SIST EN ISO 5755:2022

SLOVENSKI STANDARD
oSIST prEN ISO 5755:2022
01-marec-2022
Sintrane kovine - Specifikacije (ISO/DIS 5755:2022)
Sintered metal materials - Specifications (ISO/DIS 5755:2022)
Sintermetallwerkstoffe - Anforderungen (ISO/DIS 5755:2022)
Matériaux métalliques frittés - Spécifications (ISO/DIS 5755:2022)
Ta slovenski standard je istoveten z: prEN ISO 5755
ICS:
77.160 Metalurgija prahov Powder metallurgy
oSIST prEN ISO 5755:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 5755:2022

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oSIST prEN ISO 5755:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 5755
ISO/TC 119/SC 5 Secretariat: UNE
Voting begins on: Voting terminates on:
2022-01-04 2022-03-29
Sintered metal materials — Specifications
Matériaux métalliques frittés — Spécifications
ICS: 77.160
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 5755:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022

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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Sampling . 3
5 Test methods for normative properties . 3
5.1 General . 3
5.2 Chemical analysis . 3
5.3 Open porosity . 3
5.4 Mechanical properties . 3
5.4.1 General . 3
5.4.2 Tensile properties . . 4
5.4.3 Radial crushing strength . 4
6 Test methods for informative properties . 4
6.1 General . 4
6.2 Density . 4
6.3 Tensile strength . 5
6.4 Tensile yield strength . 5
6.5 Elongation . 5
6.6 Young’s modulus. 5
6.7 Poisson’s ratio . 5
6.8 Impact energy . 5
6.9 Compressive yield strength . 5
6.10 Transverse rupture strength . 6
6.11 Fatigue strength . 6
6.11.1 General . 6
6.11.2 Rotating bending fatigue strength . 6
6.11.3 Plane-bending fatigue strength . 6
6.11.4 Axial fatigue strength . 6
6.12 Apparent hardness . . 6
6.13 Coefficient of linear expansion . . 7
7 Specifications . 7
8 Designations . 7
Annex A (normative) Designation system .38
Annex B (informative) Microstructures .41
Annex C (Informative) Equivalence of standards of powder metallurgy materials .54
Bibliography .72
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(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 of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 119, Powder metallurgy, Subcommittee
SC 5, Specifications for powder metallurgical materials (excluding hardmetals).
This fourth edition cancels and replaces the third edition (ISO 5755:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Inclusion of an annex on metallography of sintered materials.
— Inclusion of a table of equivalences of the materials of the standard with the materials of other
international standards of habitual use:
— Materials for bearings.
— Materials for structural parts.
— Copper based materials for structural parts.
— Aluminium for structural parts.
— Soft magnetic materials and new materials.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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oSIST prEN ISO 5755:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 5755:2022(E)
Sintered metal materials — Specifications
1 Scope
This International Standard specifies the requirements for the chemical composition and the
mechanical and physical properties of sintered metal materials used for bearings and structural parts.
When selecting powder metallurgical (PM) materials, it should be taken into account that the properties
depend not only on the chemical composition and density, but also on the production methods. The
properties of sintered materials giving satisfactory service in particular applications may not
necessarily be the same as those of wrought or cast materials that might otherwise be used. Therefore,
liaison with prospective suppliers is recommended.
