ASTM D807-05(2009)
(Practice)Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method)
Standard Practice for Assessing the Tendency of Industrial Boiler Waters to Cause Embrittlement (USBM Embrittlement Detector Method)
SIGNIFICANCE AND USE
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 is not well understood. Experience has shown that certain waters exhibit an embrittling characteristic while others do not.
Because embrittlement is a form of cracking, it is nearly impossible to detect in an operating boiler until a failure has occured. 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.
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 Section 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 2—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 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 and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D807 − 05(Reapproved 2009)
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 1.2 The effectiveness of treatment to prevent cracking, as
3 well as an indication of whether an unsafe condition exists, are
1.1 This practice, known as the embrittlement-detector
shown by this practice. Such treatments are evaluated in terms
method, covers the apparatus and procedure for determining
of method specimen resistance to failure.
the embrittling or nonembrittling characteristics of the water in
an operating boiler. The interpretation of the results shall be 1.3 The practice may be applied to embrittlement resistance
restricted to the limits set forth in Section 8.6. testing of steels other than boiler plate, provided that a
duplicate, unexposed specimen does not crack when bent 90°
NOTE1—Theembrittlementdetectorwasdesignedtoreproduceclosely
on a 2-in. (51-mm) radius.
the conditions existing in an actual boiler seam. It is considered probable
that the individual conditions of leakage, concentration, and stress in the
1.4 This standard does not purport to address all of the
boiler seam can equal those in the detector. The essential difference
safety concerns, if any, associated with its use. It is the
between the detector and the boiler is that the former is so constructed and
responsibility of the user of this standard to establish appro-
operated that these three major factors act simultaneously, continuously,
priate safety and health practices and determine the applica-
andunderthemostfavorablecircumstancestoproducecracking;whereas,
in the boiler the three factors are brought together only under unique
bility of regulatory limitations prior to use.
circumstances. Furthermore, in the detector any cracking is produced in a
small test surface that can be inspected thoroughly, while the susceptible
2. Referenced Documents
areas in a boiler are large and can be inspected only with difficulty. In
these respects the embrittlement detector provides an accelerated test of 2.1 ASTM Standards:
the fourth condition necessary for embrittlement, the embrittling nature of
A108 Specification for Steel Bar, Carbon and Alloy, Cold-
the boiler water.
Finished
NOTE2—Cracksinaspecimenafterbeingsubjectedtothistestindicate
A515/A515M Specification for Pressure Vessel Plates, Car-
that the boiler water can cause embrittlement cracking, but not that the
bon Steel, for Intermediate- and Higher-Temperature Ser-
boiler in question necessarily has cracked or will crack.
vice
D1129 Terminology Relating to Water
United States Bureau of Mines.
D1193 Specification for Reagent Water
This test method is under the jurisdiction of ASTM Committee D19 on Water
E3 Guide for Preparation of Metallographic Specimens
and is the direct responsibility of Subcommittee D19.03 on Sampling Water and
E883 Guide for Reflected–Light Photomicrography
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
On-Line Water Analysis, and Surveillance of Water.
E1351 Practice for Production and Evaluation of Field
Current edition approved Oct. 1, 2009. Published November 2009. Originally
Metallographic Replicas
approved in 1944. Last previous edition approved in 2005 as D807 – 05. DOI:
10.1520/D0807-05R09.
This test method was developed during an investigation conducted under a 3. Terminology
cooperative agreement between the Joint Research Committee on Boiler Feedwater
3.1 Definitions:
Studies and the United States Bureau of Mines.
For information on the development of this test method reference may be made 3.1.1 The term embrittlement cracking in this test method is
to the following:
defined in accordance with Terminology D1129 as follows:
Schroeder, W. C. and Berk, A. A. “Intercrystalline Cracking of Boiler Steel and
3.1.1.1 embrittlement cracking—aformofmetalfailurethat
Its Prevention,” Bulletin 443, U.S. Bureau of Mines, 1941.
occurs in steam boilers at riveted joints and at tube ends, the
Schroeder, W. C., Berk, A. A. and Stoddard, C. K. “Embrittlement Detector
Testing on Boilers,” Power Plant Engineering, Vol 45, August, 1941, pp. 69–76.
cracking being predominantly intercrystalline.
“Embrittlement Symposium,” Transactions of the Am. Soc. Mech. Engrs., Vol
64, 1942, pp. 393–444.
