ASTM B850-98(2022)

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: B850 − 98 (Reapproved 2022)
Standard Guide for
Post-Coating Treatments of Steel for Reducing the Risk of
Hydrogen Embrittlement
This standard is issued under the fixed designation B850; 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.
INTRODUCTION
When atomic hydrogen enters steel, it can cause a loss of ductility, load carrying ability, or cracking
(usually as submicroscopic cracks), as well as catastrophic brittle failures at applied stresses well
below the yield strength or even the normal design strength for the alloys. This phenomenon often
occurs in alloys that show no significant loss in ductility, when measured by conventional tensile tests,
and is referred to frequently as hydrogen-induced delayed brittle failure, hydrogen stress cracking, or
hydrogen embrittlement. The hydrogen can be introduced during cleaning, pickling, phosphating,
electroplating, autocatalytic processes, porcelain enameling, and in the service environment as a result
of cathodic protection reactions or corrosion reactions. Hydrogen can also be introduced during
fabrication, for example, during roll forming, machining, and drilling, due to the breakdown of
unsuitable lubricants, as well as during welding or brazing operations.
1. Scope 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This guide covers procedures for reducing the suscep-
ization established in the Decision on Principles for the
tibility in some steels to hydrogen embrittlement or degrada-
Development of International Standards, Guides and Recom-
tion that may arise in the finishing processes.
mendations issued by the World Trade Organization Technical
1.2 The heat treatment procedures established herein may
Barriers to Trade (TBT) Committee.
be effective for reducing susceptibility to hydrogen embrittle-
ment. This heat-treatment procedure shall be used after plating
2. Referenced Documents
operations but prior to any secondary conversion coating
operation. 2.1 ASTM Standards:
A919 Terminology Relating to Heat Treatment of Metals
1.3 ThisguidehasbeencoordinatedwithISO/DIS9588and
(Withdrawn 1999)
is technically equivalent.
B374 Terminology Relating to Electroplating
NOTE1—Theheattreatmentdoesnotguaranteecompletefreedomfrom
B851 Specification for Automated Controlled Shot Peening
the adverse effects of hydrogen degradation.
of Metallic Articles Prior to Nickel, Autocatalytic Nickel,
1.4 The values stated in SI units are to be regarded as
or Chromium Plating, or as Final Finish
standard. No other units of measurement are included in this
2.2 ISO Standards:
standard.
ISO 2080 Electroplating and Related Processes—
1.5 This standard does not purport to address all of the
Vocabulary
safety concerns, if any, associated with its use. It is the
ISO DIS 9588 Post-Coating Treatments of Iron or Steel for
responsibility of the user of this standard to establish appro-
Reducing the Risk of Hydrogen Embrittlement
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This specification is under the jurisdiction of ASTM Committee B08 on Standards volume information, refer to the standard’s Document Summary page on
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee the ASTM website.
B08.02 on Pre Treatment. The last approved version of this historical standard is referenced on
Current edition approved May 1, 2022. Published June 2022. Originally www.astm.org.
approved in 1994. Last previous edition approved in 2015 as B850–98(2015). DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/B0850-98R22. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B850 − 98 (2022)
data. Because of factors such as alloy composition and structure, type of
2.3 Federal Standard:
coating, coating thickness, size, mass, or design parameters, some parts
QQ-C-320 Chromium Plating (Electrodeposited)
may perform satisfactorily with no embrittlement-relief treatment. Class
ER-0 treatment is therefore provided for parts that the purchaser wishes to
3. Terminology
exempt from treatment.
3.1 Definitions—Manyofthetermsusedinthisguidecanbe NOTE 3—The use of inhibitors in acid pickling baths may not minimize
hydrogen embrittlement.
found in Terminology B374, A919, or ISO 2080.
4.4 The electroplater, supplier, or processor is not normally
4. Requirements
in possession of the necessary information, such as design
4.1 Heat treatment may be performed on coated metals to considerations, operating stresses, etc., that must be considered
reduce the risk of hydrogen embrittlement. The duration of when selecting the correct embrittlement relief treatment. It is
heat treatment in all cases shall commence from the time at
in the purchaser’s interest that his or her part designer,
which the whole of each part attains the specified temperature. manufacturing engineer, or other technically qualified indi-
vidual specify the treatment class on the part drawing or
4.2 Parts made from steel with actual tensile strengths
purchase order.
≥1000 MPa (with corresponding hardness values of 300
HV , 303 HB, or 31 HR ) and surface-hardened parts may
10kgf C
5. Embrittlement Relief Treatment Classes
require heat treatment unless Class ER-0 is specified. Prepara-
5.1 With the exception of surface-hardened part
...