ASTM D807-18

Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method)

SIGNIFICANCE AND USE
5.1 Embrittlement is a form of intercrystalline cracking that is associated with the exposure of boiler steel to a combination of physical and chemical factors. For embrittlement of boiler metal to occur, the metal must be under stress, it must be at the site of a leak, and it must be exposed to the concentrated boiler water. In addition, the boiler water must be embrittling in nature. The precise chemical causes of the embrittling nature of some waters are not well understood. Experience has shown that certain waters exhibit an embrittling characteristic while others do not.  
5.2 Because embrittlement is a form of cracking, it is nearly impossible to detect in an operating boiler until a failure has occurred. In general, cracking failures tend to be sudden, and often with serious consequences. This practice offers a way to determine whether a particular water is embrittling or not. It also makes it possible to determine if specific treatment actions have rendered the water nonembrittling.  
5.3 The embrittlement detector was designed to reproduce closely the conditions existing in an actual boiler seam. It is considered probable that the individual conditions of leakage, concentration, and stress in the boiler seam can equal those in the detector. The essential difference between the detector and the boiler is that the former is so constructed and operated that these three major factors act simultaneously, continuously, and under the most favorable circumstances to produce cracking; whereas, in the boiler the three factors are brought together only under unique circumstances. Furthermore, in the detector any cracking is produced in a small test surface that can be inspected thoroughly, while the susceptible areas in a boiler are large and can be inspected only with difficulty. In these respects the embrittlement detector provides an accelerated test of the fourth condition necessary for embrittlement, the embrittling nature of the boiler water.
SCOPE
1.1 This practice,3 known as the embrittlement-detector method, covers the apparatus and procedure for determining the embrittling or nonembrittling characteristics of the water in an operating boiler. The interpretation of the results shall be restricted to the limits set forth in 8.6.  
Note 1: Cracks in a specimen after being subjected to this test indicate that the boiler water can cause embrittlement cracking, but not that the boiler in question necessarily has cracked or will crack.  
1.2 The effectiveness of treatment to prevent cracking, as well as an indication of whether an unsafe condition exists, are shown by this practice. Such treatments are evaluated in terms of method specimen resistance to failure.  
1.3 The practice may be applied to embrittlement resistance testing of steels other than boiler plate, provided that a duplicate, unexposed specimen does not crack when bent 90° on a 2-in. (51-mm) radius.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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: 14-Oct-2018
• ICS: 27.060.30 - Boilers and heat exchangers
• Technical Committee: D19 - Water
• Drafting Committee: D19.03 - Sampling Water and Water-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance of Water

Relations

• Replaces: ASTM D807-14 - Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method)
• Effective Date: 15-Oct-2018
• Refers: ASTM E883-11(2024) - Standard Guide for Reflected–Light Photomicrography
• Effective Date: 01-Apr-2024
• Refers: ASTM A108-24 - Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished
• Effective Date: 01-Mar-2024
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM A108-18 - Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished
• Effective Date: 01-Nov-2018
• Refers: ASTM E883-11(2017) - Standard Guide for Reflected–Light Photomicrography
• Effective Date: 01-Jun-2017
• Refers: ASTM A515/A515M-10(2015) - Standard Specification for Pressure Vessel Plates, Carbon Steel, for Intermediate- and Higher-Temperature Service
• Effective Date: 01-Sep-2015
• Refers: ASTM A108-13 - Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished
• Effective Date: 15-Aug-2013
• Refers: ASTM E883-11 - Standard Guide for Reflected–Light Photomicrography
• Effective Date: 01-May-2011
• Refers: ASTM A515/A515M-10 - Standard Specification for Pressure Vessel Plates, Carbon Steel, for Intermediate- and Higher-Temperature Service
• Effective Date: 01-Oct-2010
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM A515/A515M-03(2007) - Standard Specification for Pressure Vessel Plates, Carbon Steel, for Intermediate- and Higher-Temperature Service
• Effective Date: 01-Nov-2007
• Refers: ASTM A108-07 - Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished
• Effective Date: 01-Sep-2007
• Refers: ASTM E3-01(2007)e1 - Standard Guide for Preparation of Metallographic Specimens
• Effective Date: 01-Jul-2007
• Refers: ASTM E3-01(2007) - Standard Guide for Preparation of Metallographic Specimens
• Effective Date: 01-Jul-2007

Overview

ASTM D807-18: Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method) provides a recognized methodology for evaluating the embrittling or nonembrittling characteristics of water in operating industrial boilers. Embrittlement, often manifesting as intercrystalline cracking in boiler steel, can pose significant safety risks and operational challenges. This standard enables users to systematically test water samples, determine their potential to cause embrittlement, and evaluate the effectiveness of any water treatment programs employed to reduce such risks.