Whirl, S. F. and Purcell, T. E. “Protection Against Caustic Embrittlement by
Coordinated Phosphate-pH Control,” Proceedings,ThirdAnnualWater Conference, For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Engrs. Soc. of Western Penna., 1942, pp. 45–60. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Berk, A. A. and Schroeder, W. C. “A Practical Way to Prevent Embrittlement Standards volume information, refer to the standard’s Document Summary page on
Cracking,” Transactions, Am. Soc. Mech. Engr., Vol 65, 1943, pp. 701–711. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D807 − 05 (2009)
NOTE 3—This form of cracking, which has been known as “caustic
embrittlement,”isbelievedtoresultfromtheactionofcertainconstituents
of concentrated boiler water upon steel under stress.
NOTE 4—For a detailed discussion as to what cracking should be
considered significant for the purpose of this practice, see Section 8.6.
3.1.2 For definitions of other terms used in this practice,
refer to Terminology D1129.
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
constructedormaybecomehighlystressedwhenitisoperated.
If the chemicals in the boiler water concentrate in the seams to
FIG. 2 Embrittlement Detector Installed
develop an embrittling solution, cracking may occur.
4.2 In the embrittlement detector (Fig. 1), the conditions of
water. In addition, the boiler water must be embrittling in
concentration and stress are provided by the design of the unit.
nature.Theprecisechemicalcausesoftheembrittlingnatureof
Boiler water is permitted to seep slowly from the small hole
some waters is not well understood. Experience has shown that
through the restricted space between the contact surfaces of the
certain waters exhibit an embrittling characteristic while others
test specimen and the groove in the block. As this extremely
do not.
slow flow takes place toward atmospheric pressure, the heat in
the metal and in the liquid causes progressive evaporation to
5.2 Because embrittlement is a form of cracking, it is nearly
produce an increasingly concentrated solution. When the
impossible to detect in an operating boiler until a failure has
detector is properly adjusted, concentrated boiler water is in
occured. In general, cracking failures tend to be sudden, and
contact with the stressed test surface of the specimen, thus
often with serious consequences. This practice offers a way to
providing the necessary factor to determine whether the boiler
determine whether a particular water is embrittling or not. It
water can cause embrittlement cracking.
also makes it possible to determine if specific treatment actions
have rendered the water nonembrittling.
5. Significance and Use
6. Apparatus
5.1 Embrittlement is a form of intercrystalline cracking that
is associated with the exposure of boiler steel to a combination
6.1 Embrittlement Detector—The embrittlement detector
of physical and chemical factors. For embrittlement of boiler
shall consist of the unit, complete with steel specimen, as
metal to occur, the metal must be under stress, it must be at the
shown assembled in cross section in Fig. 1 and as the installed
site of a leak, and it must be exposed to the concentrated boiler
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 (Note 4) showing the dimen-
sionsofallthemachinedpartsareshowninFigs.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 27-mm
(1 ⁄16-in.) opening is recommended for assembling and adjust-
ing the unit. A lighter box-type wrench of 19-mm ( ⁄4-in.)
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
ahydraulicpressattheendofthetesttorevealcracksthatmay
have been formed but are too fine to be visible without
FIG. 1 Cross-Section of Embrittlement Detector additional stressing of the steel surface. Other devices may be
D807 − 05 (2009)
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
⁄8 3.17 ⁄8 22.22
⁄16 7.93 1 25.4
in. mm in. mm
5 3
⁄8 15.87 1 ⁄8 35
0.010 0.25 ⁄4 19
3 7
⁄4 19 1 ⁄8 47.6
⁄64
1.19 5 127
13 1
⁄16 20.63 3 ⁄2 89
⁄2 12.7
FIG. 4 Dimensional Details of Clamping Plate of Embrittlement
FIG. 5 Dimensional Details of Test Specimen
Detector
NOTE 5—The surface to be studied is the stressed area, which starts 6
mm ( ⁄4 in.) above the spot corresponding to the opening in the test block
substituted to effect the same purpose of bending the specimen
and extends about 25 mm (1 in.) toward the adjusting screw.
uniformly in the proper place without injuring the surface to be
studied (Note 5). A vise and sledge hammer shall not be used. 7. Reagents
D807 − 05 (2009)
remove less soluble incrustations. Polish the groove with fine
emery cloth. Finally open the inlet valve for an instant to make
sure that the small leakage hole is cleaned out, then wipe the
groove clean.Treat the stud threads with graphite suspended in
oil (Note 10).
NOTE 9—When received from the manufacturer the detector is already
assembled with the specimen in position and should be steam tight. It is
recommended that the specimen not be removed from the detector until
after the first test is completed.
NOTE10—Alittlegraphitesuspendedinoilappliedtothethreadsofthe
studs and the adjusting screw will minimize seizing. Use kerosine instead
of oil if the pressure is greater than 3.5 MPa (500 psi).
