ASTM B858-06(2018)

Standard Test Method for Ammonia Vapor Test for Determining Susceptibility to Stress Corrosion Cracking in Copper Alloys

SIGNIFICANCE AND USE
5.1 This test method is an accelerated test to determine if a copper alloy product will be susceptible to stress-corrosion cracking when exposed to a particular atmospheric condition during service with the appropriate risk level—see Annex A1.  
5.1.1 This test method is generally intended to determine if a copper alloy product will crack because of internal stresses when subjected to the test, and is not intended for testing assemblies under applied stress. If used for this purpose, it shall be for information only and not a cause for rejection of the assembly, its component parts, or the original mill product.
SCOPE
1.1 This test method describes a procedure to determine the presence of residual stresses in wrought copper alloy products that may lead to stress corrosion cracking. An ammonia vapor atmosphere is used as an accelerated test.  
1.2 This test method is only suitable for products fabricated from copper alloys that are known to be susceptible to stress corrosion cracking in ammonia vapor atmospheres. It is intended to create an environmental condition of reproducible severity.
Note 1: It is well known that the critical step in the cracking mechanism is the development of an environment in the condensate film that occurs on the surface of the test specimen, and is rich in copper complex ions.  
1.3 The severity of this test method depends upon the pH of the corrosive solution. In Annex A1 are given four different atmospheres to which the product may be exposed, and the appropriate pH of the solution to be used for the test, depending on the risk level associated with the intended application.  
1.3.1 The appropriate pH value for the test shall be specified in the product specification, or as per established agreement between the supplier and purchaser, with respect to the alloy and its intended application.  
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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.  
1.6 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: 28-Feb-2018
• ICS: 77.120.30 - Copper and copper alloys
• Technical Committee: B05 - Copper and Copper Alloys
• Drafting Committee: B05.06 - Methods of Test

Relations

• Replaces: ASTM B858-06(2012) - Standard Test Method for Ammonia Vapor Test for Determining Susceptibility to Stress Corrosion Cracking in Copper Alloys
• Effective Date: 01-Mar-2018
• Refers: ASTM B846-19a - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Aug-2019
• Refers: ASTM B846-19 - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Jan-2019
• Refers: ASTM B154-12e1 - Standard Test Method for Mercurous Nitrate Test for Copper Alloys
• Effective Date: 01-Oct-2012
• Refers: ASTM B154-12 - Standard Test Method for Mercurous Nitrate Test for Copper Alloys
• Effective Date: 01-Oct-2012
• Refers: ASTM B846-11a - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Jun-2011
• Refers: ASTM B846-11 - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Jan-2011
• Refers: ASTM B846-09a - Standard Terminology for Copper and Copper Alloys
• Effective Date: 15-Nov-2009
• Refers: ASTM B846-09 - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Nov-2009
• Refers: ASTM B846-06a - Standard Terminology for Copper and Copper Alloys
• Effective Date: 15-Nov-2006
• Refers: ASTM B846-06 - Standard Terminology for Copper and Copper Alloys
• Effective Date: 15-May-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM B846-05 - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Nov-2005
• Refers: ASTM B154-05 - Standard Test Method for Mercurous Nitrate Test for Copper Alloys
• Effective Date: 01-Oct-2005
• Refers: ASTM B154-01 - Standard Test Method for Mercurous Nitrate Test for Copper and Copper Alloys
• Effective Date: 10-Oct-2001

Overview

ASTM B858-06(2018): Standard Test Method for Ammonia Vapor Test for Determining Susceptibility to Stress Corrosion Cracking in Copper Alloys is a globally recognized test method developed by ASTM International. This standard establishes procedures to assess the susceptibility of wrought copper alloy products to stress corrosion cracking (SCC) in ammonia vapor atmospheres. By simulating an accelerated environment, it helps industry professionals identify the presence of residual stresses that could lead to cracking during service.

The ammonia vapor test as defined in ASTM B858 is valuable for quality assurance, ensuring copper alloys used in critical applications are resistant to environmental cracking, and supports informed decisions in both manufacturing and procurement.