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 437, Steel and cast iron — Determination of total carbon content — Combustion gravimetric method
ISO 1099, Metallic materials — Fatigue testing — Axial force-controlled method
ISO 1143, Metallic materials — Rotating bar bending fatigue testing
ISO 2738, Sintered metal materials, excluding hardmetals — Permeable sintered metal materials —
Determination of density, oil content and open porosity
ISO 2739, Sintered metal bushings — Determination of radial crushing strength
ISO 2740, Sintered metal materials, excluding hardmetals — Tensile test pieces
ISO 2795, Plain bearings — Sintered bushes — Dimensions and tolerances
ISO 3325, Sintered metal materials, excluding hardmetals — Determination of transverse rupture strength
ISO 3928, Sintered metal materials, excluding hardmetals — Fatigue test pieces
ISO 3954, Powders for powder metallurgical purposes — Sampling
ISO 4498, Sintered metal materials, excluding hardmetals — Determination of apparent hardness and
microhardness
ISO 5754, Sintered metal materials, excluding hardmetals — Unnotched impact test piece
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7625, Sintered metal materials, excluding hardmetals — Preparation of samples for chemical analysis
for determination of carbon content
ISO 14317, Sintered metal materials excluding hardmetals — Determination of compressive yield strength
ASTM E228, Standard Test Method for Linear Thermal Expansion of Solid Materials with a Push-Rod
Dilatometer
ASTM E1875, Standard Test Method for Dynamic Young’s Modulus, Shear Modulus, and Poisson’s Ratio by
Sonic Resonance
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
IEC 60404-8-9, Magnetic materials — Part 8: Specifications for individual materials - Section 9: Standard
specification for sintered soft magnetic materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
tensile strength
R
m
ability of a test specimen to resist fracture when a pulling force is applied in a direction parallel to its
longitudinal axis – expressed in MPa
Note 1 to entry: It is equal to the maximum load divided by the original cross-sectional area.
3.2
tensile yield strength
R
p0,2
load at which the material exhibits a 0,2 % offset from proportionality on a stress-strain curve in
tension, divided by the original cross-sectional area – expressed in MPa
3.3
Young’s modulus
E
ratio of normal stress to corresponding strain for tensile or compressive stresses below the proportional
limit of the material – expressed in GPa
3.4
Poisson’s ratio
v
absolute value of the ratio of transverse strain to the corresponding axial strain, resulting from
uniformally distributed axial stress below the proportional limit of the material
3.5
impact energy
measurement of the energy absorbed when fracturing a specimen with a single blow – measured in
Joules (J)
3.6
compressive yield strength
stress at which a material exhibits a specified permanent set – expressed in MPa
3.7
transverse rupture strength
stress, calculated from the bending strength formula, required to break a specimen of a given dimension
– expressed in MPa
3.8
fatigue strength
maximum alternating stress that can be sustained for a specific number of cycles without failure, the
stress being reversed with each cycle unless otherwise stated – expressed in MPa
3.9
radial crushing strength
radial stress required to fracture a hollow cylindrical part of specified dimensions – expressed in MPa
3.10
density
3
mass per unit volume of the material – expressed in g/cm
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
3.11
apparent hardness
resistance of a powder metallurgical (PM) material to indentation, tested under specified conditions;
for PM materials, it is a function of the density of the material
3.12
open porosity
oil content after full impregnation, divided by the volume of the test piece, and multiplied by 100 –
expressed as a volume percentage
3.13
coefficient of linear expansion
−6 −1
change in length per unit length per degree change in temperature – expressed in 10 K
4 Sampling
Sampling of powders to produce standard test pieces shall be carried out in accordance with ISO 3954.
5 Test methods for normative properties
5.1 General
The following test methods shall be used to determine the normative properties given in Tables 1 to 18.
5.2 Chemical analysis
The chemical composition table for each material lists the principal elements by minimum and
maximum mass percentage before any additional process, such as oil impregnation, resin impregnation
or steam treatment, has taken place. “Other elements” may include minor amounts of elements added
for specific purposes and is reported as a maximum percentage.
Whenever possible, and always in cases of dispute, the methods of chemical analysis shall be those
specified in the relevant International Standards. If no International Standard is available, the method
may be agreed upon and specified at the time of enquiry and order.
Samples for the determination of total carbon content shall be prepared in accordance with ISO 7625.
Determination of the total carbon content shall be in accordance with ISO 437.
5.3 Open porosity
The open porosity shall be determined in accordance with ISO 2738.
5.4 Mechanical properties
5.4.1 General
The as-sintered mechanical properties given in Tables 1 to 18 were determined on pressed and sintered
test pieces with a mean chemical composition. The heat-treated mechanical properties given in Tables 1
to 18 were determined on test bars which were either pressed and sintered or machined from pressed
and sintered blanks. They are intended as a guide to the initial selection of materials (see also Clause 1).
