ISO 7148-1:2012

SLOVENSKI STANDARD
01-marec-2015
1DGRPHãþD
SIST ISO 7148-1:2002
Drsni ležaji - Preskušanje materialov za drsne ležaje glede na tribološke lastnosti -
1. del: Preskušanje kovin za ležaje
Plain bearings - Testing of the tribological behaviour of bearing materials - Part 1:
Testing of bearing metals
Paliers lisses - Essai du comportement tribologique des matériaux antifriction - Partie 1:
Essai des matériaux métalliques
Ta slovenski standard je istoveten z: ISO 7148-1:2012
ICS:
21.100.10 Drsni ležaji Plain bearings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 7148-1
Third edition
2012-10-01
Plain bearings — Testing of the
tribological behaviour of bearing
materials —
Part 1:
Testing of bearing metals
Paliers lisses — Essai du comportement tribologique des matériaux
antifriction —
Partie 1: Essai des matériaux métalliques
Reference number
©
ISO 2012
© ISO 2012
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Published in Switzerland
ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Symbols and units . 1
4 Special features for the tribological testing of metallic bearing materials .2
5 Test methods . 2
5.1 Test method A — Pin-on-disc . 2
5.2 Test method B — Block-on-ring . 3
5.3 Test method C — Rotation under thrust load . 4
6 Test specimens. 5
6.1 Disc . 5
6.2 Ring . 5
6.3 Pin . 5
6.4 Block. 5
6.5 Sleeve . 5
6.6 Plate . 6
6.7 Preparation of the test specimens . 6
7 Test methods and test equipment . 7
8 Lubrication . 7
9 Designation . 7
10 Test conditions . 7
11 Test procedure . 8
Annex A (informative) Test report . 9
Bibliography .11
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
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.
ISO 7148-1 was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 2,
Materials and lubricants, their properties, characteristics, test methods and testing conditions.
This third edition cancels and replaces the second edition (ISO 7148-1:1999), which has been
technically revised.
ISO 7148 consists of the following parts, under the general title Plain bearings — Testing of the tribological
behaviour of bearing materials:
— Part 1: Testing of bearing metals
— Part 2: Testing of polymer-based bearing materials.
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 7148-1:2012(E)
Plain bearings — Testing of the tribological behaviour of
bearing materials —
Part 1:
Testing of bearing metals
1 Scope
This part of ISO 7148 specifies tribological tests of metallic bearing materials for plain bearings under
conditions of boundary lubrication.
The test procedures described in this part of ISO 7148 enable the friction and wear behaviour of
bearing material/mating/lubricant combinations to be compared with that of other combinations,
thus facilitating the selection of a bearing material for running repeatedly or for long periods under
conditions of boundary lubrication, low speed and continuous sliding. Owing to differences in test
conditions, measured friction and wear values can be expected to vary from one test facility to another.
The test results give useful information for practical application only if all parameters of influence are
identical. The more the test conditions deviate from the actual application, the greater the uncertainty
of the applicability of the results.
2 Normative references
The following referenced documents are indispensable for the application 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 4385, Plain bearings — Compression testing of metallic bearing materials
3 Symbols and units
See Table 1.
Table 1 — Symbols and units
Symbol Term Unit
A, B, C Test method —
a Sliding distance km
A Elongation at fracture %
Coefficient of friction; ratio between friction force and normal force, i.e.:
F
f
f —
f =
F
n
F Friction force N
f
F Normal force N
n
K Overlap ratio (area of contact divided by area of wear track) —
A
Table 1 (continued)
Symbol Term Unit
Coefficient of wear, volumetric wear rate related to the normal force, i.e.:
V w
w v
K mm /(N · km)
w
K = =
w
F ×a F
n n
l Linear wear as measured by change in distance mm
w
m Mass of material removed by wear g
w
Ra Surface roughness µm
R Compression limit 0,2 % N/mm
d0,2
R Tensile strength N/mm
m
R 0,2 % Proof stress N/mm
p0,2
Specimen’s temperature near the sliding surface during testing under steady-
T °C
state conditions
T Ambient temperature °C
amb
T Lubricant temperature °C
L
t Test duration h
Ch
U Sliding velocity m/s
V Material removed by wear as measured by change in volume mm
w
l
w
w Linear wear rate, i.e.: w = mm/km
l l
a
V
w
Volumetric wear rate, i.e.: w =
w mm /km
v
v
a
η Lubricant viscosity mPa · s
4 Special features for the tribological testing of metallic bearing materials
Plain bearings made of metallic materials usually require lubrication (e.g. oil or grease) to ensure a low
rate of friction and wear.
If possible, lubricated plain bearings should be designed to run under hydrodynamic conditions, where
the sliding surfaces of the journal and the plain bearing are always fully separated by a film of lubricant.
Under such conditions, friction depends on the rheological properties of the lubricant, and wear normally
does not occur.
If hydrodynamic operation cannot be ensured, boundary lubrication prevails and wear of the bearing
and mating material is likely. This may be during the starting or running down phase of a hydrodynamic
plain bearing or when high loads, low sliding
...