Key Topics

• Embrittlement Phenomenon: Explains the susceptibility of boiler steel to intercrystalline cracking when exposed to specific physical (stress, leakage) and chemical (embrittling water) conditions.

• USBM Embrittlement Detector: Describes the apparatus and procedures designed to simulate actual boiler seam conditions, focusing stress, water concentration, and possible leakage on test specimens for accelerated evaluation.

• Test Methodology:

  • Preparation and installation of test specimens
  • Control of temperature, pressure, and boiler water flow
  • Duration and intervals of testing (typically 30, 60, and 90 operating days)
  • Inspection and assessment for visible signs of cracking

• Assessment of Water Treatments: Provides a practical approach to determining if water chemistry adjustments or treatment protocols have mitigated the tendency for embrittlement.

• Crack Inspection and Evaluation: Details step-by-step guidance for specimen evaluation, including visual and metallographic inspection of cracks, to confirm intercrystalline embrittlement.

Applications

• Industrial Boiler Operations: Essential for facilities using water-tube or fire-tube boilers in sectors such as power generation, chemical processing, and manufacturing.
• Water Treatment Monitoring: Supports plant engineers, maintenance personnel, and water treatment specialists in verifying the effectiveness of water treatment regimens aimed at reducing embrittlement risk.
• Failure Prevention and Safety Compliance: Serves as an early-warning method, helping prevent sudden, catastrophic failures by revealing embrittling tendencies not detectable in routine operation.
• Material Suitability Testing: The standard allows adaptation for evaluating steels other than boiler plate, provided control tests confirm specimen ductility, making it useful for processes involving alternative materials or alloy steels.

Related Standards

• ASTM A108 - Specification for Steel Bar, Carbon and Alloy, Cold-Finished: Specifies materials suitable for embrittlement test specimens.
• ASTM A515/A515M - Specification for Pressure Vessel Plates, Carbon Steel: Used for preparing alternative test specimens.
• ASTM D1129 - Terminology Relating to Water: Ensures clarity in terminology across water testing.
• ASTM D1193 - Specification for Reagent Water: Defines quality requirements for water used in testing.
• ASTM E3, E883, E1351 - Guides for Metallographic Specimen Preparation and Examination: Support inspection of metallographic features in embrittled specimens.

Practical Value

By adopting ASTM D807-18 for industrial boiler water assessment, organizations can:

• Mitigate Operational Risks: Proactively identify embrittling water conditions before they lead to costly or dangerous failures.
• Optimize Maintenance and Inspection: Direct resources toward systems at genuine risk, reducing unnecessary inspections and downtime.
• Comply with International Best Practices: Meet regulatory, insurance, and internal standards for boiler safety and reliability.
• Enhance Water Treatment Strategies: Evaluate and refine water chemistry adjustments using real-world, accelerated feedback from standardized testing.

Keywords: industrial boiler water, embrittlement, USBM embrittlement detector, intercrystalline cracking, water treatment, ASTM D807-18, boiler safety, boiler water testing, metallurgical inspection.

