ISO 15461:2018

Steel forgings — Testing frequency, sampling conditions and test methods for mechanical tests

ISO 15461:2018 gives guidelines for the simplification and harmonization of the specifications for mechanical testing of open die and closed die forgings in International Standards and other technical delivery conditions for forgings of steel. ISO 15461:2018 a) offers various options for the frequency of testing, and sampling conditions, b) introduces a designation system for the options, mentioned under (a), and c) specifies the test methods for room temperature tensile tests, elevated temperature tensile tests, impact tests, and uniformity checks by hardness tests.

Pièces forgées en acier — Fréquence des essais, conditions d'echantillonnage et méthodes d'essai pour essais mécaniques

General Information

• Status: Published
• Publication Date: 31-Jan-2018
• ICS: 77.040.10 - Mechanical testing of metals
• ICS: 77.140.85 - Iron and steel forgings
• Technical Committee: ISO/TC 17/SC 10 - Steel for pressure purposes
• Drafting Committee: ISO/TC 17/SC 10 - Steel for pressure purposes
• Current Stage: 9060 - Close of review
• Start Date: 02-Sep-2028

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15461
First edition
2018-01
Steel forgings — Testing frequency,
sampling conditions and test methods
for mechanical tests
Pièces forgées en acier — Fréquence des essais, conditions
d'echantillonnage et méthodes d'essai pour essais mécaniques
Reference number
ISO 15461:2018(E)
©
ISO 2018

---------------------- Page: 1 ----------------------
ISO 15461:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 15461:2018(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 2
5 Testing frequency . 3
6 Uniformity checks on test units by hardness tests . 6
7 Sampling conditions . 7
8 Designation and determination of the direction of the test piece axis .16
8.1 General .16
8.2 Designation for the main direction of strain during forming .16
8.3 Determination of X, Y and Z .17
9 Test methods .20
9.1 Tensile test at room temperature .20
9.2 Impact tests .20
9.3 Verification of the elevated temperature proof strength .21
Annex A (informative) Presentation of the specifications for the testing frequency and
the sampling conditions in tabulated form .22
Bibliography .24
© ISO 2018 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 15461:2018(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 10 Steel for
pressure purposes.
This first edition of ISO 15461 is based on Technical Report ISO/TR 15461:1997, which has been
withdrawn. The main changes are as follows:
— Figures 3 a) and b) have been revised;
— Table 3 has been revised;
— Table 5 has been extended to steels for pressure purposes;
— the text of the document has been generally revised.
iv © ISO 2018 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 15461:2018(E)
Steel forgings — Testing frequency, sampling conditions
and test methods for mechanical tests
1 Scope
This document gives guidelines for the simplification and harmonization of the specifications for
mechanical testing of open die and closed die forgings in International Standards and other technical
delivery conditions for forgings of steel.
This document
a) offers various options for
1) the frequency of testing, and
2) sampling conditions,
b) introduces a designation system for the options, mentioned under (a), and
c) specifies the test methods for
1) room temperature tensile tests,
2) elevated temperature tensile tests,
3) impact tests, and
4) uniformity checks by hardness tests.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 377:2017, Steel and steel products — Location and preparation of samples and test pieces for
mechanical testing
ISO 404, Steel and steel products — General technical delivery requirements
ISO 3785, Metallic materials — Designation of test specimen axes in relation to product texture
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 6892-2, Metallic materials – Tensile testing at elevated temperature — Part 2: Method of test at
elevated temperature
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
© ISO 2018 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 15461:2018(E)

— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
specific inspection and testing
inspection and testing carried out before delivery, according to the technical requirements of the order,
on the products to be supplied or on test units of which the product supplied is part, in order to verify
whether these products comply with the requirements of the order
[SOURCE: ISO 404:2013, 3.4, modified — “and testing” has been added and the wording has been
altered.]
3.2
test unit
number of pieces or the tonnage of products to be accepted or rejected together, on the basis of the tests to
be carried out on sample products in accordance with the requirements of the product standard or order
[SOURCE: ISO 404:2013, 3.6, modified — the wording has been altered slightly and the notes to entry
have been deleted.]
3.3
sample product
item (e.g. bar, sheet, coil) selected for inspection or testing
[SOURCE: ISO 377:2017, 3.2]
3.4
sample
sufficient quantity of material taken from the sample product for the purpose of producing one or more
test pieces
Note 1 to entry: In certain cases, the sample can be the sample product.
[SOURCE: ISO 377:2017, 3.3, modified — a note to entry has been deleted.]
3.5
test piece
part of a sample, with specified dimensions, machined or unmachined, brought to a required condition
for submission to a given test
[SOURCE: ISO 377:2017, 3.5, modified — the wording has been altered slightly and a note to entry has
been deleted.]
Note 1 to entry: In certain cases the test piece can be the sample.
3.6
ruling section
section for which the mechanical properties are specified
4 General
Unless otherwise specified in this document, the general conditions given in ISO 377 for the marking
and preparation of samples and test pieces apply.
Where the conditions specified in this document differ from the conditions specified in the product
standard or order, then the conditions of the product standard or order apply.
2 © ISO 2018 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 15461:2018(E)