They may also be used as a basis for specifying any special tests that may be indicated on the drawing.
The mechanical properties shall neither be calculated from hardness values nor be determined on
tensile test pieces taken from a component and used for verifying the values given in Tables 1 to 18.
If the customer requires that a specified level of mechanical properties be obtained by tests on the
component, these shall be agreed with the supplier and shall be stated on the drawing and/or any
technical documentation of the customer referred to on the drawing.
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
5.4.2 Tensile properties
The ultimate tensile strength and the yield strength shall be determined in accordance with ISO 2740
and, ISO 6892-1. For heat-treated materials, tensile strength and yield strength are approximately equal
and, in this case, tensile strength is specified.
The normative yield strengths (as-sintered condition) and ultimate tensile strengths (heat-treated
condition) are shown as minimum values. These strengths may be used in designing PM part
applications. To select a material which is optimum in both properties and cost-effectiveness, it is
essential that the part application be discussed with the PM parts manufacturer.
The minimum values were developed from tensile specimens prepared specifically for evaluating PM
materials.
Tensile specimens machined from commercial parts may differ from those obtained from prepared
tensile specimens. To evaluate the part strength, it is recommended that static or dynamic proof-testing
be agreed between the purchaser and the manufacturer and carried out on the first production lot of
parts. The results of testing to failure can be used statistically to determine a minimum breaking force
for future production lots.
Acceptable strength can also be demonstrated by processing tensile specimens prepared specifically
for evaluating PM materials manufactured from the same batch of powder as the production parts and
processed with them.
As indicated above, the testing of test bars machined from the PM component is the least desirable
method for demonstrating minimum properties.
For heat-treated properties, the test bars were quench-hardened and tempered to increase the
strength, hardness and wear resistance. Tempering is essential to develop the properties given
in this International Standard. Heat-treat equipment that utilizes a gas atmosphere or vacuum is
recommended. The use of liquid salts is not recommended due to entrapment of the salts in the porosity
causing “salt bleed-out” and “internal corrosion”. Some materials may be heat-treated directly after the
sintering process by controlling the cooling rate within the sintering furnace. This process is usually
known as “sinter hardening”. Materials processed by this route also require tempering to develop their
optimum strengths.
5.4.3 Radial crushing strength
The radial crushing strength shall be determined in accordance with ISO 2739. The wall thicknesses of
test pieces to be used shall be in the range covered by ISO 2795. For test pieces outside this range, the
specified radial crushing strength values are different and shall be agreed between the customer and
the supplier.
6 Test methods for informative properties
6.1 General
Typical values are given for each material; these include tensile and yield strengths. These typical
values are given for general guidance only. They should not be used as minimum values.
These typical properties should be achievable through normal manufacturing processing. Again,
any specific tests on components should be discussed and agreed between the purchaser and the
manufacturer.
6.2 Density
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Density is expressed in grams per cubic centimetre (g/cm ). The density shall be determined in
accordance with ISO 2738. Density is normally determined after the removal of any oils or non-metallic
materials from the porosity and is known as the “dry density”. The “wet density” is sometimes reported
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
on production bearings or parts, this is the mass per unit volume, including any oil or non-metallic
material that has impregnated the component.
6.3 Tensile strength
The tensile strength shall be determined in accordance with ISO 2740 and ISO 6892-1.
6.4 Tensile yield strength
The tensile yield strength shall be determined in accordance with ISO 2740 and ISO 6892-1.
6.5 Elongation
Elongation (plastic) shall be determined in accordance with ISO 6892-1. It is expressed as a percentage
of the original gauge length (usually 25 mm), and is determined by on measuring the increase in gauge
length after the fracture, providing the fracture takes place within the gauge length. Elongation can
also be measured with a break-away extensometer on a tensile specimen. The recorded stress/strain
curve displays total elongation (elastic and plastic). The elastic strain must be subtracted from the
total elongation to give the plastic elongation (this can sometimes be provided with the test machine’s
software).