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: D807 − 18
Standard Practice for
Assessing the Tendency of Industrial Boiler Waters to
Cause Embrittlement (USBM Embrittlement Detector
Method)
This standard is issued under the fixed designation D807; 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 priate safety, health, and environmental practices and deter-
3,4 mine the applicability of regulatory limitations prior to use.
1.1 This practice, known as the embrittlement-detector
1.6 This international standard was developed in accor-
method, covers the apparatus and procedure for determining
dance with internationally recognized principles on standard-
the embrittling or nonembrittling characteristics of the water in
ization established in the Decision on Principles for the
an operating boiler. The interpretation of the results shall be
Development of International Standards, Guides and Recom-
restricted to the limits set forth in 8.6.
mendations issued by the World Trade Organization Technical
NOTE1—Cracksinaspecimenafterbeingsubjectedtothistestindicate
Barriers to Trade (TBT) Committee.
that the boiler water can cause embrittlement cracking, but not that the
boiler in question necessarily has cracked or will crack.
2. Referenced Documents
1.2 The effectiveness of treatment to prevent cracking, as
2.1 ASTM Standards:
well as an indication of whether an unsafe condition exists, are
A108 Specification for Steel Bar, Carbon and Alloy, Cold-
shown by this practice. Such treatments are evaluated in terms
Finished
of method specimen resistance to failure.
A515/A515M Specification for Pressure Vessel Plates, Car-
1.3 The practice may be applied to embrittlement resistance bon Steel, for Intermediate- and Higher-Temperature Ser-
vice
testing of steels other than boiler plate, provided that a
D1129 Terminology Relating to Water
duplicate, unexposed specimen does not crack when bent 90°
D1193 Specification for Reagent Water
on a 2-in. (51-mm) radius.
E3 Guide for Preparation of Metallographic Specimens
1.4 The values stated in inch-pound units are to be regarded
E883 Guide for Reflected–Light Photomicrography
as standard. The values given in parentheses are mathematical
E1351 Practice for Production and Evaluation of Field
conversions to SI units that are provided for information only
Metallographic Replicas
and are not considered standard.
1.5 This standard does not purport to address all of the 3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions:
responsibility of the user of this standard to establish appro-
3.1.1 For definitions of terms used in this standard, refer to
Terminology D1129.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 embrittlement cracking, n—a form of metal failure
United States Bureau of Mines.
This test method is under the jurisdiction of ASTM Committee D19 on Water
that occurs in steam boilers at riveted joints and at tube ends,
and is the direct responsibility of Subcommittee D19.03 on Sampling Water and
the cracking being predominantly intercrystalline.
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
3.2.1.1 Discussion—This form of cracking, which has been
On-Line Water Analysis, and Surveillance of Water.
Current edition approved Oct. 15, 2018. Published October 2018. Originally
known as “caustic embrittlement,” is believed to result from
approved in 1944. Last previous edition approved in 2014 as D807 – 14. DOI:
the action of certain constituents of concentrated boiler water
10.1520/D0807-18.
upon steel under stress. For a detailed discussion as to what
This test method was developed during an investigation conducted under a
cracking should be considered significant for the purpose of
cooperative agreement between the Joint Research Committee on Boiler Feedwater
Studies and the United States Bureau of Mines. For information on the development
this practice, see 8.6.
of this test method reference may be made to the following: Schroeder and Berk,
1941 (1); Schroeder, Berk, and Stoddard, 1941 (2); Transactions of the American
Society of Mechanical Engineers, 1942 (3); Whirl and Purcell, 1942 (4); and Berk For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Schroeder, 1943 (5). contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
The boldface numbers in parentheses refer to a list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D807 − 18
