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ISO/WD 4386-1
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ISO/WD 4386-1
Contents
Page
Foreword............................................................................................................................................................ iv
Introduction ........................................................................................................................................................ v
1
Scope ..................................................................................................................................................... 1
2
Normative references ........................................................................................................................... 1
3
Symbols ................................................................................................................................................. 2
4
4.1
4.2
4.3
Test equipment ..................................................................................................................................... 2
Ultrasonic test device........................................................................................................................... 2
Transducer.......................................................................................... Fehler! Textmarke nicht definiert.
Time base range................................................................................. Fehler! Textmarke nicht definiert.
5
5.1
5.2
Preparation ............................................................................................................................................ 2
Preparation of test surface (sliding surface) ..................................................................................... 2
Ultrasonic scanning.............................................................................................................................. 2
6
Test classes........................................................................................................................................... 3
7
Defect groups ........................................................................................................................................ 3
8
8.1
8.2
Testing ................................................................................................................................................... 3
Back-wall echo testing ......................................................................................................................... 4
Testing without a back-wall echo........................................................................................................ 4
9
9.1
9.2
Evaluation .............................................................................................................................................. 8
Marking of defective areas................................................................................................................... 8
Permissible limits of defects ............................................................................................................... 8
9
10
Designation............................................................................................................................................ 8
9
11
Test report ............................................................................................................................................. 8
9
2
2
3
4
Bibliography ..................................................................................................................................................... 10
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ISO/WD 4386-1
ISO/WD 4386-1
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 4386-1 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 second edition cancels and replaces the first edition (ISO 4386-1:1982), which has been technically revised.
ISO 4386 consists of the following parts, under the general title Plain bearings — Metallic multilayer plain
bearings:

Part 1: Non-destructive ultrasonic testing of bond

Part 2: Destructive testing of bond for bearing metal layer thicknesses greater than or equal to 2 mm

