, to compare the relative performance of different grades of stainless steel. The test described in this International Standard is not intended to determine the temperature at which crevice corrosion will occur in service. This method is not intended for materials with critical pitting temperature (CPT) values below 20 °C measured in accordance with ISO 17864, when measured in the same test solution and at the same potential

ISO 18070:2015 specifies a crevice forming technique and crevice former which are intended to be used for crevice corrosion testing of flat specimens or tubes of stainless steels, in corrosive solutions. This International Standard specifies no information concerning how the crevice corrosion testing shall be performed and how the attack shall be evaluated. The crevice former specified in this International Standard can be used for electrochemical measurements, if the specimens are designed for electrical connections.

ISO 16540:2015 provides guidelines for the use of four-point bend testing to evaluate the resistance of metals including carbon steel, low alloy steels, and corrosion resistant alloys (CRAs) to stress corrosion cracking. The method gives guidance on testing of both parent plate and welds and includes procedures for metals that have no distinct yield point in their stress-strain behaviour as well as metals with a distinct yield point. The emphasis in this International Standard is on the generic methodology of the four-point bend test. Service application will be varied and the relevant industry standard is to be consulted where appropriate.

ISO 17918:2015 specifies procedures of on-site detection and evaluation in order to determine the effects of material deterioration such as material loss from the components and structures that are sensitive to selective corrosion in industrial facilities, including nuclear power plants. The methodology involves visual inspection and hardness measurements in situ complemented by sample removal. These procedures include (a) representative sampling of components sensitive to selective corrosion, (b) the visual inspection, and (c) the hardness test, respectively. For an exact analysis, additional laboratory testing is recommended. The methodology is most applicable to grey cast iron and copper alloy with more than 15 % zinc. Extension to other alloys requires supportive evidence of validation. Assessment criteria orientated to the nuclear power plant application during the past five years before the end of extended operation define the necessity for further engineering evaluation and action like, for example, further sampling, higher frequency of inspection, and component repair or exchange. This specification is not applicable for components used where the representative sampling of surfaces in contact to the fluid is not detectable optically or detected with the portable hardness tester. Also, in case of non-representative component selection like in HVAC or building service application, this specification is not applicable. For components not used in nuclear power plant, the assessment criteria have to be agreed by the parties. Assessment criteria of hardness test alone is not applicable to the evaluation of structural integrity of Al-bronze, NAB, and Cu-Ni.

ISO 17093:2015 is intended to assist in corrosion testing by electrochemical noise measurement. It covers test procedures and analysis methods for reliable measurement of electrochemical noise for both uncoated and organically coated metal.

ISO 18069:2015 specifies the measurements of the corrosion rate of uniform corrosion for stainless steels and nickel based alloys in the intended liquids and the ability for the material to passivate after activation. This method is intended to be used for estimation of the uniform corrosion rate in liquids, under atmospheric conditions, for the chemical industry under specific environmental conditions and not as a qualification test. It can also be used to determine iso-corrosion diagrams and at which temperature the corrosion rate exceeds 0,1 mm/a. ISO 18069:2015 is not intended for excessive corrosion rates above 1 mm/a since an even higher corrosion rate indicates that the stainless steel is not suitable in the application. Nor is it intended to be used for solutions containing halides, especially chlorides, since these might cause localized corrosion.