4. Summary of Practice site of a leak, and it must be exposed to the concentrated boiler
water. In addition, the boiler water must be embrittling in
4.1 For embrittlement cracking of the boiler metal to be
nature.Theprecisechemicalcausesoftheembrittlingnatureof
possible, the boiler water must concentrate a thousand times or
some waters are not well understood. Experience has shown
more in contact with the metal under high residual or applied
that certain waters exhibit an embrittling characteristic while
tensile stress. In a boiler such concentration may take place in
others do not.
riveted seams or in annular spaces at tube ends, and the steel at
such locations may be highly stressed when the boiler is 5.2 Because embrittlement is a form of cracking, it is nearly
constructedormaybecomehighlystressedwhenitisoperated. impossible to detect in an operating boiler until a failure has
If the chemicals in the boiler water concentrate in the seams to occurred. In general, cracking failures tend to be sudden, and
develop an embrittling solution, cracking may occur. often with serious consequences. This practice offers a way to
determine whether a particular water is embrittling or not. It
4.2 In the embrittlement detector (Fig. 1), the conditions of
alsomakesitpossibletodetermineifspecifictreatmentactions
concentration and stress are provided by the design of the unit.
have rendered the water nonembrittling.
Boiler water is permitted to seep slowly from the small hole
throughtherestrictedspacebetweenthecontactsurfacesofthe 5.3 The embrittlement detector was designed to reproduce
test specimen and the groove in the block. As this extremely closely the conditions existing in an actual boiler seam. It is
slow flow takes place toward atmospheric pressure, the heat in considered probable that the individual conditions of leakage,
the metal and in the liquid causes progressive evaporation to concentration, and stress in the boiler seam can equal those in
produce an increasingly concentrated solution. When the the detector. The essential difference between the detector and
detector is properly adjusted, concentrated boiler water is in the boiler is that the former is so constructed and operated that
contact with the stressed test surface of the specimen, thus these three major factors act simultaneously, continuously, and
providing the necessary factor to determine whether the boiler under the most favorable circumstances to produce cracking;
water can cause embrittlement cracking. whereas, in the boiler the three factors are brought together
only under unique circumstances. Furthermore, in the detector
5. Significance and Use
any cracking is produced in a small test surface that can be
inspectedthoroughly,whilethesusceptibleareasinaboilerare
5.1 Embrittlement is a form of intercrystalline cracking that
largeandcanbeinspectedonlywithdifficulty.Intheserespects
is associated with the exposure of boiler steel to a combination
the embrittlement detector provides an accelerated test of the
of physical and chemical factors. For embrittlement of boiler
fourth condition necessary for embrittlement, the embrittling
metal to occur, the metal must be under stress, it must be at the
nature of the boiler water.
6. Apparatus
6.1 Embrittlement Detector—The embrittlement detector
shall consist of the unit, complete with steel specimen, as
shown assembled in cross section in Fig. 1 and as the installed
unit in Fig. 2.The principal parts consist of a rectangular block
base through which the water circulates and in which a groove
has been machined to receive the test specimen, a test
specimen, and a clamping plate which fits over four stud bolts
in the block. When the nuts on the stud bolts are tightened, the
in. mm in. mm
⁄8 3.17 1 25.4
1 3
⁄2 12.7 1 ⁄8 35
3 3
⁄4 19 2 ⁄4 70
⁄32 21.43
FIG. 1 Cross-Section of Embrittlement Detector FIG. 2 Embrittlement Detector Installed
D807 − 18
in. mm in. mm in. mm in. mm
1 11 3 1
⁄64 0.39 ⁄16 17.46 1 ⁄16 30 2 ⁄4 57
1 23 1 3
⁄8 3.17 ⁄32 18.25 1 ⁄4 31.7 2 ⁄8 60
3 3 11 1
⁄16 4.76 ⁄4 19 1 ⁄16 42.8 2 ⁄2 63.5
5 13 3 9
⁄16 7.93 ⁄16 20.63 1 ⁄4 44.4 2 ⁄16 65
3 7 13 1
⁄8 9.52 ⁄8 22.22 1 ⁄16 46 3 ⁄8 79
27 7 1
⁄64 10.71 1 25.4 1 ⁄8 47.6 3 ⁄2 89
1 1
⁄2 12.7 1 ⁄8 28.6 2 50.8 5 127
⁄8 15.87
FIG. 3 Dimensional Details of Base Block of Embrittlement Detector
pressure of the clamping plate molds the test specimen to the
contour of the groove, thus stressing in tension the surface of