Part 3: Non-destructive penetrant testing
Annex A of this part of ISO 4386 is for information only.
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iv
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WORKING DRAFT
WORKING DRAFT
ISO/WD 4386-1
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ISO/WD 4386-1
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Plain bearings — Metallic multilayer plain bearings — Part 1:
Non-destructive ultrasonic testing of bond
1
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Scope
This part of ISO 4386 specifies an ultrasonic testing method for determining bond defects between the bearing
metal and the backing. The test can be performed on metallic multilayer plain bearings consisting of steel or
copper based material backings lined with bearing metal based on lead and tin, with layer thicknesses greater
than or equal to 0,5 mm. For cast iron backings this standard is not applicable.
Not for cast iron
backing
Backing material:
The ultrasonic testing is not possible on edge zones of sliding surface at flange sides, joint areas,, oil holes,
grooves, etc. in an range of less than half the diameter of the ultrasonic transducer because of undefined reflections. Same apply to bearings with dovetail keying grooves at the bond The ultrasonic testing of bond does
not apply along the edges of the dovetails. Evaluation of the bond between the bearing backing and bearing
material on the end faces and joint faces is possible by the penetrant testing method specified in ISO 4386-3.
Steel
Copper
Not for dovetails
This part of ISO 4386 only describes in detail the pulse-echo method.
Within the meaning of this part of ISO 4386, the ultrasonic method only permits a qualitative evaluation of the
bonding and not a quantitative determination of the bond strength as specified in ISO 4386-2. The ultrasonic
bond test differs only between bond and bond defect.
The sound energy reflected by the bond surface area between the bearing metal and the backing is used to
determine bond defects.
2
Terms of differentiation:
Bond
Bond defect
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.
Has to be
checked whether this standard
applies
ISO 2400:1972, Welds in steel — Reference block for the calibration of equipment for ultrasonic examination
ISO 4386-2:1982, Plain bearings — Metallic multilayer plain bearings — Part 2: Destructive testing of bond for
bearing metal layer thicknesses greater than or equal to 2 mm
Penetration Test-
ISO 4386-3
ing
ISO 4386-3:1982, Plain bearings — Metallic multilayer plain bearings — Part 3: Non-destructive penetrant
testing
Has to be
checked whether this standard
applies
ISO 7963:1985, Welds in steel — Calibration block No. 2 for ultrasonic examination of welds
Standards for
backing materials steel and copper have tobe added!
ISO 6280 ….
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ISO/WD 4386-1
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Symbols
The following symbols are used on the figures in this part of ISO 4386.
IS
Input signal
BE
Bond echo
WE
Back-wall echo
RE
Reference echo
4
Test equipment
4.1
Ultrasonic test device
Pulse-echo ultrasonic equipment using rectified A-scope presentation shall be used for the test. The equipment shall be fitted with a calibrated attenuator, reading in decibels, and adjustable time base ranges. Suppression and swept-gain functions shall be switched off.
Term: Transducer
4.2
Transducer
For standard procedure vertical transducers shall be chosen with size and frequency in relation to the thickness of the bearing layer, backing thickness and backing material. The typical range is from 24 mm diameter,
2 MHz to 6 mm diameter, 10 MHz. For layer thickness < 1mm testing with double transducer may be favourably.
4.3
Definition as a replacement
for Table 1
“Time base range” is not a
proper subtitle for” Test equipment”
Reference piece
The time base range shall be adjusted using reference pieces corresponding to the thicknesses of the bearing
to be inspected.
This explanation is valid for
all procedures (with/without back-wall)
In practice most tests will
be done with “single crystal” vertical transducer. They are in use with different diameter and frequencies.
5
The “twin crystal” = double transducer is
an exception.
Preparation
5.1
5.1.1
The table gives the impression, that single
crystal is for low frequency and twin crystal
for high frequency and that twin crystals
are more in use. That is not true.
Therefore the table has been deleted because it gives no significant info. The text
gives sufficient info.
Preparation of test surface (sliding surface)
Condition of test surface
The test surface shall have a surface roughness of Ra ≤ 5 µm.
5.1.2
Cleaning of test surface
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After machining, remove dirt and oil using suitable cleaning agents. When necessary, the surface may be
dried using cleaning paper or rags.
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5.2
small bearings
Test plain bearings using either contact scanning with light machine oil as a couplant, or using immersion
scanning. Bearings with smaller diameters may de difficult to inspect by contact scanning from the bearing
metal side because of limited access of the ultrasonic transducer. In such case contact scanning from the
back surface may be used under consideration of preconditions Chapter 8 and analogously to Chapter 8.1
2
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In sequence of priority for
Ultrasonic scanning
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At first is the problem with access.
The curved surface is secondary and the
transducer with special curved surface is
an exception.
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ISO/WD 4386-1
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ISO/WD 4386-1
6
Test classes
The test may be carried out in accordance with one of the following three classes, which are of increasing severity.

Class 1: complete coverage of the testable area of the edge zones of the sliding surface at flange sides
and joint areas; point-type coverage of the sliding surface.

Class 2: complete coverage of the testable area of the edge zones of the sliding surface at flange sides
and joint areas. In addition, complete coverage of the area of maximum loading (for example, in the case
of a radial bearing with a bearing force acting vertically downwards, this would be in the range from 60° to
120° with respect to the sliding surface.

Class 3: complete coverage of the testable area of of the flange areas and sliding surface line-by-line. In
order to cover all points, testing is done with an overlap of the lines of 20 % of the transducer diameter.
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Defect groups
The defect groups depend of the strains to which the plain bearing is subjected when in operation and are
classified as follows (see Table 2:


Defect group A: applicable to the new manufacture of plain bearings with steel backings having a wall
thickness up to 70 mm, without voids and bores and with no interruptions in the lined area. For all radial
bearings the defect group A is limited to a surface are of 150.000 mm². For halve bearings the area is restricted to the loaded bearing halve. For radial segments the area has to be distributed to the high loaded
segments. For thrust bearings the defect group A is limited to a surface area of 15.000 mm² for each
segment. The variation of the wall thickness shall not exceed 25 %.
Defect groups B1 and B2: applicable to the new manufacture of plain bearings with steel backings having a wall thickness up to 70 mm without voids and bores and with no interruptions in the lined area. The
variation of the wall thickness shall not exceed 50 %.

Defect group C: applicable to the new manufacture and repair of plain bearings with steel backings having a wall thickness up to 100 mm (if necessary, with voids, bores and interruptions in the lined area). the
variation of the wall thickness shall not exceed 50 %.