5 Testing frequency
5.1 For the testing frequency of room temperature tensile tests and of impact tests, the requirements
given in 5.1.1 to 5.1.3 apply.
5.1.1 The product standard or order shall specify, by reference to the appropriate symbol(s) in Table 1,
column 1, the following:
a) the composition of the test unit as defined in Table 1, columns 2 to 8;
b) whether uniformity checks by hardness tests in accordance with Table 1, column 9 are required
and, if so, the percentage of products to be subjected to the hardness tests;
c) the number of sample products to be taken from the test unit. (See the explanations in Table 1,
a
footnote , for replacing the letter “n” of the symbol by the mass of the test unit up to which the
taking of one sample product is sufficient.)
NOTE Less stringent requirements for the composition of the test unit can be compensated by more stringent
requirements for the number of sample products to be tested. Therefore, for example, a test unit characterized by
the symbol CH5 can be regarded as equivalent to a test unit characterized by the symbol CHD10 or CFHD15 and
the test unit CU100 can be regarded as equivalent with CFHDU10. Consequently, it seems possible and reasonable
to specify in the product standards or orders not only one distinct test unit, but to leave various equivalent test
units to the choice of the manufacturer or to an agreement at the time of enquiry and order, as shown in the
example in Table A.1, column 5.
5.1.2 In general one sample is to be taken per sample product. The product standard or order may,
however, by reference to the symbols in Table 2, specify that in the case of products with a length and/or
mass greater than a certain limiting value two samples per sample product shall be taken.
5.1.3 If room temperature tensile tests are to be carried out, one tensile test piece shall be taken per
sample. If impact tests are to be carried out, three impact test pieces shall be taken per sample.
5.2 If elevated temperature tensile tests are to be carried out, the product standard or order shall
specify the number of test pieces to be taken for this test in relation to the number of test pieces to be
taken for the room temperature tensile test (see example in Table A.1, column 9).
5.3 For simplifying comparisons the data for the frequency of testing should preferably be specified in
the form of a table. (See the example in Table A.1.)
© ISO 2018 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 15461:2018(E)

4 © ISO 2018 – All rights reserved
Table 1 — Options for the test units, the number of sample products to be taken per test unit and the percentage of products to be
subjected to hardness tests for uniformity checks
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Test unit The test unit shall be composed of products The test Number of sample products to be taken Notes
symbol unit shall from test units with an as heat-treated
have been weight of
subjected
to
a
of the same forming having been subjected to ≤ n > n > 2n > 4n > 8n
≤ 2n ≤ 4n ≤ 8n ≤ 16n
b c
of the process cycle of the same of similar the same the same
d e
same shape and shape and type conditions
cast dimensions dimensions of heat of heat
x tonnes
treatment treatment
a a a a a a
tu C F D H Ux
In general not for quenched and
Cn x x — — x x — — 1 2 3 4 5
tempered products
CHn x x — — x x —
x
CHDn x x — x — x — 1 2 3 4 5 —
x
CFHDn x x x x — x —
CUx x x — — x x —
Only applicable where the test pieces
Independent from the weight of the test
CHUx x x — — x x x
for the mechanical tests can be taken
unit, two sample products, namely the
from the products themselves (no
CHDUx x x — x — x x an %
hardest and softest, shall be tested.
prolongations)
uniformity
CFHDUx x x x x — x x
check by
hardness
CnUx x x — — x x — Normally only applied where, for the
tests (see
tensile and impact tests, prolonga-
CHnUx x x — — x x x
Clause 6)
tions or integral surplus-material is
1 2 3 4 5
provided. The product standard shall,
CHDnUx x x — x — x x
in this case, include specifications for
CFDnH x x x x — x x
the maximum hardness range
IND The test unit sample product shall consist of the individual forging Not for small products

---------------------- Page: 8 ----------------------
ISO 15461:2018(E)