thespecimen.Workingdrawingsshowingthedimensionsofall
the machined parts are shown in Figs. 3-5.Accurate machining
of the groove with respect to the small hole through which the
boiler water is brought to the test surface of the specimen is
especially important.
6.2 Wrenches—An extra-heavy box-type wrench of 1 ⁄16-in.
(27-mm) opening is recommended for assembling and adjust-
ing the unit. A lighter box-type wrench of ⁄4-in. (19-mm)
opening is recommended for the hexagonal head of the
adjusting screw in the end of the specimen. in. mm in. mm
6.3 Jig for Bending Specimen—Ajig as shown in Fig. 6,or 1 3
⁄8 3.17 ⁄8 22.22
⁄16 7.93 1 25.4
its equivalent, is recommended for bending the specimen with
5 3
⁄8 15.87 1 ⁄8 35
ahydraulicpressattheendofthetesttorevealcracksthatmay
3 7
⁄4 19 1 ⁄8 47.6
13 1
have been formed but are too fine to be visible without
⁄16 20.63 3 ⁄2 89
additional stressing of the steel surface. Other devices may be
FIG. 4 Dimensional Details of Clamping Plate of Embrittlement
substituted to affect the same purpose of bending the specimen
Detector
uniformly in the proper place without injuring the surface to be
studied (Note 2). A vise and sledge hammer shall not be used.
D807 − 18
NOTE 3—Where specimens of cold-rolled steel have been cracked,
similar specimens machined from boiler plate conforming to Specification
A515/A515M, or hot-rolled steel of comparable composition may be
tested to determine the severity of the embrittling condition. Hot-rolled
steel has proved less susceptible to cracking than cold-rolled steel.
NOTE 4—Alloy steels are often more susceptible for cracking than the
standard cold-rolled steel specified for test specimens. Where the water
tested is used in alloy-steel boilers, it is desirable that the test specimen be
prepared from the same material or from bars of similar composition and
physical properties.
8.1.2 Finish the test surface of the specimen by either
grinding with a surface grinder to a finish comparable to that
produced by No. 2 metallographic polishing paper, or milling
to remove surface imperfections and smoothing with No. 2
metallographic paper to remove the cutter marks. Grind and
polish along the length of the specimen. If the specimen
in. mm in. mm
surfacestillshowsvisibleflaws,suchasholes,oxide,orrolling
marks, after 0.01 in. (0.2 mm) has been removed, discard the
0.010 0.25 ⁄4 19
⁄64 1.19 5 127
specimen and prepare another one.
⁄2 12.7
8.1.3 Beveltheedgesofthetestsurface5°,asshowninFig.
5.
FIG. 5 Dimensional Details of Test Specimen
8.1.4 Center the threaded hole in the specimen for the
adjusting screw and tap as specified in Fig. 5 so that the cap
screwisperpendiculartothesurface.Theadjustingscrewshall
be sufficiently free so that it can be turned easily with the
fingers.
NOTE 5—Specimens that have been prepared in accordance with the
directions given in Section 8 may be obtained from the major water-
treating companies.
8.2 Assembly of Specimen and Detector:
8.2.1 When a new specimen is to be installed in the detector
(Note 6), clean the block, especially the surface of the groove,
with hot water to dissolve soluble solids, and scrape lightly to
NOTE 1—Rectangular Bars of 1-in. (25-mm) Cold-Rolled Plate Held
remove less soluble incrustations. Polish the groove with fine
Together by 1-in. (25-mm) Bolts. Distance between Bars 3 ⁄4 in. (82 mm).
emery cloth. Finally open the inlet valve for an instant to make
Pressure Transmitted by a 1 ⁄2 in. (38 mm) Round Bar.
sure that the small leakage hole is cleaned out, then wipe the
FIG. 6 Jig for Bending Specimen after Test
groove clean.Treat the stud threads with graphite suspended in
1 oil (Note 7).
NOTE 2—The surface to be studied is the stressed area, which starts ⁄4
in. (6 mm) above the spot corresponding to the opening in the test block
NOTE 6—When received from the manufacturer the detector is already
and extends about 1 in. (25 mm) toward the adjusting screw.
assembled with the specimen in position and should be steam tight. It is
6.4 Grinding/polishing equipment. recommended that the specimen not be removed from the detector until
after the first test is completed.
6.5 Magnifying glass, for inspecting for crack
NOTE 7—Alittle graphite suspended in oil applied to the threads of the
studs and the adjusting screw will minimize seizing. Use kerosene instead
7. Reagents and Materials
