ASTM D5723-95(2019)

Standard Practice for Determination of Chromium Treatment Weight on Metal Substrates by X-Ray Fluorescence

SIGNIFICANCE AND USE
3.1 The procedure described in this practice is designed to provide a method by which the coating weight of chromium treatments on metal substrates may be determined.  
3.2 This procedure is applicable for determination of the total coating weight and the chromium coating weight of a chromium-containing treatment.
SCOPE
1.1 This practice covers the use of X-ray fluorescence (XRF) techniques for determination of the coating weight of chromium treatments on metal substrates. These techniques are applicable for determination of the coating weight as chromium or total coating weight of a chromium-containing treatment, or both, on a variety of metal substrates.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Nov-2019
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.53 - Coil Coated Metal

Relations

• Replaces: ASTM D5723-95(2015) - Standard Practice for Determination of Chromium Treatment Weight on Metal Substrates by X-Ray Fluorescence
• Effective Date: 01-Dec-2019
• Referred By: ASTM D3794-22 - Standard Guide for Testing Coil Coatings
• Effective Date: 01-Dec-2019
• Referred By: ASTM D6492-99(2022) - Standard Practice for Detection of Hexavalent Chromium On Zinc and Zinc/Aluminum Alloy Coated Steel
• Effective Date: 01-Dec-2019

Overview

ASTM D5723-95(2019): Standard Practice for Determination of Chromium Treatment Weight on Metal Substrates by X-Ray Fluorescence delivers guidance for using X-ray fluorescence (XRF) techniques to accurately measure the coating weight of chromium-containing treatments on various metal substrates. Developed by ASTM International, this standard offers a consistent, quantitative approach for manufacturers, laboratories, and quality assurance teams needing to determine both the total coating weight and the specific chromium content on treated metal surfaces. Adhering to international principles, ASTM D5723 aligns with practices established under World Trade Organization Technical Barriers to Trade (TBT) Committee decisions, ensuring global applicability.

Key Topics

• X-Ray Fluorescence Methodology: The standard outlines how XRF detects and measures the secondary radiation emitted from chromium treatments, providing a non-destructive and reliable means for coating weight analysis.
• Calibration and Instrumentation: Emphasis is placed on using calibrated instruments and standards tailored to specific substrate and treatment combinations. The use of primary standards and calibration curves is critical for accurate measurement.
• Test Specimen Preparation: Guidelines ensure specimens are flat, free of contaminants, and appropriately sized to fit the measuring instrument.
• Calculation Approach: The coating weight calculation is based on the difference in XRF emission counts between blank (untreated) and treated specimens, using a conversion factor supplied by the treatment provider.
• Safety and Compliance: Users are responsible for implementing appropriate safety, health, and environmental practices in accordance with regulations.

Applications

The procedures detailed in ASTM D5723-95(2019) are widely utilized in sectors where metal substrates receive chromium-containing surface treatments. Key applications include:

• Manufacturing Quality Control: Ensuring coatings are applied uniformly and meet specified weight requirements for corrosion resistance and functionality.
• Metallurgical Laboratories: Providing standardized methods for routine analysis of metal samples treated with chromium compounds.
• Automotive and Aerospace Industries: Monitoring chromium treatment thicknesses on structural and decorative components to support durability and compliance.
• Coil Coating Operations: Enabling efficient, non-destructive testing of sheet metal products in continuous production environments.
• Coating Suppliers: Assisting in the verification of Chromium treatment processes and ensuring consistent application across multiple production batches.

Consistent application of this standard supports product performance, regulatory compliance, and process optimization by delivering reliable and repeatable measurements.

Related Standards

• ASTM B568 - Standard Test Method for Measurement of Coating Thickness by X-Ray Spectrometry, which outlines broader applications of X-ray techniques for coatings beyond chromium.
• ASTM D2093 - Standard Practice for Preparation of Surfaces of Plastics Prior to Adhesive Bonding, relevant for surface preparation protocols.
• ISO 3497 - Metallic coatings - Measurement of coating thickness - X-ray spectrometric methods, offering international context for similar measurement techniques.
• ASTM D1186 - Standard Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous Base, helpful for comparative coating weight analysis.

By referencing ASTM D5723-95(2019), organizations enhance accuracy in chromium treatment weight determination, ensuring adherence to industry best practices and improving product quality on a global scale.

