AMPP Store - Products tagged with 'soluble salts'

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Critical Review of International Standards on Soluble Salts Measurement Methods

Product Number: 51324-20851-SG

Author: Sophia Xiaoxia Zhu; Benjamin T. A. Chang

Publication Date: 2024

$40.00

It is well known that the residual salts on steel substrates have detrimental effects on the coating performance. There are several international standards on the measurement of residual salts. The most widely recognized ones are ISO 8502-6 and 8502-9. ISO 8502-6 specifies the soluble salts extraction procedures and ISO 8502-9 specifies the calculation of the soluble NaCl salt. The standards use 3 ml deionized (DI) water in 10 minutes dwell time to extract the soluble salts to measure with a potable conductivity meter. The measured conductivity reading in µS/cm is multiplied by 1.2 to convert into total (NaCl) salts in mg/m2. The ISO standards assume the extracted salt solution containing only Na+ and Cl- ions and use a simple analytical calculation to convert the conductivity to the total NaCl salt concentration on the contaminated steel surface. In fact, in addition to Na+ and Cl- ions, Fe+2, OH- ions are also in the extracted salt solution contributing to the conductivity reading, but not considered in the total salt calculation. The ISO standards on the total (NaCl) salt measurement are oversimplified that leads to inaccurate estimation of the residual salts. The chloride ions in aqueous condition can cause micro-pits on the carbon steel surface. The pit density and depth are related to the salt levels and corrosion reaction time. During the salt measurement, the DI water can not readily migrate to the micro-pits to extract salts, and the salt extraction efficiency depends on the corrosion severity. In this work we have investigated the salt extraction on doped salted steel panels with five known amounts of NaCl salt. We also used a chloride electrode to measure the chloride ion concentration. The test results showed that the salt extraction efficiency depends on the severity of the pitting corrosion. Based on the chloride level, the extraction efficiency is 90% at low salt content and 50-66% at higher salt content on the grit blasted panels using Bresle patch method. It is recommended to use the residual chloride concentration in the coating specifications as the acceptance criterion, not the total NaCl salt level. More research is to be done to investigate the residual chloride measurements to give the international coating community a more reliable test method in the field.

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NACE SP0716-2023, Soluble Salt Testing Frequency and Locations on Previously Coated Surfaces

Product Number: NACE SP0716-2023

Publication Date: 2023

$109.00

Asset owners, engineers, consultants, coating contractors, inspectors, and others are specifying allowable levels of surface soluble salts to prevent premature coating failures. The purpose of this standard is to provide guidance about the number of and locations for soluble salt tests on steel surfaces.

This standard establishes siting and frequency requirements for soluble salt testing before the application of a subsequent coating system to previously coated substrates and replacement substrate material. It does not include allowable limits of soluble salts, which are typically addressed by the procurement documents or the coating manufacturer’s documentation.

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NACE TR43114-2022, Nonvisible Contaminants on Railcar Surfaces

Product Number: NACE TR43114-2022

Publication Date: 2022

$109.00

The purpose of this technical committee report is to increase railcar industry awareness of nonvisible surface contamination (NVSC), its impact, and its removal before coating application to the railcar. For the purpose of this report, NVSC is defined as any substance that may affect coating performance and does not leave a visible deposit on a bare or previously coated carbon steel surface. This report discusses how NVSC may have a harmful effect on the performance and lifespan of a coating system. This report also identifies types of NVSC and methods for its removal.

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Soluble Salt Contamination: Testing and Cleaning before Coating

Product Number: 51324-20827-SG

Author: Cortney Chalifoux; Alec Kraynak

Publication Date: 2024

$40.00

This paper focuses on the often-overlooked issue of soluble salt contamination testing and removal during surface preparation prior to coating application. Soluble salts, including chlorides, sulfates, and nitrates, left on the surface prior to coating application can lead to osmotic blistering, corrosion, and coating failures. Several standards provide methods to test for soluble salts. However, there is no industry consensus on acceptable contamination levels given the diversity of coating systems and environments. This paper serves as a guide intended to shed light on the specific issue of soluble salt contamination, particularly on carbon steel surfaces. By addressing the nuances and challenges posed by soluble salt contaminants, this paper aims to equip engineers and professionals in the field with the knowledge and tools necessary to navigate the complexities of surface preparation and ensure the integrity and longevity of coating systems on carbon steel surfaces.

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Surface Soluble Salts Impact on Protective Coating Performance

Product Number: 51220-277-SG

Author: Andrew Recker

Publication Date: 2020

$20.00

To address questions and concerns in the protective and marine coatings market, new laboratory data has been generated regarding corrosion rates and mechanisms that will help eliminate some of the assumptions regarding the role of soluble salts. These assumptions include soluble salt types such as chloride, sulfate, and nitrate along with the resulting conjugate corrosion products.

Products tagged with 'soluble salts'

Critical Review of International Standards on Soluble Salts Measurement Methods

NACE SP0716-2023, Soluble Salt Testing Frequency and Locations on Previously Coated Surfaces

NACE TR43114-2022, Nonvisible Contaminants on Railcar Surfaces

Soluble Salt Contamination: Testing and Cleaning before Coating

Surface Soluble Salts Impact on Protective Coating Performance

Association for Materials Protection and Performance