of oil if the pressure is greater than 500 psi (3.5 MPa).
7.1 Purity of Reagents—Unless otherwise indic
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D807 − 14 D807 − 18
Standard Practice for
Assessing the Tendency of Industrial Boiler Waters to
Cause Embrittlement (USBM Embrittlement Detector
1,2
Method)
This standard is issued under the fixed designation D807; 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
1.1 This practice, known as the embrittlement-detector method, covers the apparatus and procedure for determining the
embrittling or nonembrittling characteristics of the water in an operating boiler. The interpretation of the results shall be restricted
to the limits set forth in 8.6.
NOTE 1—The embrittlement detector was designed to reproduce closely the conditions existing in an actual boiler seam. It is considered probable that
the individual conditions of leakage, concentration, and stress in the boiler seam can equal those in the detector. The essential difference between the
detector and the boiler is that the former is so constructed and operated that these three major factors act simultaneously, continuously, and under the most
favorable circumstances to produce cracking; whereas, in the boiler the three factors are brought together only under unique circumstances. Furthermore,
in the detector any cracking is produced in a small test surface that can be inspected thoroughly, while the susceptible areas in a boiler are large and can
be inspected only with difficulty. In these respects the embrittlement detector provides an accelerated test of the fourth condition necessary for
embrittlement, the embrittling nature of the boiler water.
NOTE 1—Cracks in a specimen after being subjected to this test indicate that the boiler water can cause embrittlement cracking, but not that the boiler
in question necessarily has cracked or will crack.
1.2 The effectiveness of treatment to prevent cracking, as well as an indication of whether an unsafe condition exists, are shown
by this practice. Such treatments are evaluated in terms of method specimen resistance to failure.
1.3 The practice may be applied to embrittlement resistance testing of steels other than boiler plate, provided that a duplicate,
unexposed specimen does not crack when bent 90° on a 2-in. (51-mm) radius.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered 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.
2. Referenced Documents
2.1 ASTM Standards:
A108 Specification for Steel Bar, Carbon and Alloy, Cold-Finished
A515/A515M Specification for Pressure Vessel Plates, Carbon Steel, for Intermediate- and Higher-Temperature Service
D1129 Terminology Relating to Water
This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.03 on Sampling Water and
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance of Water.
Current edition approved Jan. 1, 2014Oct. 15, 2018. Published January 2014October 2018. Originally approved in 1944. Last previous edition approved in 20092014 as
D807 – 05 (2009).D807 – 14. DOI: 10.1520/D0807-14.10.1520/D0807-18.
United States Bureau of Mines.
This test method was developed during an investigation conducted under a cooperative agreement between the Joint Research Committee on Boiler Feedwater Studies
and the United States Bureau of Mines. For information on the development of this test method reference may be made to the following: Schroeder and Berk, 1941 (1);
Schroeder, Berk, and Stoddard, 1941 (2); Transactions of the American Society of Mechanical Engineers, 1942 (3); Whirl and Purcell, 1942 (4); and Berk and Schroeder,
1943 (5).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D807 − 18
D1193 Specification for Reagent Water
E3 Guide for Preparation of Metallographic Specimens
E883 Guide for Reflected–Light Photomicrography
E1351 Practice for Production and Evaluation of Field Metallographic Replicas
3. Terminology
3.1 DefinitionsDefinitions:—For
3.1.1 For definitions of terms used in this standard, refer to Terminology D1129. definitions of other terms used in this practice,
refer to Terminology D1129.
D807 − 18
3.2 Definitions of Terms Specific to This Standard:
3.2.1 embrittlement cracking, n—a form of metal failure that occurs in steam boilers at riveted joints and at tube ends, the
cracking being predominantly intercrystalline.
3.2.1.1 Discussion—
This form of cracking, which has been known as “caustic embrittlement,” is believed to result from the action of certain