6.6 Young’s modulus
Young’s modulus shall be determined in accordance with ASTM E1875. Data for the elastic constants in
this International Standard were generated from resonant frequency testing. An equation relating the
three elastic constants is:
vE= /21G − (1)
()
where
v is Poisson’s ratio;
E is Young’s modulus;
G is the shear modulus.
6.7 Poisson’s ratio
Poisson’s ratio shall be determined in accordance with ASTM E1875.
6.8 Impact energy
The impact energy shall be determined in accordance with ISO 5754. The data in this International
Standard were obtained using an unnotched Charpy specimen.
6.9 Compressive yield strength
The compressive yield strength shall be determined in accordance with ISO 14317. For certain heat-
treated materials listed in the tables, the hardenability is not sufficient to completely through-harden
the 9,00 mm diameter test specimen. Due to variation in hardenability among the heat-treated steels
listed in the tables, the compressive yield strength data are appropriate only for 9,00 mm sections.
Typically, smaller cross-sections have higher compressive yield strengths and larger sections have
somewhat lower strengths due to the hardenability response. Since the cross-section of the tensile
yield test specimen is smaller than the compressive yield specimen, a direct correspondence between
tensile and compressive yield strength data are not possible.
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oSIST prEN ISO 5755:2022
ISO/DIS 5755:2022(E)
6.10 Transverse rupture strength
The transverse rupture strength shall be determined in accordance with ISO 3325.
The strength formula in ISO 3325 is strictly valid only for non-ductile materials; nevertheless, it is
widely used for materials that bend at fracture and is useful for establishing comparative strengths.
Data for such materials are included as typical properties in ISO 3325.
6.11 Fatigue strength
6.11.1 General
The number of cycles survived should be stated with each strength listed.
7
For PM ferrous materials, like wrought ferrous materials, fatigue strengths of 10 cycles in duration
using unnotched specimens are considered to be sustainable indefinitely and are therefore considered
to be fatigue limits (also termed endurance limits). By contrast, non-ferrous PM materials do not have
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10 cycle maximum fatigue strengths sustainable for indefinite times and these stress limits therefore
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simply remain as the fatigue strength at 10 cycles.
The fatigue limits in this International Standard were generated through statistical analysis of the
test data. Due to the limited number of data points available for the analysis, these fatigue strengths
were determined as the 90 % survival stress, i.e. the fatigue stress at which 90 % of the test specimens
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survived 10 cycles.
There are three methods of stressing the test specimens and each gives different fatigue strengths.
These are described in 6.11.2 to 6.11.4.
6.11.2 Rotating bending fatigue strength
This test method uses a machined, round, smooth test specimen (in accordance with ISO 3928), with
an R. R. Moore testing machine. Testing is conducted in accordance with ISO 1143. The specimen is
held at one end and rotated while it is stressed at the other end. The surface of the test bar is the most
highly stressed area and the centre line has a neutral stress. This test method gives the highest fatigue
strength.
6.11.3 Plane-bending fatigue strength
This method used for plane-bending fatigue uses a standard sintered fatigue test bar (in accordance
with ISO 3928) that is subjected to an alternating stress. This test method gives a slightly lower fatigue
strength than the rotating bending fatigue test, as more of the cross-sectional area is subjected to the
stress. Evaluation of fatigue strength is done according to the staircase method described in MPIF
Standard 56.
6.11.4 Axial fatigue strength
This method uses either a machined, round or standard sintered fatigue test bar (in accordance
with ISO 3928) that is tested in a test machine by clamping both ends and subjecting the test bar to
alternating stresses where R = −1. Testing is conducted in accordance with ISO 1099. As the whole of the
cross-section is stressed, this test method gives the lowest fatigue strength.
6.12 Apparent hardness
The apparent hardness shall be determined in accordance with ISO 4498. The hardness value of a
PM part when using a conventional indentation hardness tester is referred to as “apparent hardness”
because it rep
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