Defect group D: applicable to the new manufacture and repair of plain bearings which cannot be classified as belonging to defect groups A, B or C.
8
The groups a –c
refer to steel backing.
Cu backings have to be added,
otherwise they are in class D.
It has to be checked and confirmed that all defect groups
apply unchanged also for Cu
backings?
See separate
explanation
Backing thickness has to be
revised!!
At present consequently all bearings >100 backing are in group
D. That will not be accepted by
the bearing users.
The explanation
of the testing procedure in the
old version of chapter 8 were
confusing. Testing with reference
piece and testing without back
wall contained some mistakes.
Therefore we described it new
and made clear determination:
Chapter 8.1 testing with backwall
Chapter 8.2 testing without
backwall
Testing
The preferred direction of testing is from the bearing metal side under consideration of the back wall echo.
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ISO/WD 4386-1
8.1
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ISO/WD 4386-1
Testing with a back-wall echo
General preconditions are:
a) free access with the transducer to the contact surface
b) back wall is always parallel to the bearing metal surface
c) no hollow spaces within the backing material (drilled holes, channels etc.)
The time base range shall be adjusted so that at least the first back wall echo is visible on the right side of the
screen with an intensity of approx. 80% screen height. The Bond echo is on the left side of the screen near
the input signal. See Figure 1. If in doubt about having the first back wall echo (BE1) on the screen use a reference piece for adjustment.
Bond defect is given when the back wall echo break down and at same time the bond echo on left side of the
screen increase and repeat multiple. See Figure 2. The border of the detected defect area is on the middle of
the transducer diameter when the back wall echo is reduced to its half height under above mentioned conditions. See Figure 3
If the bond and back-wall echo signals become diffuse and missing scanning contact can be excluded this
indicates porosities within the bearing metal. Such areas of porosity shall be regarded as defects due to the
uncertainty of evaluation of the bond.
8.2
Testing without a back-wall echo
If preconditions of chapter 8.1 are not fulfilled testing without back-wall echo becomes necessary.
When porosities around bond defects
have to be included to the defect area (in
the old version), then consequently also
areas of porosities without adjacent bond
have to be declared as defects also.
Therefore the porosity is no longer limited
to defect borders.
Use a reference piece with good bond between similar backing material and similar bearing metal lining as the
tested bearing. Adjust the reference bond echo to 20% of the screen height. See Figure 4 and 5
Bond defect is given when the bond echo is significant above the reference bond height. See Figure 6
If the bond echo signal becomes diffuse and missing scanning contact can be excluded this indicates porosities within the bearing metal. Such areas of porosity shall be regarded as defects due to the uncertainty of
evaluation of the bond.
Same comment as above
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ISO/WD 4386-1
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ISO/WD 4386-1
Table 1 — Defect groups
Bonding
Defect group
Single defect
areaa
Edge zoneb
Defect related to the single edge length
total defect
2
%
but not exceeding
2
mm
%
max.
max.
A
0
0
B1
0,75 b
1
1
5
B2
2b
1
1
5
C
2b
2
2
10
D
4b
5
4
20
Max.
mm
Table of bonding area has to be
renewed
See separate explanation
max.
0
Bush
0
Table of edge
zone has to be deleted. It refers
to penetration testing
See separate explanation
Bearing liner
a)
Plain journal bearings
b)
Plain thrust bearings
Thrustring
a
Table 2 should be located on
chapter 7
Set of thrust pads
The bonding area is the entire continuous actual bonding area of a journal or thrust plain bearing element.
b, in millimetres, represents the functional width of the bearing in the case of journal bearing, and the width of the
segment or ring in the case of thrust bearings.
The summary of single defects may not exceed the maximum total defect.
B
The edge zone is the visible transition from the backing to the bearing metal In the case of journal bearings or thrust
bearings, the edge length is the edge zone of the plane face or the joint face. In the case of pad bearings or tilting pad
bearings, the edge length is the peripheral length of one single pad.
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ISO/WD 4386-1
IS
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ISO/WD 4386-1
Working sketches for the draft.
W
They will be new drawn and proper
marked with IS, BE, WE… later
BE
Figure 1 Testing with a back-wall echo, display of bond
IS
BE
BE
BE
BE
BE
BE
Figure 2Testing with a back-wall echo, display of bond defect
IS
BE
BE
BE
WE
BE
BE
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Figure 3 Testing with a back-wall echo, display of border of bond defect
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ISO/WD 4386-1
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ISO/WD 4386-1
