IS 15420: Metallic Materials - Charpy Pendulum Impact Test - Preparation and Characterization of Charpy V Reference Test Pieces for Verification of Test Machines

16 Pages·2003·1.4 MB·English

by  Bureau of Indian Standards

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IS 15420 (2003): Metallic Materials - Charpy Pendulum
Impact Test - Preparation and Characterization of Charpy V
Reference Test Pieces for Verification of Test Machines
[MTD 3: Mechanical Testing of Metals]
“!ान $ एक न’ भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee””
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”

#’-
IS 15420:2003

Indian Standard
METALLIC MATERIALS — CHARPY PENDULUM
IMPACT TEST — PREPARATION AND
CHARACTERIZATION OF CHARPY V REFERENCE
TEST PIECES FOR VERIFICATION OF TEST
MACHINES
lCS 77.040.10

0 BIS 2003
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
,Vwetnber 2003 Price Group 5
Mechanical Testing of Metals Sectional Committee, MTD 3
F0REWOR13
This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Mechanical
“lesting of Metals Sectional Committee had been approved by the Metallurgical Engineering Division Council.
The suitability of apendulum impact testing machine for acceptance testing ofmetallic materials usually has been
based on a calibration of its scale and verification of compliance with specified dimensions, such as shape and
spacit:g of the anvils supporting the specimen. The scale calibration iscommonly verified by measuring the mass
of the pendulum and its elevation at various scale readings. This procedure for evaluation of machines had the
distinct advantage of requiring only measurements of quantities which can be traced to national standards. The
object ive nature of these traceable measurements minimized the necessity for arbitration regarding the suitability
of the math ines for material acceptance tests.
However. sometimes two machines that had been evaluated by the direct-verification procedures described above
and which met all dimensional requirements, were found togive significantly different impact values when testing
test pieces of the same material specification.
In order to avoid such disagreements, itshall be convenient if, indirectly verified by testing reference test pieces.
A math ine shall be considered acceptable only ifthe values obtained by the machine are within specified limits,
with the reference test pieces.
Inthe preparation of this standard assistance has been derived from the following:
a) 1S0 148-2: 1998(E) Metallic materials —Charpy pendulum impact test— Part 2 : Verification of test
machines
b) 1S0 148-3: 1998(E) Metallic materials —Charpy pendulum impact test—Part 3 Preparation and
characterization of Charpy V reference test pieces for verification of test machines
c) ASTM Designation: E23-93a Standard test methods for notched bar impact testing of metallic materials
The composition of the Committee responsible for formulation of this standard isgiven in Annex B.
For the purpose of deciding whether a particular requirement of this standard is complied with the final value,
observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with

[S2: 1960 ‘Rules for rounding off numerical values (revi.se~’. The number of significant places retained inthe

rounded off value should be the same as that of the specified value inthis standard.
IS 15420:2003
Indian Standard
METALLIC MATERIALS — CHARPY PENDULUM
IMPACT TEST — PREPARATION AND
CHARACTERIZATION OF CHARPY V REFERENCE
TEST PIECES FOR VERIFICATION OF TEST
MACHINES
1SCOPE machine used to determine the reference energy of a
reference test piece. The verification requirements for
1.1 This standard covers the requirements, preparation
this grade of machine are most stringent than those for
and method ofqualifying and certification ofreference
industrial machines.
test pieces that are used to indirectly verify pendulum
impact testing machines. 3.3 Definition Pertaining to Energy
1.2 It describes notched test pieces with nominal 3.3.1 Actual Absorbed Energy (Absorbed Energy),
dimensions identical to those specified in 1S 1757. A, — The total energy required to break a test piece
However, the tolerances are more stringent. The when tested by apendulum impact testing machine. It
chemical composition or heat treatment or both are isequal to the difference in the potential energy from
varied according to the energy level desired. the starting position of the pendulum to the end of the
first half-swing during which the test piece isbroken.
1.3 Reference test pieces are qualified on reference
pendulum impact machines which are also described
3.3.2 IndicatedAbsorbed Energy (Indicated Energy),
inthis standard.
A,— The energy value indicated by the pointer or
2 REFERENCES other readout device of a pendulum impact testing
machine.
The following standards contain provisions which
through reference inthis text, constitute provisions of 3.3.3 Reference Ener~, A~— The absorbed energy
this standard. At the time of publications, the editions associated with reference test pieces, determined from
indicted were valid. All standards are subject to tests made using reference machines. It is the mean
revision, and parties to agreements based on this value of the set tested (see also 6).
standard are encouraged to investigate the possibility
3.4 Lot — A definite quantity of reference test pieces
of applying the most recent editions of the standards

manufactured under identical conditions ofproduction.
indicated below:

[S No. Title 3.5 Reference Test Piece — An impact test piece used
toverify the suitability ofanindustrial pendulum impact
1757:1988 Method for Charpy impact test (V-
testing machine by comparing the indicated energy
notch) for metallic material (second
measured by that machine to the reference energy
revision)
associated with the test piece (see 8).
3766: 1977 Method for calibration ofpendulum
impact testing machines for testing 3.6 Certified Reference Test Piece
metals @-.strevision)
An impact test piece used to verify reference machines
3 DEFIN1TIONS by comparing the impact energy measured by that
machine tothe certified reference value associated with
For the purpose of this standard the following
the test piece.
definitions shall apply.
NOTE —The certified reference value isthevalue determined
3.1 Industrial Machine— Pendulum impact testing by a national or international body following an
machine used for industrial and most research- intercomparison exercise carried out on agroup of reference
machines within itsjurisdiction.
Iaboratory testing of metallic materials. These
lnachines are not used to establish reference values. 3.7 Sets — A group of test pieces chosen at random
[ndastrial machines are verified using direct from a lot.
verification and indirect verification with reference to
3.7.1 Characterization Set — A set oftest pieces taken
test pieces.
from a lot inaccordance with 6and used to determine
3.2 Reference Machine— Pendulum impact testing the reference energy of the lot.
IS 15420:2003
3.7.2 Rc~erence Set—A set of test pieces chosen in Table 1 Symbols and Their Meanings
accordance with 6and 8and used toverify apendulum
(Clause 4)
impact testing machine.
SINo. Symbol Unit Meaning
3.8 Definitions Pertaining to the Test Piece Placed
in the Test Position on the Supports of the Machine (1) (2) (3) (4)
(see Fig. 1and Fig. 2) i) A, J Actual absGrbed energy,
absorbed energy
3.8.1 Height —The distance between the notched face
ii) A, J Indicated absorbed energy,
and [he opposite face. indicated energy
iii) AR J Reference energy of a set of
3.8.2 lVic/~h—The dimension perpendicular to the
Cbarpy reference test pieces
height and parallel to the notch.
used todetermine the reference energy ofreference test
3.8.3 Leng[}l—The largest dimension at right angles
[0the notch. pieces shall be as specified in Table 2 and Fig. 1and
Fig. 2. Other characteristics shall however, comply
-1SYMBOLS with the requirements of IS 3766.
‘Hlesymbols used in this standard are as indicated in 5.1.1 The radius at the base of the notch shall be
‘l-abl1e. tangential to the notch angle.
5 REFERENCE TEST MACHINE
5.1.1.1 The surface finish shall not exceed 1.6 pm on
5.1 Characteristics the notched surface or 3.2 pm of the other surface.
The geometrical characteristics of reference machines 5.1.1.2 Identification marks shall not be placed inany
Table 2 Geometrical Characteristics (see Fig. 1and Fig. 2)
(Clause 5.1)
SiNo. Number in Fig. 1 Designation Size Tolerance Units
(1) (2) (3) (4) (5) (6)
1) Length oftest piece 55.00 +0 mm
– 0.30
ii) 2 Half-length oftest piece 27.5 i 0.20 mm
iii) 3 Height oftest piece 10.00 * 0.06 mm
it) 4 Width oftest piece 10.00 +0.075 mm

v) 5 Ligament le n gth 8.00 * 0.06 mm
vi) 6 Angle of notch 45 +1 deg
vii) 7 Radius ofcurvature ofbase ofnotch 0.250 +0.025 mm
viii) 8 Angle between adjacent faces 90 +0.15 deg
i\) 9 Angle between plane ofsymmetry of 90 *2 deg
notch and longitudinal axis
~) 10 Radius of anvils 1 +0.1 mm
-o
Ri) II Angle of taper ofanvils 11 deg
\ii) 12 Distance between anvils 40.0 +0,1 mm
-o
\ii) 13 Distmce ofstriking edge from plane mm
ofsymmetry of anvils
\i\) 14 Angle of striker 30 *I deg
\\) 15A Radius of curvature ofstriking 2t02.5 mm
of2 mm striker
\vi) Radius of curvature ofstriking edge of 8.0 * 0.05 mm
8mm striker
\\’ii) I5C Radius ofshoulder of 8mm striker 0.2 toI,0 mm
\\iii) 15D Width ofstriking edge of 8mm striker 4.0 * 0.05 mm
2
Types of striker
.~-./
‘,TI—- I
;
..
\,,
r-.–15B
‘...
I
L
2mmstriker I
V
-!
~
-L,
u
x
8 mm~triker
13
+-
I
line of strike -—
9
h

2 7
.—_—____ -.
8
I
.[
////////////,
/
/
10
10
6 /
~
N
I
12

Fi~. 1 DIMENSIONS OFTEST PIECES, ANVILS ANDSTRIKERS
3
IS 15420:2003
\
.nvi~ ;
Height of ~
!es! ~lece
/
Width of
.---’
test piece
\
\
Test piece
L Recess
supports

