ASTM E1236-91(1997)

Standard Practice for Qualifying Charpy Impact Machines as Reference Machines (Withdrawn 2006)

SCOPE
1.1 This practice lists the physical requirements that an impact machine shall meet in order to be registered as a reference machine.
1.2 This practice describes the procedure by which a reference machine shall be qualified to make tests to establish reference values.
1.3 These requirements and procedures are not intended to be applied to impact machines and testing procedures used for purposes other than to qualify machines for the determination of reference values of verification specimens.
1.4 This practice does not describe the procedure by which the reference value for a specified reference material is determined. The procedure varies with the material being tested and is to be found in different standards for various specified verification materials.
1.5 Values stated in inch-pound units are to be regarded as the standard. SI units are given for information only.
1.6 This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This practice lists the physical requirements that an impact machine shall meet in order to be registered as a reference machine.
Formerly under the jurisdiction of Committee E28 on Mechanical Testing, this practice was withdrawn in February 2006 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 09-Dec-1997
• Withdrawal Date: 12-Feb-2006
• ICS: 19.060 - Mechanical testing
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.07 - Impact Testing

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E1236–91(Reapproved 1997)
Standard Practice for
Qualifying Charpy Impact Machines as Reference Machines
This standard is issued under the fixed designation E 1236; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Some standards for impact testing require that the bias of the machines be evaluated by testing one
or more sets of specimens with known impact energy. These specimens are called verification
specimens. The known value is determined by tests using three machines which, by consensus, are
designated as giving correct results. Such machines will be referred to as reference machines and the
impact energy values determined from tests using these machines will be referred to as reference
values.
In order to assure an adequate supply of verification specimens and also to assure that the reference
values are not influenced by uncontrolled changes in one reference machine, it is necessary to
recognizeseveralmachinesasreferencemachines.However,whenseveraldifferentmachinesareused
to test a large number of specimens from the same lot, the average impact energy from each machine
isusuallydifferentfromthecorrespondingvaluesfromtestsbyothermachines.Thispracticeprovides
procedures for minimizing these differences.
1. Scope 2. Referenced Documents
1.1 This practice lists the physical requirements that an 2.1 ASTM Standards:
impact machine shall meet in order to be registered as a E 23 Test Methods for Notched Bar Impact Testing of
reference machine. Metallic Materials
1.2 This practice describes the procedure by which a refer- E 178 Practice for Dealing with Outlying Observations
ence machine shall be qualified to make tests to establish E 456 Terminology Relating to Quality and Statistics
reference values. E 691 Practice for Conducting an Interlaboratory Study to
1.3 These requirements and procedures are not intended to Determine the Precision of a Test Method
be applied to impact machines and testing procedures used for
3. Terminology
purposes other than to qualify machines for the determination
of reference values of verification specimens. 3.1 Definitions of Terms Specific to This Standard:
3.1.1 coordinator—the person or agency who conducts the
1.4 This practice does not describe the procedure by which
the reference value for a specified reference material is annual interlaboratory coordination program and maintains a
file on all reference machines.
determined. The procedure varies with the material being
tested and is to be found in different standards for various 3.1.2 impact energy—the energy required to break a speci-
men when tested by an impact machine. It is equal to the
specified verification materials.
difference in the potential energy of the pendulum at the start
1.5 Values stated in inch-pound units are to be regarded as
the standard. SI units are given for information only. and at the end of a swing during which a specimen is broken,
minus the proportional amount of windage and friction loss
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the which corresponds to the angle of swing.
3.1.3 lot—a definite quantity of some commodity manufac-
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- tured under similar conditions of production.
3.1.3.1 Discussion—With the exceptions noted, the defini-
bility of regulatory limitations prior to use.
tions of statistical terms given in Terminology E 456 shall
apply.
This practice is under the jurisdiction ofASTM Committee E28 on Mechanical
Testing and is the direct responsibility of Subcommittee E28.07 on Impact Testing.