© ISO 2018 – All rights reserved 5
Table 1 (continued)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Test unit The test unit shall be composed of products The test Number of sample products to be taken Notes
symbol unit shall from test units with an as heat-treated
have been weight of
subjected
to
a
of the same forming having been subjected to ≤ n > n > 2n > 4n > 8n
≤ 2n ≤ 4n ≤ 8n ≤ 16n
b c
of the process cycle of the same of similar the same the same
d e
same shape and shape and type conditions
cast dimensions dimensions of heat of heat
x tonnes
treatment treatment
a a a a a a
tu C F D H Ux
a
  The symbols for the test unit in column 1 and in the headings of columns 2 to 10 have the following meaning:
tu  test unit;
C  products of the same cast;
F  same forming cycle;
D  same shape and dimensions;
H  same heat treatment conditions.
n  in the product standard or order, the letter n of the symbol for the test unit given in column 1 is to be replaced by the mass of the test unit in tonnes up to which, in accordance with the indications in
column 10, the testing of one sample product is sufficient. (For n the values 5, 10, 20 and 40 is preferred.)
Ux  for checking the uniformity of the test unit, x % of the products and at least the number of products given in Table 3 are to be subjected to a hardness test.
EXAMPLE
The symbol CHD10 would, in accordance with the indications in columns 2 to 15, mean the following:
The test unit covers products of the same cast and the same dimensions and has been subjected to the same heat treatment condition. If the weight of the test unit is 10 t one sample product is to be
tested; if its weight is > 4 n but ≤ 8 n, (that means in this example > 40 t but ≤ 80 t) four samples are to be tested.
b
  Forgings are regarded as being taken from the same forming cycle when they were, without any essential interruption, manufactured one after the other by the same forming process under the same
conditions or, in other words, when they were produced in series.

---------------------- Page: 9 ----------------------
ISO 15461:2018(E)

Table 2 — Conditions for taking two samples per sample product
Symbols
Conditions for taking two samples per sample
b
a product
in general numbers example
Forgings with a length or greatest dimension greater than y
ly l5
(5) metres.
Forgings with an as heat treated individual weight greater
wz w4
than z (4) tonnes.
Forgings with a length or greatest dimension greater than y
ly+wz l5+w4 (5) meters and an as heat treated individual weight greater
than z (4) tonnes.
Forgings with a length or greatest dimension greater than y
ly or wz l5 or w4 (5) meters or an as heat treated individual mass greater than
z (4) tonnes.
a
Replace as shown in the column “example” the letter y in the symbol by the appropriate value for the length in meters
and the letter z by the appropriate value for the as heat treated individual mass of the forgings in tonnes.
b
The values given in parentheses apply for the example given in column 2.
6 Uniformity checks on test units by hardness tests
All test units bearing as last letter in their symbol a “U” followed, as indicated in Table 1, by a value x = 5
to 100 shall be subjected as follows to uniformity checks by hardness tests.
Depending on the value of x, given in the symbol for the test unit, the number of products stated in
Table 3 shall be selected at random for the hardness tests.
Table 3 — Number of products to be checked
a,b
x Number of products to be checked
5
10
20
100 %
30
50
100
a
For x the values given above should be used.
b
For test units of the type CU high values of x are normally specified,
whereas for the more homogeneous test units of the type CHU, CHDU
and CFHDU, lower values are normally applied.
On all products to be hardness tested, the same location shall be tested. This location shall lie at the
surface of the product and where possible in an area where the thickness of the product corresponds to
the thickness of the ruling section.
Decarburized zones and, as far as it may impair the measurement, scale shall be eliminated before the
hardness tests are carried out.
All hardness tests on the products of one test unit shall be carried out using to the same method. If the
hardness test method is not specified in the product standard or order, the manufacturer may choose
the method. Acceptable methods are as follows:
a) Brinell test in accordance with ISO 6506-1;
6 © ISO 2018 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 15461:2018(E)

b) Vickers test in accordance with ISO 6507-1;
c) Rockwell test in accordance with ISO 6508-1;
d) Shore test in accordance with ASTM E448 or JIS Z 2246;
e) “Leeb” test in accordance with ISO 16859-1 or ASTM A956.
7 Sampling conditions
The product standard or order shall, preferably in the form of a table (see example in Table A.2), specify
the following:
a) by reference to the symbols in Table 4, the type of sample product and, where surplus material is
required, the way of mounting this;
b) by reference to the symbols in Table 5, the distance of the test piece axis from the surface of the
sample product in the as heat treated condition;
c) by reference to the symbols in Table 6, the direction of the longitudinal test piece axis and, in
the case of impact test pieces, the direction of the notch of the test piece and the fracture plane
determined by this to the direction of grain flow or strain.
Table 4 — Options for the types of sample products (ts) and the positioning of prolongations,
integral surplus material and heat buffers and the location of the test pieces
Symbol Type of sample Description of the type of sample product, the positioning
Notes
ts product of surplus material and the location of test pieces
a
the product is destroyed
The sample product consists of
pl
by taking of the test pieces
a complete product without
Complete products
prolongation or integral surplus
the test pieces are taken
pc
material
by core drilling
b
ppl Figure 1 a)
ppld d in Figure 1 a)
pple e in Figure 1 a)
b, c
pp2 Figure 1 b)
Complete product with The prolongation shall be
prolongations positioned as indicated
pp2d d in Figure 1 b)
pp2e e in Figure 1 b)
pp2f f in Figure 1 b)
pp0 in the order
b
pi1 in Figure 2 a)
Complete product with
The integral surplus material shall
b, c
pi2 integ
...