Key Topics

• Purpose of the Test Method: Offers an accelerated assessment for SCC susceptibility in copper alloys, especially where residual internal stresses may compromise product integrity.
• Applicability: Designed for copper alloys known to be vulnerable to SCC in ammonia-rich environments. Not intended for assemblies subjected to externally applied stresses unless for informational purposes.
• Environmental Conditions: Utilizes ammonia vapor with controlled pH levels to replicate corrosive service conditions of varying severity, aligned with the intended application’s risk profile.
• Test Parameters:
  • Solution pH specification based on risk level
  • Exposure time (24 hours)
  • Controlled temperature (20-30°C, typically 25°C)
• Specimen Preparation: Details on cleaning, degreasing, and dimensional requirements for accurate, reproducible testing.
• Result Evaluation: Post-test inspection involves visual and, if necessary, metallographic examination for the presence of cracks.

Applications

The ASTM B858 ammonia vapor test is instrumental across several sectors that utilize copper alloys, including:

• Plumbing and Water Distribution: Helps ensure pipes and fittings maintain mechanical integrity in environments prone to ammonia exposure.
• Electrical and Electronic Components: Verifies the durability of connectors and conductors susceptible to stress corrosion in condensed environments.
• HVAC and Industrial Systems: Assures copper alloy components in heating, ventilation, and cooling systems resist cracking over prolonged operational exposure to ammonia.
• Marine and Agricultural Equipment: Critical where ammonia-containing environments or external pollutants may accelerate corrosion.
• Quality Control and Procurement: Used as a screening tool during manufacturing, incoming inspection, or specification compliance for copper alloy parts intended for use in potentially aggressive service atmospheres.

By utilizing ASTM B858, manufacturers and end-users can detect potential failure mechanisms early, reduce warranty claims, and ensure compliance with safety and durability requirements.

Related Standards

Several important standards relate to or complement ASTM B858:

• ASTM B154 - Standard Test Method for Mercurous Nitrate Test for Copper Alloys: Another accelerated corrosion test, referenced for comparison but using a different corrosive agent.
• ASTM B846 - Terminology for Copper and Copper Alloys: Provides definitions and terminology supporting interpretation of results.
• ASTM D1193 - Specification for Reagent Water: Specifies the water quality required for making test solutions.
• International Guidance: Developed in accordance with WTO technical barriers to trade (TBT) principles, ensuring compatibility with global regulations.

Keywords: ammonia vapor test, ASTM B858, copper alloys, stress corrosion cracking, residual stress, accelerated testing, corrosion resistance, product specification compliance.

By following ASTM B858, industry professionals gain a reliable method for evaluating the corrosion behavior of copper alloys under ammonia vapor exposure, leading to safer and more robust products.