NOTE 1—Rectangular Bars of 1-in. (25 mm) Cold-Rolled Plate Held
1 8.2.2 To assemble the specimen and the detector, center the
Togetherby1-in.Bolts.DistanceBetweenBars3 ⁄4 in.(82mm).Pressure
Transmitted by a 1 ⁄2 in. (38 mm) Round Bar. specimen with the smoothed surface facing the groove of the
FIG. 6 Jig for Bending Specimen After Test
blocksothattheendwiththeadjustingscrewholeisflushwith
theendoftheblocknotgrooved.Placetheclampingplateover
the studs, with the beveled edge inward and toward the end of
7.1 Purity of Reagents—Unless otherwise indicated, refer-
the specimen containing the adjusting screw. Place the washers
ences to water shall be understood to mean reagent water
and nuts on the studs. Tighten alternately and evenly first the
conforming to Type IV of Specification D1193.
nuts on the top pairs of studs (Note 10) in the center of the
8. Procedure detector block, thus forcing the surface of the test specimen to
conform to the curvature of the groove. Then tighten the nuts
8.1 Test Specimens
on the bottom pair of studs. Finally tighten the nuts on the top
1 3
8.1.1 Cut test specimens 13 by 19 by 127 mm ( ⁄2 by ⁄4 by
pair of studs to bring the surfaces close enough together so that
1 3
5 in.) from 13 by 19-mm ( ⁄2 by ⁄4-in.) cold-finished bar stock
the small hole in the detector block groove is sealed.
(Note6andNote7)conformingtoGrade1020ofSpecification
A108.
NOTE 11—There shall be no leakage from the detector when the valves
are opened and water at full boiler pressure flows through the block.
NOTE 6—Where specimens of cold-rolled steel have been cracked,
similar specimens machined from boiler plate conforming to Specification
8.2.3 Insert the adjusting screw in the specimen and turn it
A515/A515M, or hot-rolled steel of comparable composition may be
down with the fingers until it just touches the block.
tested to determine the severity of the embrittling condition. Hot-rolled
steel has proved less susceptible to cracking than cold-rolled steel.
8.3 Installation of Detector
NOTE 7—Alloy steels are often more susceptible for cracking than the
8.3.1 Connect the assembled detector to the operating boiler
standard cold-rolled steel specified for test specimens. Where the water
so that boiler water will circulate through the block (Note 12).
tested is used in alloy-steel boilers, it is desirable that the test specimen be
Flush clean the inlet line to the detector before the detector is
prepared from the same material or from bars of similar composition and
physical properties.
attached.
8.1.2 Finish the test surface of the specimen by either
NOTE 12—The detector may be installed in a bypass to a continuous
grinding with a surface grinder to a finish comparable to that
blow-down line or in a recirculating line if one is available. The effluent
produced by No. 2 metallographic polishing paper, or milling
from the detector may be returned to the boiler or discharged to waste.
to remove surface imperfections and smoothing with No. 2
8.3.2 Maintain the temperature and pressure of the water
metallographic paper to remove the cutter marks. Grind and
circulating through the detector
...
This document is not anASTM standard and is intended only to provide the user of anASTM 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.
An American National Standard Designation: D807 – 05 (Reapproved 2009)
Designation:D 807–00
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
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 Section 128.6.
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 2—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 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
A108 Specification for Steel Bars, Carbon, Cold-Finished, Standard Quality 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 Terminology Relating to Water
United States Bureau of Mines.
This test method is under the jurisdiction of ASTM Committee D–19 on Water and is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
Water-Formed Deposits, Surveillamce of Water and Flow Measurement of Water.
Current edition approved June 10, 2000. Published September 2000. Originally published as D807–44T. Last previous edition D807–96.
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 Oct. 1, 2009. Published November 2009. Originally approved in 1944. Last previous edition approved in 2005 as D807 – 05. DOI:
10.1520/D0807-05R09.
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, W. C. and Berk, A. A. “Intercrystalline Cracking of Boiler Steel and Its Prevention,” Bulletin 443, U.S. Bureau of Mines, 1941.
Schroeder, W. C., Berk, A. A. and Stoddard, C. K. “Embrittlement Detector Testing on Boilers,” Power Plant Engineering , Vol 45, August, 1941, pp. 69–76.
“Embrittlement Symposium,” Transactions of the Am. Soc. Mech. Engrs., Vol 64, 1942, pp. 393–444.
Whirl, S. F. and Purcell, T. E. “Protection Against Caustic Embrittlement by Coordinated Phosphate-pH Control,” Proceedings , Third Annual Water Conference, Engrs.
Soc. of Western Penna., 1942, pp. 45–60.