FJ~. 2 CONIOGURATIONOFTwr PIECE SUPPORTS ANDANVILS INAREFERENCE
PEN~ULUM IMPACTTESTING MACHINE
area ofthe test piece that contacts the striker edge, anvils equipment inclose proximity, such asforging hammers,
or test piece supports, or within 5 mm of the notch. presses, moving vehicles.
5.I.2 Capacity NOTE — Such vibrations can bedetected by placing asmall
container ofwater atany convenient location on the machine
The capacity of a reference machine shall be 300 Jor framework, theabsence ofripples onthewater surface indicates
greater. that this requirement ismet. Excessive vibration inamachine
firmly fastened to the floor indicates the need for aseparate
5.1.3 Hardness foundation and/or the use of vibration isolators.
5.1,5 Ener~ Indicating Mechanism
The portions of the striker and the anvils (see Fig. 1)
which contact the specimen and apply or react to the The resolution shall beat least l/400th of the nominal
impacting force shall have a minimum hardness of energy.
56 I{RC.
5.2 Qualification of Reference Test Machine
5.1.4 Vibration
Direct verification shall be carried out in accordance
Ensure that the reference machine is not subjected to with IS 3766 and with the additional requirements
external (random) vibrations induced by other Ofs.1.

4
IS 15420:2003
5.2.1 Indirect verification shall be carried out using machine annually for a complete inspection. If
certified reference test pieces. The repeatability and the any parts are found to be damaged, they shall be
error shall be as specified inTable 3. replaced and the machine shall be re-qualified (see 5.1
and 5.2).
Table 3 Repeatability and Error of Reference
Pendulum Impact Machines 5.3.3.1 During the annual inspection of the reference
machine, the flatness of the anvils surfaces (which
(Clause 5.2.1)
absorb the force transmitted through the test piece) and
(All Valercs inJoules)
the adjacent radii shall be examined for local wear
S1No. Energy, /3 Repeatability Error or damage or both. The results of this examination
(1) (2) (3) (4) shall be retained until the anvils are replaced or
re-machined.
O <40 <3 <2
ii) >40 S7.5 %ofAR 5 5% ofAR The radius (radii) ofthe striking edge of the striker and
the radii of the anvils surfaces which are contacted by
NOTE — Repeatability isgiven by: Av~,y–A,,~,n;and Error
the test piece shall be measured and documented inthe
isgiven by :A, –AR,
same manner.
where
Ifitbecomes necessary to repair the recording system,
Av1+Av2+ Av3+....+Avn
itshall be recalibrated before additional tests are made
~v=—
n (see 5.2).
NOTE — This examination can be done, for example, by
5.3 Use of Reference Test Machine making impressions ofthesurfaces insilicone rubber oranother
low-shrinkage material, orby holographic methods.
The procedure for the operation of the reference
5.4Calibration ofInspection, Measurement and Test
machine shall conform to the requirements of IS 1757
Equipment
and 1S 3766 and to the following additional
requirements. All equipment used bythe supplier for final inspection
and testing shall be calibrated and shall have a
5.3.1 The angular position of the pendulum at the
certified traceability tothe S1system (the international
extremes of its swing or the impact energy calculated
system ofunits). The supplier shall maintain calibration
there from shall be automatically recorded indigital or
records for all inspection, measurement and test
graphical form. These records shall be in permanent
equipment.
form suitable for evaluation at any time until one year
after the entire batch of reference test pieces has been 5.5 Log Book
distributed.
The dates and details of all inspection and repairs shall

5.3.2 The combined windage and fr iction loss during be documented in a log book maintained for each

11successive half swings shall bemeasured before and reference machine.
after testing each characterization set and the values
6 REFERENCE TEST PIECES
recorded.
6.1 Material
5.3.2.1 To ensure that total friction and windage losses
are within the permissible limit following steps of
6.1.1 All the test pieces from a lot shall come from a
checking may be employed:
single ingot or melt.
a) Secure the pendulum in its maximum energy
6.1.2 All test pieces shall be made of steel. The
position and release itwithout aspecimen inthe
composition of the test pieces is not specified. Lots
machine, the energy reading should show
with different energy levels may have different
OJoule.
compositions.
b) Again release the pendulum from itsmaximum
6.1.3 All test pieces from a lot shall receive the same
energy position without re-settirrg the stage
heat treatment.
pointer and allow it to swing 1lth half cycles;
and as the pendulum starts its 1Ith half cycle, 6.1.4 For each lot, the referenc~ energy shall fall
shift the slave pointer to between 5 to 10 within one of the following ranges:
percent of scale range capacity and note the
energy value. The value obtained divided by LOW : <30J
11should not exceed 0.4 percent of scale range Medium : >30Jto<l10J
capacity. High : >110Jto<220J
5.3.3 Theanvils and striker shall be removed from the Ultra High : 2220 J
5