constituents of concentrated boiler water upon steel under stress. For a detailed discussion as to what cracking should be considered
significant for the purpose of this practice, see 8.6.
4. Summary of Practice
4.1 For embrittlement cracking of the boiler metal to be possible, the boiler water must concentrate a thousand times or more
in contact with the metal under high residual or applied tensile stress. In a boiler such concentration may take place in riveted seams
or in annular spaces at tube ends, and the steel at such locations may be highly stressed when the boiler is constructed or may
become highly stressed when it is operated. If the chemicals in the boiler water concentrate in the seams to develop an embrittling
solution, cracking may occur.
4.2 In the embrittlement detector (Fig. 1), the conditions of concentration and stress are provided by the design of the unit.
Boiler water is permitted to seep slowly from the small hole through the restricted space between the contact surfaces of the test
specimen and the groove in the block. As this extremely slow flow takes place toward atmospheric pressure, the heat in the metal
and in the liquid causes progressive evaporation to produce an increasingly concentrated solution. When the detector is properly
adjusted, concentrated boiler water is in contact with the stressed test surface of the specimen, thus providing the necessary factor
to determine whether the boiler water can cause embrittlement cracking.
5. Significance and Use
5.1 Embrittlement is a form of intercrystalline cracking that is associated with the exposure of boiler steel to a combination of
physical and chemical factors. For embrittlement of boiler metal to occur, the metal must be under stress, it must be at the site of
a leak, and it must be exposed to the concentrated boiler water. In addition, the boiler water must be embrittling in nature. The
in. mm in. mm
⁄8 3.17 1 25.4
1 3
⁄2 12.7 1 ⁄8 35
3 3
⁄4 19 2 ⁄4 70
⁄32 21.43
FIG. 1 Cross-Section of Embrittlement Detector
D807 − 18
precise chemical causes of the embrittling nature of some waters are not well understood. Experience has shown that certain waters
exhibit an embrittling characteristic while others do not.
5.2 Because embrittlement is a form of cracking, it is nearly impossible to detect in an operating boiler until a failure has
occurred. In general, cracking failures tend to be sudden, and often with serious consequences. This practice offers a way to
determine whether a particular water is embrittling or not. It also makes it possible to determine if specific treatment actions have
rendered the water nonembrittling.
5.3 The embrittlement detector was designed to reproduce closely the conditions existing in an actual boiler seam. It is
considered probable that the individual conditions of leakage, concentration, and stress in the boiler seam can equal those in the
detector. The essential difference between the detector and the boiler is that the former is so constructed and operated that these
three major factors act simultaneously, continuously, and under the most favorable circumstances to produce cracking; whereas,
in the boiler the three factors are brought together only under unique circumstances. Furthermore, in the detector any cracking is
produced in a small test surface that can be inspected thoroughly, while the susceptible areas in a boiler are large and can be
inspected only with difficulty. In these respects the embrittlement detector provides an accelerated test of the fourth condition
necessary for embrittlement, the embrittling nature of the boiler water.
6. Apparatus
6.1 Embrittlement Detector—The embrittlement detector shall consist of the unit, complete with steel specimen, as shown
assembled in cross section in Fig. 1 and as the installed unit in Fig. 2. The principal parts consist of a rectangular block base
through which the water circulates and in which a groove has been machined to receive the test specimen, a test specimen, and
a clamping plate which fits over four stud bolts in the block. When the nuts on the stud bolts are tightened, the pressure of the
clamping plate molds the test specimen to the contour of the groove, thus stressing in tension the surface of the specimen. Working
drawings showing the dimensions of all the machined parts are shown in Figs. 3-5. Accurate machining of the groove with respect