Berk, A. A. and Schroeder, W. C. “A Practical Way to Prevent Embrittlement Cracking,” Transactions, Am. Soc. Mech. Engr., Vol 65, 1943, pp. 701–711.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 01.05.volume information, refer to the standard’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.
D807–05 (2009)
D1193 Specification for Reagent Water
E3 Methods of Preparation of Metallographic Specimens Guide for Preparation of Metallographic Specimens
E883 Guide for Reflected-Light Photomicrography Guide for ReflectedLight Photomicrography
E1351 Practice for Production and Evaluation of Field Metallographic Replicas
3. Terminology
3.1 Definitions:
3.1.1 The term embrittlement cracking in this test method is defined in accordance with Terminology D 1129D1129 as follows:
3.1.1.1 embrittlement cracking—a form of metal failure that occurs in steam boilers at riveted joints and at tube ends, the
cracking being predominantly intercrystalline.
NOTE 3—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.
NOTE 4—For a detailed discussion as to what cracking should be considered significant for the purpose of this practice, see Section 128.6.
3.1.2 For definitions of other terms used in this practice, refer to Terminology D 1129D1129.
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
incontactwiththemetalunderhighresidualorappliedtensilestress.Inaboilersuchconcentrationmaytakeplaceinrivetedseams
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
precise chemical causes of the embrittling nature of some waters is 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
occured. 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.
FIG. 1 Cross-Section of Embrittlement Detector
D807–05 (2009)
FIG. 2 Embrittlement Detector Installed
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
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 (Note 4) showing the dimensions of all the machined parts are shown in Figs. 3-5. Accurate machining of the groove
D807–05 (2009)
in. mm in. mm
1 3
⁄8 3.17 ⁄8 22.22
⁄16 7.93 1 25.4
5 3
⁄8 15.87 1 ⁄8 35
3 7
⁄4 19 1 ⁄8 47.6
13 1
⁄16 20.63 3 ⁄2 89
FIG. 4 Dimensional Details of Clamping Plate of Embrittlement
Detector
in. mm in. mm
0.010 0.25 ⁄4 19
⁄64 1.19 5 127
⁄2 12.7
FIG. 5 Dimensional Details of Test Specimen
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—Anextra-heavybox-typewrenchof27-mm(1 ⁄16-in.)openingisrecommendedforassemblingandadjustingthe
unit. A lighter box-type wrench of 19-mm ( ⁄4-in.) 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 effect the same purpose of bending the specimen uniformly in
the proper place without injuring the surface to be studied (Note 5). A vise and sledge hammer shall not be used.
NOTE 5—The surface to be studied is the stressed area, which starts 6 mm ( ⁄4 in.) above the spot corresponding to the opening in the test block and
extends about 25 mm (1 in.) toward the adjusting screw.
7. Test Specimens
7.1Cut test specimens 13 by 19 by 127 mm ( ⁄2 Reagents
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.
8. Procedure
8.1 Test Specimens
1 3 1 3
8.1.1 Cut test specimens 13 by 19 by 127 mm ( ⁄2 by ⁄4 by 5 in.) from 13 by 19-mm ( ⁄2 by ⁄4-in.) cold-finished bar stock (Note
D807–05 (2009)
NOTE—Rectangular Bars of 1-in. (25 mm) Cold-Rolled Plate Held
Togetherby1-in.Bolts.DistanceBetweenBars3 ⁄4 in.(82mm).Pressure
Transmitted by a 1 ⁄2 in. (38 mm) Round Bar.
FIG. 6 Jig for Bending Specimen After Test
6 and Note 7) conforming to Grade 1020 of Specification A 108A108.
NOTE 6—Where specimens of cold-rolled steel have been cracked, similar specimens machined from boiler plate conforming to Specification A
515A515/A515M/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 7—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.
78.1.2 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 0.2 mm (0.01 in.) has been removed, discard the specimen and prepare another
one.
7.3Bevel8.1.3 Bevel the edges of the test surface 5°, as shown in Fig. 5.
78.1.4 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 the fingers.
NOTE 8—Specimens that have been prepared in accordance with the directions given in Section 7 8 may be obtained from the major water-treating
companies. 8.
8.2 Assembly of Specimen and Detector
8.2.1 When a new specimen is to be installed in the detector (Note 9), clean the block, especially the surface of the groove, with
hotwatertodissolvesolublesolids,andscrapelightlytoremovelesssolubleincrustations.Polishthegroovewithfineemerycloth.
Finally open the inlet valve for an instant to make sure that the small leakage hole is cleaned out, then wipe the groove clean.Treat
the stud threads with graphite suspended in oil (Note
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