IS
RE
BE BE
Reference piece
Bearing
for
Figure 4 Testing without a back-wall echo, display of reference echo
IS
B
B
Reference piece
Figure 5 Testing without a back-wall echo, display of bond
IS BE BE BE
BE
BE
Reference piece
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Figure 6 Testing without a back-wall echo, display of bond defect
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ISO/WD 4386-1
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ISO/WD 4386-1
Evaluation
When evaluating the test results in accordance with this part of ISO 4386, bond defects equal to or larger than
half the transducer diameter are normally estimated.
Many things can be evaluated by US testing.
This standard is just for bond testing.
..
9.1
Marking of defective areas
If possible, defective areas should be indicated by straight boundary lines. The location of the centre of the
transducer is decisive for determining the transition line between bond and no bond.
The cancelled text is not relevant for bond
testing.
Isolated point-type defects shall be marked with a value equal to half the transducer diameter.
If the distance between two or more defects is less than one-tenth of the bearing width b, then these defects
shall be regarded as one continuous defect.
9.2
Permissible limits of defects
See Table 2.
In the case of journal bearings, it is possible to give a defect classification to different regions of the bearing,
depending on the kind, size and direction of the load (for example, defect group A for the loaded region and
defect group C for other regions).
10 Designation
With reference to this part of ISO 4386, the test class and the defect group shall be indicated as follows.
EXAMPLE
Test Class 2, defect group C shall be designated as:
Test ISO 4386 — 2C
11 Test report
A test report on the result of the test shall be drawn up; however, in the case of test Classes 1 and 2, this shall
be only done by agreement.
The following information shall be included:
a)
reference to this part of ISO 4386;
b)
reference to the tested plain bearing
c)
dimensions, layer thickness and materials of the plain bearing;
d)
test equipment;
e)
type and size of transducer;
f)
test frequency;
g)
amplification and test range;
h)
reference piece (dimensions and materials);
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ISO/WD 4386-1
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ISO/WD 4386-1
i)
testing techniques in accordance with 8.1 or 8.2.
j)
documentation of found defects in a drawing of the sliding surface
k)
test person, date of test;
Above description of procedure
12 Application for quality control
Here some advise for application
for quality control.
The tests should be done by inspectors qualified for ultrasonic testing and with additional experience in bond
testing according to this standard.
In case of any irregularities on bond surface of a bearing backing the relevant area must be collected and
documented in the drawing before lining with bearing metal. This avoids misinterpretation during ultrasonic
testing as a bond defect.
For quality inspection of a bearing the following steps have to be considered:
1. Ultrasonic test based on this standard and evaluation based on Table 2
2. On the edge zones the visible transition from the backing to the bearing metal should be checked
in accordance to Non-destructive penetrant testing ISO 4386-3.
3. Evaluation of defect distribution:
ISO 4386-3 should be revised
with added classification for
edge zones
Detected bond defects on new lined bearings give additional information depending on its location and distribution.
a)
Single bond defects in the flange side edge zone or in the corner between flange side joint side are typical based on local temperature losses during casting procedure. Usually
these defects can be repaired by soldering procedure without any quality reduction.
b)
Single bond defects on sliding surface
If repair work by soldering can be done successful sufficient bond strength is given and no
quality reduction is given.
c)
Many bond defects distributed on sliding surface
Many detected bond defects distributed on the total sliding surface and growing defects during the soldering procedure are indicators for low bond strength at all. Complete renewing of
bearing metal lining is recommended.
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ISO/WD 4386-1
ISO/WD 4386-1
Bibliography
[1]
ISO 6280:1981, Plain bearings — Requirements on backings for thick-walled multilayer bearings
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Plain bearings — Metallic multilayer plain bearings — Part 1: Non-destructive
ultrasonic testing of bond
Schriftart: 10 pt, Nicht Fett, Kursiv, Schriftartfarbe: Blau, Französisch (Frankreich), Rechtschreibung und Grammatik prüfen
Paliers lisses — Paliers lisses métalliques multicouches — Partie 1: Contrôle non destructif aux ultrasons des
défauts d'adhérence
International Standard
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Französisch (Frankreich), Rechtschreibung und Grammatik prüfen
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Englisch (Großbritannien), Rechtschreibung und Grammatik prüfen
Schriftart: 8 pt, Englisch (Großbritannien), Rechtschreibung und Grammatik prüfen