Keywords: chromium coating weight, X-ray fluorescence, metal substrate, ASTM D5723, coating thickness, non-destructive testing, quality control, calibration standards, surface treatment analysis.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5723 − 95 (Reapproved 2019)
Standard Practice for
Determination of Chromium Treatment Weight on Metal
Substrates by X-Ray Fluorescence
This standard is issued under the fixed designation D5723; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.3.1 A relationship exists between the treatment coating
weight and secondary radiation intensity. This relationship is
1.1 This practice covers the use of X-ray fluorescence
usually linear within the desired coating weights of the
(XRF) techniques for determination of the coating weight of
chromium treatments on metal substrates. The measurements
chromium treatments on metal substrates.These techniques are
are based on primary standards of known coating weights and
applicable for determination of the coating weight as chro-
instrument calibration that correlates the secondary radiation
mium or total coating weight of a chromium-containing
intensity with the coating weight quantitatively.
treatment, or both, on a variety of metal substrates.
2.3.2 The coating weight is determined by measurement of
1.2 This standard does not purport to address all of the
the fluorescent X rays of the coating. The detection system is
safety concerns, if any, associated with its use. It is the
set to count the number of X rays in an energy region that is
responsibility of the user of this standard to establish appro-
characteristic of X rays from the element of interest. The
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. element of interest in this practice is chromium.
1.3 This international standard was developed in accor-
2.3.3 If a linear relationship exists, the coating weight and
dance with internationally recognized principles on standard-
number of counts of X rays of a chromium treatment on a
ization established in the Decision on Principles for the
particular substrate can be expressed by a conversion factor
Development of International Standards, Guides and Recom-
that represents the number of counts for a particular coating
mendations issued by the World Trade Organization Technical
weight unit/unit area. This is usually expressed in mg/ft or
Barriers to Trade (TBT) Committee. 2
mg/m of chromium or total coating weight.
2.3.4 The exact relationship between the measured number
2. Summary of Practice
of counts and corresponding coating weight must be estab-
2.1 Excitation—The measurement of chromium treatment
lished for each individual combination of substrate and
coating weights by XRF methods is based on the combined
chromium-containing treatment. Usually determined by the
interaction of the chromium coating and substrate with an
treatment supplier, this relationship is established by using
intense beam of primary radiation. Since each element fluo-
primary standards having known amounts of the same treat-
resces at an energy characteristic of the particular element, this
ment applied to the same substrate composition as the speci-
interactionresultsinthegenerationofXraysofdefinedenergy.
mens to be measured.
The primary radiation may be generated by an X-ray tube or
2.3.5 Some X-ray apparatus have a data handling system
derive from a radioisotope.
whereby a coating weight versus X-ray counts curve may be
2.2 Detection—The secondary beam (fluorescent X rays of
established within the system for the direct readout of coating
the elements and scattered radiation) is read by a detector that
weight. If such apparatus does not permit the entry of a
can discriminate between the energy levels of fluorescing
conversion factor as described in 2.3.3, it is calibrated using a
radiations in the secondary beam. The detection system in-
bare, untreated specimen and a minimum of three specimens
cludes the radiation detector with electronics for pulse ampli-
with known coating weights of the treatment and substrate
fication and pulse counting.
combination of interest. The coating weight to be measured
2.3 Basic Principle:
mustbewithintherangeoftheseknowncoatingweights.More
than three known specimens must be used if the relationship of
1 X-ray counts to coating weight is not linear over the range to
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications and is the direct responsibility of
be measured. The treatment supplier should be consulted for
Subcommittee D01.53 on Coil Coated Metal.
recommendations for establishing the curve in the instrument
Current edition approved Dec. 1, 2019. Published December 2019. Originally
for the particular treatment and substrate combination of
approved in 1995. Last previous edition approved in 2015 as D5723 – 95 (2015).
DOI: 10.1520/D5723-95R19. interest.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5723 − 95 (2019)
3. Significance and Use 5.4 The coated area of the specimen must be larger than the
measuring area.
3.1 The procedure described in this practice is designed to
provide a method by which the coating weight of chromium
6. Procedure
treatments on metal substrates may be determined.
6.1 Operate the instrument in accordance with the manufac-
3.2 This procedure is applicable for determination of the
turer’s instructions.
total coating weight and the chromium coating weight of a
chromium-containing treatment.
6.2 Set the instrument settings as follows:
Dial and Arm Chromium Position
4. Apparatus and Materials
Seconds indicator per treatment supplier
Multiplier switch per treatment supplier
4.1 Measuring Instrument, which is capable of determining
Response switch per treatment supplier
the coating weights of chromium-containing treatments on
Range per treatment supplier
metal substrates by X-ray fluorescence is required. The treat-
Milliamps adjust for calibration of output per treatment
...