Current edition approved Jan. 25, 1991. Published March 1991. Originally Annual Book of ASTM Standards, Vol 03.01.
published as E 1236 – 88. Last previous edition E 1236 – 88. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1236–91 (1997)
3.1.4 reference machines—impact machines meeting the These records shall be in permanent form suitable for evalua-
requirements of this practice. tion at any time until 1 year after all the specimens from the
3.1.5 reference value—the impact energy value furnished same lot have been tested or sold.
with verification specimens, determined from tests made using
6.1.2.4 If impact energy is automatically calculated and
reference machines.
printed,thevalueshownshallberoundedto0.1ft·lbf(0.1J)or,
3.1.6 set—a group of specimens chosen at random from a
optionally, 0.5 % of the impact energy, if greater.
lot, to be later tested successively in a single machine.
6.1.2.5 If pendulum position is recorded, the record shall be
3.1.6.1 Discussion—With the exceptions noted, the defini-
readable to an angle corresponding to the larger of 0.2 ft·lbf
tions of statistical terms given in Terminology E 456 shall
(0.3 J) or 1 % of the impact energy.
apply.
6.2 Environment of the reference machine shall be similar
3.1.7 specified verification material—any one of several
to that of the average quality control environment with specific
materials that meet a specification given in a standard that
attention to the following factors:
describes verification specimens.
6.2.1 The machine shall be in an enclosed area with
3.1.8 verification specimens—impact specimens to be used
sufficient lighting and clearance around the equipment to
to evaluate the suitability of a machine for material acceptance
permit convenient access for conducting the necessary periodic
testing by comparing the impact energy measured by that
inspections and maintenance.
machine to the reference value furnished with the specimens.
6.2.2 Normal room temperature and humidity is satisfac-
tory. No concentrated heating or cooling sources shall be
4. Summary of Practice
located near or directed toward the machine or its indicating
4.1 Any impact machine that meets the physical require-
mechanism.
ments of this practice may be a candidate reference machine.
6.2.3 The atmosphere shall be sufficiently clean to prevent
Before the machine is permitted to be used to determine
the accumulation of dust or foreign material that could con-
reference values, it shall be qualified by participating in an
taminate the bearings or otherwise cause damage to the
interlaboratory coordination program that compares results
equipment which would affect its performance.
from all candidate reference machines at low, medium, and
6.2.4 The reference machine shall not be subjected to
high energy levels.The average value and variability of the test
external (random) vibrations induced by other equipment in
results from each machine are compared to corresponding
close proximity, such as forging hammers, presses, vehicular
values from all machines combined. If the differences between
movements, and so forth.Vibrations discernable by placing the
the value from a particular machine and the combined value is
hand on the pendulum would be considered excessive.
less than the amounts specified in this practice, that machine is
certified as a reference machine for the next twelve months or
NOTE 1—Excessive vibration from a machine firmly fastened to the
until the next report of the interlaboratory coordination pro- floor indicates the need of a separate foundation or base connected to the
floor by vibration isolators.
gram is distributed.
7. Selection of the Coordinator of the Interlaboratory
5. Significance and Use
Coordination Program
5.1 This practice is expected to increase the availability of
7.1 The machine owner accepting responsibility for the
verification specimens by permitting an increase in the number
coordinative function has the option of assigning an employee
of qualified reference machines.
or of contracting with a person or agency outside the owner’s
organization to serve as coordinator.
6. Apparatus
7.2 Timing—The coordinator of the next program shall be
6.1 Reference Machines, used to determine the reference
designated within 60 days of the distribution of the report of
values for a specified verification material, shall comply with
the preceding program.
the requirements of the standard for verification specimens of
7.3 For the first year of the program, the coordinative
that material.
responsibility will be assigned to the owner of reference
6.1.1 Unless specifically stated otherwise in the standard for
machine A.
verification specimens, reference machines shall comply with
7.4 For the second and subsequent programs, the machine
the requirements of Test Method E 23, except as modified in
owner who last accepted responsibility will request succes-
6.1.2.
sively, in alphabetical order, the other owners to designate the
6.1.2 The requirements for reference machines shall differ
coordinator for the next program.
from those given in Test Method E 23, as follows:
6.1.2.1 The capacity of a reference machine shall be 240 7.4.1 If none of the owners voluntarily accept the coordina-
ft·lbf (330 J) or greater. tive responsibility, the responsibility shall be assigned to the
6.1.2.2 The portions of the striker and anvils that contact the owner whose machine has the first alphabetical identification
specimen and apply or react to the impacting force shall have letter among those who have previously accepted the respon-
a hardness of 56HRC or greater. sibilitytheleastnumberoftimesperreferencemachineowned.