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: B858 − 06 (Reapproved 2018)
Standard Test Method for
Ammonia Vapor Test for Determining Susceptibility to
Stress Corrosion Cracking in Copper Alloys
This standard is issued under the fixed designation B858; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This test method describes a procedure to determine the
Barriers to Trade (TBT) Committee.
presence of residual stresses in wrought copper alloy products
that may lead to stress corrosion cracking.An ammonia vapor
2. Referenced Documents
atmosphere is used as an accelerated test.
2.1 ASTM Standards:
1.2 This test method is only suitable for products fabricated
B154Test Method for Mercurous Nitrate Test for Copper
from copper alloys that are known to be susceptible to stress
Alloys
corrosion cracking in ammonia vapor atmospheres. It is in-
B846Terminology for Copper and Copper Alloys
tended to create an environmental condition of reproducible
D1193Specification for Reagent Water
severity.
NOTE 1—It is well known that the critical step in the cracking
3. Terminology
mechanism is the development of an environment in the condensate film
3.1 For definitions of terms related to copper and copper
that occurs on the surface of the test specimen, and is rich in copper
complex ions. alloys, refer to Terminology B846.
1.3 TheseverityofthistestmethoddependsuponthepHof 3.2 Definitions:
the corrosive solution. In Annex A1 are given four different
3.2.1 applied stress, n—stress in a body as a result of
atmospheres to which the product may be exposed, and the application of an external load.
appropriate pH of the solution to be used for the test,
4. Summary of Test Method
depending on the risk level associated with the intended
application.
4.1 The prepared test specimen is placed in a closed
1.3.1 TheappropriatepHvalueforthetestshallbespecified
container and exposed to ammonia vapor with a specific pH at
in the product specification, or as per established agreement
ambient temperature for 24 h. Upon removal from the test
between the supplier and purchaser, with respect to the alloy
atmosphere, the test specimen is examined for the presence of
and its intended application.
cracks.
1.4 Units—The values stated in SI units are to be regarded
5. Significance and Use
asstandard.Nootherunitsofmeasurementareincludedinthis
standard.
5.1 This test method is an accelerated test to determine if a
1.5 This standard does not purport to address all of the copper alloy product will be susceptible to stress-corrosion
safety concerns, if any, associated with its use. It is the cracking when exposed to a particular atmospheric condition
responsibility of the user of this standard to establish appro- during service with the appropriate risk level—see AnnexA1.
priate safety, health, and environmental practices and deter- 5.1.1 This test method is generally intended to determine if
mine the applicability of regulatory limitations prior to use. a copper alloy product will crack because of internal stresses
1.6 This international standard was developed in accor- when subjected to the test, and is not intended for testing
dance with internationally recognized principles on standard- assembliesunderappliedstress.Ifusedforthispurpose,itshall
ization established in the Decision on Principles for the be for information only and not a cause for rejection of the
assembly, its component parts, or the original mill product.
This test method is under the jurisdiction ofASTM Committee B05 on Copper
and Copper Alloys and is the direct responsibility of Subcommittee B05.06 on
Methods of Test. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved March 1, 2018. Published March 2018. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2012 as B858 – 06 (2012). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/B0858-06R18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B858 − 06 (2018)
6. Apparatus cleaning test pieces after testing, a small amount of hydrogen
peroxide solution may be added to the pickling solution (for
6.1 pH meter.
example, 20 to 30 mL of hydrogen peroxide solution per litre
6.2 Closed vessel, such as a desiccator.
of pickling solution).
6.3 Equipment for examining test pieces at 10× to 15×
9. Test Specimen Preparation
magnification.
9.1 The test specimen size shall be prescribed in the
7. Reagents and Materials
specification of the product or part being tested. In the event
7.1 Purity of Reagents—Reagent grade chemicals shall be that a test specimen size is not prescribed in a given rod, wire,
used in all tests. Unless otherwise indicated, it is intended that or tube specification, a full cross section having a minimum
length of 152 mm shall be tested.
all reagents conform to the specifications of the Committee on
Analytical Reagents of theAmerican Chemical Society where
9.2 The presence of burrs on the test specimen may con-
such specifications are available. Other grades may be used,
tribute to acceleration of stress corrosion cracking if not
provided it is first ascertained that the reagent is of sufficiently
removed before the ammonia vapor test. The burrs shall be
high purity to permit its use without lessening the accuracy of
removed by fine file or abrasive paper to facilitate this test.
the determination.
9.3 Degrease the test specimen using the clean organic
7.2 Purity of Water—Unless otherwise indicated, references
solvent or alkaline solution.
to water shall be understood to mean reagent water as defined
9.4 After degreasing, clean the test piece in the pickling
by Type IV or better, of Specification D1193.
solution and immediately thereafter thoroughly rinse it, first in
7.3 Ammonium Chloride Solution (4N)—Dissolve 107 g of
cold running water, then in hot water, and finally, completely
ammonium chloride (NH Cl) in water and dilute to 500 mL.
dry it in a stream of warm air.
Store the solution in a closed vessel.
10. Test Procedure
7.4 Hydrogen Peroxide (H O ), 30 to 35% technical grade.
2 2
(Warning—Hydrogen peroxide in high concentrations can 10.1 Allow the dry test piece to reach the exposure tem-
cause severe skin burns. Use of proper safety equipment is
perature specified below, and transfer it immediately to the
advised.) closedvessel(see6.2)atthesametemperature,andcontaining
thefreshlypreparedtestsolutionatthespecifiedpHvalue(see
7.5 Sodium Hydroxide Solution (300 to 500 g/L)—Dissolve
8.1).
300 to 500 g o
...