ASTM E1928-99

Standard Practice for Estimating the Approximate Residual Circumferential Stress in Straight Thin-walled Tubing

SCOPE
1.1 A qualitative estimate of the residual circumferential stress in thin-walled tubing may be calculated from the change in outside diameter that occurs upon splitting a length of the tubing. The Hatfield and Thirkell formula, as later modified by Sachs and Espey, provides a simple method for calculating the approximate circumferential stress from the change in diameter of straight, thin-walled, metal tubing.  
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.

General Information

• Status: Historical
• Publication Date: 09-Oct-1999
• ICS: 23.040.10 - Iron and steel pipes
• ICS: 23.040.15 - Non-ferrous metal pipes
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.13 - Residual Stress Measurement

Relations

• Replaced By: ASTM E1928-07 - Standard Practice for Estimating the Approximate Residual Circumferential Stress in Straight Thin-walled Tubing
• Effective Date: 01-Mar-2007

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E1928–99
Standard Practice for
Estimating the Approximate Residual Circumferential Stress
in Straight Thin-walled Tubing
This standard is issued under the fixed designation E 1928; 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 (e) indicates an editorial change since the last revision or reapproval.
TABLE 1 Residual Stresses in Successive Heats of Tubing
1. Scope
Ferritic Cr-Mo-Ni Stainless Steel Titanium
1.1 A qualitative estimate of the residual circumferential
Heat No.
kPa psi kPa psi
stress in thin-walled tubing may be calculated from the change
in outside diameter that occurs upon splitting a length of the
1 234000 34000 37000 5400
2 272000 39400 52000 7600
tubing. The Hatfield and Thirkell formula, as later modified by
3 217000 31500 30000 4300
SachsandEspey, providesasimplemethodforcalculatingthe
4 183000 26500 52000 7500
approximatecircumferentialstressfromthechangeindiameter 5 241000 34900 59000 8600
6 30000 4300
of straight, thin-walled, metal tubing.
7 59000 8600
1.2 This standard does not purport to address all of the
8 30000 4300
safety concerns, if any, associated with its use. It is the 9 52000 7500
10 37000 5400
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
a titanium condenser tube. This practice provides a means for
estimating the residual stresses in samples from each and every
2. Referenced Documents
heat.
2.1 ASTM Standards:
4.2.1 This practice may also be used to estimate the residual
E 6 Terminology Relating to Methods of Mechanical Test-
stresses that remain in tubes after removal from service in
ing
different environments and operating conditions.
4.3 Thispracticeassumesalinearstressdistributionthrough
3. Terminology
the wall thickness. This assumption is usually reasonable for
3.1 The definitions in this practice are in accordance with
thin-walled tubes, that is, for tubes in which the wall thickness
Terminology E 6.
does not exceed one tenth of the outside diameter. Even in
cases where the assumption is not strictly justified, experience
4. Significance and Use
has shown that the approximate stresses estimated by this
4.1 Residual stresses in tubing may be detrimental to the
practice frequently serve as useful indicators of the suscepti-
future performance of the tubing. Such stresses may, for
bility to stress corrosion cracking of the tubing of certain metal
example, influence the susceptibility of a tube to stress corro-
alloys when exposed to specific environments.
sion cracking when the tube is exposed to certain environ-
4.3.1 Because of this questionable assumption regarding the
ments.
stress distribution in the tubing, the user is cautioned against
4.2 Residual stresses in new thin-walled tubing are very
using the results of this practice for design, manufacturing
sensitivetotheparametersofthefabricationprocess,andsmall
control, or other purposes without supplementary information
variations in these parameters can produce significant changes
that supports the application.
intheresidualstresses.See,forexample,Table1,whichshows
4.4 This practice has primarily been used to estimate re-
the residual stresses measured by this practice in samples from
sidual fabrication stresses in new thin-walled tubing between
successive heats of a ferritic Cr-Mo-Ni stainless steel tube and
19-mm (0.75-in.) and 25-mm (1-in.) outside diameter and
1.3-mm (0.05-in.) or less wall thickness. While measurement
difficulties may be encountered with smaller or larger tubes,
ThispracticeisunderthejurisdictionofASTMCommitteeE-28onMechanical
there does not appear to be any theoretical size limitation on
Testing and is the direct responsibility of Subcommittee E28.13 on Residual Stress
Measurement. the applicability of this practice.
Current edition approved October 10, 1999. Published December 1999. Origi-
nally published as E 1928 - 98. Last previous edition E 1928 - 98.
5. Procedure
Sachs, G. and Espey, G., “A New Method for Determination of Stress
5.1 On new material, the stress determination shall be made
Distribution in Thin-walled Tubing,” Transactions of the AIME, Vol 147, 1942.
Annual Book of ASTM Standards, Vol 03.01. on at least one representative sample obtained from each lot or
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1928
EI 1 1 EI R – R
heat of material in the final size and heat treatment. The results
1 o
M 5 – 5 3 (1)
F G
2 2 2
R R R R
of tests on brass and steel tubes, reported by Sachs and Espey, 1–µ o 1 1–µ o 1
indicate that the length of the sample piece of tube should be
where:
at least three times the outside diameter in order to avoid
E = modulus of elasticity,
significant end effects.
µ = Poisson’s ratio,
5.2 At the midlength of the tube sample, measure the
R = mean outside radius before splitting,
o
outside diameter at four locations (every 45°) around the tube
R = mean outside radius after splitting, and
circumference in order to verify that the cross section is
I = cross-sectional moment of inertia of unit length of
reasonably circular.
tube wall.
5.3 Selectandmarkastraightlinelengthwiseonthesample,
6.2.1 Standard reference book values of the modulus of
indicating where the split will be made. If the tube thickness is
elasticity and Poisson’s ratio may be used for this purpose.
not uniform around the periphery, some practitioners prefer the
6.3 The release of this bending moment corresponds to a
split to be made at the thinnest location.
release of the bending stresses in the section. If the stress
5.4 Determine the average outside diameter, D,ofthe
distribution is such that the stresses vary linearly from one
o
sample by measuring the diameter at 90° to the line where the
surface to the other, then the minimum and maximum stresses
split will be made, and at four equally spaced locations along
occur at the surfaces and are given as follows:
the length, and averaging.Any measuring system may be used
Mt E t R – R
1 o
provided that the measurement uncertainty does not exceed S 5 56 3 3 (2)
2I 2 R R
1– µ o 1
0.013 mm (0.0005 in.) or 0.07 %, whichever is larger. See 5.6
and Note 2.
where:
5.5 Split the sample longitudinally on one side over its full t = av
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