6.1.2.3 The angular position of the pendulum at the ex- If that owner refuses to accept the assignment, that machine
tremes of the swing or the impact energy calculated therefrom shall be excluded from the next program and thereby loses
shall be automatically recorded in digital or graphical form. reference machine status.
E1236–91 (1997)
8. Calibration and Standardization (d) The request shall require that the quotation include the
results of tests on specimens randomly selected from the lot
8.1 Calibration and verification of reference machines shall
being offered. These results shall include average impact
conform to Test Methods E 23.
energy,thestandarddeviation,thetesttemperature,thenumber
8.2 Registration of Reference Machines:
of specimens tested, and all other information needed to show
8.2.1 Registration shall be initiated by a letter of application
that the offered lot meets the specifications of the standard for
from the machine owner to the coordinator. The letter shall
verification specimens of that material.
furnishtheinformationandmakethecommitmentsthatfollow:
(e) The request shall state that the minimum number of
8.2.1.1 Identify the machine and certify that the require-
specimens required to be in each lot shall be equal to the
ments of Section 6 are satisfied.
product of 1.5 times the number of registered reference
8.2.1.2 State that the owner agrees to participate in the machines and the number of specimens in each set. Unless
annual interlaboratory coordination program. otherwise required by the standard for the verification speci-
mens, each set shall consist of 25 specimens. The inquiry shall
8.2.1.3 State that the owner will permit suppliers and users
state that the quoted lot size shall be reserved for use in the
of the verification specimens tested by this machine to see the
interlaboratory coordination program for at least twelve
machine and examine the permanent records required by this
months after the first specimens are delivered.
practice. These inspections are to be by appointment at the
owner’s convenience. (f) The request shall require that the specimen be perma-
nently marked with coded letters to identify the lot from which
8.2.2 The coordinator will assign the next letter of the
it was drawn and also with a number to uniquely identify that
alphabet to that machine for identification.
specimen from all others within the lot and that the specimens
8.2.3 The coordinator will acknowledge the receipt of the
for each set shall be drawn at random from the lot. The
application by a letter addressed to the owner. An attachment
specimen numbers for each set shall be retained in a permanent
will list all currently registered reference machines by identi-
record.
fying letter and give the name, address, and telephone number
(g) The request shall state that only quotations submitted
of the owner of each machine.
before the end of February will be considered.
8.3 Theinterlaboratorycoordinationprogramwillconsistof
8.3.3.2 The coordinator shall then send copies of all quota-
specimen procurement and testing, and the comparison of test
tions for specimens to participating machine owners. Each
results to determine whether the deviation and variability of
owner shall be requested to vote during April for a specimen
each machine is within the limits specified in 8.3.6 and 8.3.7.
supplier at each energy level. Each owner shall have one vote
8.3.1 The specimen shall meet the dimensional require-
for each of the owner’s machines that is to be qualified.
ments given in Test Methods E 23 for Charpy Impact
8.3.3.3 DuringMay,thecoordinatorshallnotifythesupplier
Specimens-Type A, and any additional requirements imposed
whose proposal received the most votes at an energy level to
by the standard for verification specimens.
expect orders for specimens at that level. The coordinator shall
8.3.2 If all of the candidate machines are under the control
notify all others who quoted that their proposal did not receive
of one person or organization, that owner shall be responsible
themostvotes.Inthecaseofatie,thecoordinatorshallcastthe
for conducting the interlaboratory coordination program and
deciding vote.
for keeping a summary report on file.
8.3.3.4 During May, the coordinator shall send a letter to
8.3.3 If the candidate reference machines are under the
each voter stating that a set of specimens for each candidate
control of two or more owners, the coordinator shall conduct
reference machine at each level shall be obtained by sending a
the interlaboratory coordination program as described in
purchase order to the chosen supplier(s). The letter shall also
8.3.3.1-8.3.8.2.
give a schedule for reporting the results of the tests and a blank
8.3.3.1 During January of each year, the coordinator shall
form for recording the data and all other information required
request quotations of price and delivery for the specimens
for the summary report.
needed for the interlaboratory coordination programs.
8.3.4 Each owner shall test a set of specimens at
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