to the small hole through which the boiler water is brought to the test surface of the specimen is especially important.
6.2 Wrenches—An extra-heavy box-type wrench of 1 ⁄16-in. (27-mm) opening is recommended for assembling and adjusting the
unit. A lighter box-type wrench of ⁄4-in. (19-mm) opening is recommended for the hexagonal head of the adjusting screw in the
end of the specimen.
6.3 Jig for Bending Specimen—A jig as shown in Fig. 6, or its equivalent, is recommended for bending the specimen with a
hydraulic press at the end of the test to reveal cracks that may have been formed but are too fine to be visible without additional
stressing of the steel surface. Other devices may be substituted to affect the same purpose of bending the specimen uniformly in
the proper place without injuring the surface to be studied (Note 32). A vise and sledge hammer shall not be used.
FIG. 2 Embrittlement Detector Installed
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in. mm in. mm in. mm in. mm
1 11 3 1
⁄64 0.39 ⁄16 17.46 1 ⁄16 30 2 ⁄4 57
1 23 1 3
⁄8 3.17 ⁄32 18.25 1 ⁄4 31.7 2 ⁄8 60
3 3 11 1
⁄16 4.76 ⁄4 19 1 ⁄16 42.8 2 ⁄2 63.5
5 13 3 9
⁄16 7.93 ⁄16 20.63 1 ⁄4 44.4 2 ⁄16 65
3 7 13 1
⁄8 9.52 ⁄8 22.22 1 ⁄16 46 3 ⁄8 79
27 7 1
⁄64 10.71 1 25.4 1 ⁄8 47.6 3 ⁄2 89
1 1
⁄2 12.7 1 ⁄8 28.6 2 50.8 5 127
⁄8 15.87
FIG. 3 Dimensional Details of Base Block of Embrittlement Detector
in. mm in. mm
1 3 in. mm in. mm
⁄8 3.17 ⁄8 22.22
in. mm in. mm
⁄16 7.93 1 25.4
5 3
⁄8 15.87 1 ⁄8 35
3 7 0.010 0.25 ⁄4 19
⁄4 19 1 ⁄8 47.6
0.010 0.25 ⁄4 19
13 1
⁄16 20.63 3 ⁄2 89
⁄64 1.19 5 127
⁄2 12.7
FIG. 4 Dimensional Details of Clamping Plate of Embrittlement
⁄64 1.19 5 127
Detector
⁄2 12.7
FIG. 5 Dimensional Details of Test Specimen
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NOTE 1—Rectangular Bars of 1-in. (25-mm) Cold-Rolled Plate Held Together by 1-in. (25-mm) Bolts. Distance between Bars 3 ⁄4 in. (82 mm). Pressure
Transmitted by a 1 ⁄2 in. (38 mm) Round Bar.
FIG. 6 Jig for Bending Specimen after Test
NOTE 2—The surface to be studied is the stressed area, which starts ⁄4 in. (6 mm) above the spot corresponding to the opening in the test block and
extends about 1 in. (25 mm) toward the adjusting screw.
6.4 Grinding/polishing equipment.
6.5 Magnifying glass, for inspecting for crack
7. Reagents and Materials
7.1 Purity of Reagents—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming
to Type IV of Specification D1193.
7.2 Kerosine, commercial grade.
7.3 Lubricating oil, commercial grade for thread lubrication.
7.4 Graphite, commercial grade for thread lubrication.
8. Procedure
8.1 Test Specimens:
1 3 1 3
8.1.1 Cut test specimens ⁄2 by ⁄4 by 5 in. (13 by 19 by 127 mm) from ⁄2 by ⁄4-in. (13 by 19-mm) cold-finished bar stock (Note
43 and Note 54) conforming to Grade 1020 of Specification A108.
NOTE 3—Where specimens of cold-rolled steel have been cracked, similar specimens machined from boiler plate conforming to Specification
A515/A515M, or hot-rolled steel of comparable composition may be tested to determine the severity of the embrittling condition. Hot-rolled steel has
proved less susceptible to cracking than cold-rolled steel.
NOTE 4—Alloy steels are often more susceptible for cracking than the standard cold-rolled steel specified for test specimens. Where the water tested
is used in alloy-steel boilers, it is desirable that the test specimen be prepared from the same material or from bars of similar composition and physical
properties.
8.1.2 Finish the test surface of the specimen by either grinding with a surface grinder to a finish comparable to that produced
by No. 2 metallographic polishing paper, or milling to remove surface imperfections and smoothing with No. 2 metallographic
paper to remove the cutter marks. Grind and polish along the length of the specimen. If the specimen surface still shows visible
flaws, such as holes, oxide, or rolling marks, after 0.01 in. (0.2 mm) has been removed, discard the specimen and prepare another
one.
8.1.3 Bevel the edges of the test surface 5°, as shown in Fig. 5.
8.1.4 Center the threaded hole in the specimen for the adjusting screw and tap as specified in Fig. 5 so that the cap screw is
perpendicular to the surface. The adjusting screw shall be sufficiently free so that it can be turned easily with
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