ASTM A991/A991M-98(2004)
(Test Method)Standard Test Method for Conducting Temperature Uniformity Surveys of Furnaces Used to Heat Treat Steel Products
Standard Test Method for Conducting Temperature Uniformity Surveys of Furnaces Used to Heat Treat Steel Products
SIGNIFICANCE AND USE
Furnaces for heat treatment of steel products are used in many industries, in many ways. Regardless of heat treat furnace type, or processing cycle, it may be necessary for users to know the temperature uniformity in the furnace and whether the material is processed in a zone within the furnace that is capable of meeting the applicable permissible temperature variation requirements.
The procedures in this test method may be used by those using, manufacturing, and providing calibration service for, heat treat furnaces used to process steel products.
SCOPE
1.1 This test method covers the procedures used to conduct a temperature uniformity survey on a furnace used to heat treat steel products. This method is used to determine the capability of the furnace to meet the permissible temperature variation specified in the applicable product specification, or as agreed to by the purchaser and supplier of heat treat services. Survey documentation requirements, and the procedure used to subsequently establish the furnace working zone, are defined in this test method.
1.2 This test method covers heat treat furnaces in any of the following categories:
1.2.1 Continuous or semi-continuous conveyance furnaces,
1.2.2 Batch furnaces, and
1.2.3 Salt or liquid baths and fluidized beds.
1.3 This test method only applies when specified in the product specification or the purchase order.
1.4 Controlling a heat treatment of steel products using thermocouples attached to the extremities of each load is an alternative to performing a furnace survey.
1.5 By mutual agreement between the purchaser and the supplier of heat treat services, more stringent and/or additional requirements may be specified. The acceptance of any such additional requirements shall be dependent on negotiations with the supplier and must be included in the order as agreed upon by the purchaser and supplier.
1.6 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system is to be used independently of the other, without combining values in any way.
1.7 This standard does not purport to address all of the safety concerns, if any, 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.
General Information
Relations
Standards Content (Sample)
Designation:A991/A991M–98(Reapproved 2004)
Standard Test Method for
Conducting Temperature Uniformity Surveys of Furnaces
Used to Heat Treat Steel Products
This standard is issued under the fixed designationA 991/A 991M; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method covers the procedures used to conduct 2.1 ASTM Standards:
a temperature uniformity survey on a furnace used to heat treat E 207 Test Method for Thermal EMF Test of Single Ther-
steel products. This method is used to determine the capability moelement Materials by Comparison with a Reference
of the furnace to meet the permissible temperature variation Thermoelement of Similar EMF-Temperature Properties
specified in the applicable product specification, or as agreed to E 220 Test Method for Calibration of Thermocouples By
by the purchaser and supplier of heat treat services. Survey Comparison Techniques
documentation requirements, and the procedure used to subse- E 230 Specification and Temperature-Electromotive Force
quently establish the furnace working zone, are defined in this (EMF) Tables for Standardized Thermocouples
test method. E 608/E 608M Specification for Mineral-Insulated, Metal-
1.2 This test method covers heat treat furnaces in any of the Sheathed Base Metal Thermocouples
following categories: 2.2 SAE Standard:
1.2.1 Continuous or semi-continuous conveyance furnaces, AMS 2750 Pyrometry
1.2.2 Batch furnaces, and
3. Terminology
1.2.3 Salt or liquid baths and fluidized beds.
1.3 This test method only applies when specified in the 3.1 Definitions of Terms Specific to This Standard:
3.1.1 batch furnace, n—heating device in which material
product specification or the purchase order.
1.4 Controlling a heat treatment of steel products using may be stationary or oscillating during the processing cycle.
3.1.2 continuous conveyance furnace, n—heating device
thermocouples attached to the extremities of each load is an
alternative to performing a furnace survey. through which material is moved intentionally at a constant
rate during the processing cycle.
1.5 By mutual agreement between the purchaser and the
3.1.3 extremities, n—as referring to furnace working zone;
supplier of heat treat services, more stringent and/or additional
requirements may be specified. The acceptance of any such outer boundaries in all three dimensions (length, width, and
height) of the material being processed.
additional requirements shall be dependent on negotiations
with the supplier and must be included in the order as agreed 3.1.4 operating range, n—expected range of temperature
over which a furnace will be controlled to heat treat steel
upon by the purchaser and supplier.
1.6 The values stated in either inch-pound units or SI units products.
3.1.5 primary survey, n—initial evaluation of the furnace,
are to be regarded separately as standard. Within the text, the
SI units are shown in brackets. The values stated in each or an evaluation triggered by the initiation of a major furnace
modification.
system are not exact equivalents; therefore, each system is to
be used independently of the other, without combining values 3.1.6 secondary survey, n—evaluation of the furnace trig-
gered by the expiration of a time requirement.
in any way.
1.7 This standard does not purport to address all of the 3.1.7 semi-continuous conveyance furnace, n—heating de-
vice through which material is moved intentionally with a
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- predetermined start-stop-start pattern during the processing
cycle.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1 2
This test method is under the jurisdiction of ASTM Committee A01 on Steel, For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
A01.13 on Mechanical and Chemical Testing and Processing Methods of Steel Standards volume information, refer to the standard’s Document Summary page on
Products and Processes. the ASTM website.
Current edition approved Oct. 1, 2004. Published October 2004. Originally Available from Society of Automotive Engineers (SAE), 400 Commonwealth
approved in 1998. Last previous edition approved in 1998 as A 991/A 991M – 98. Dr., Warrendale, PA 15096-0001.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A991/A991M–98 (2004)
3.1.8 working zone, n—maximum volume and location in 6.1.3 The furnace atmosphere and operating conditions
the furnace that meet the permissible temperature variation. shall be representative of those used in production.
6.2 Frequency of Uniformity Surveys:
4. Significance and Use
6.2.1 Primary Surveys:
4.1 Furnaces for heat treatment of steel products are used in 6.2.1.1 A primary survey shall have been performed within
many industries, in many ways. Regardless of heat treat
twelve months prior to, or run concurrently with, the first
furnace type, or processing cycle, it may be necessary for users production heat treatment to which this test method applies.
to know the temperature uniformity in the furnace and whether
6.2.1.2 Aprimary survey shall have been conducted when a
the material is processed in a zone within the furnace that is major furnace modification is completed. A major furnace
capable of meeting the applicable permissible temperature
modification includes, but is not limited to, the installation of
variation requirements. the following: a different burner type, a new heating element
4.2 The procedures in this test method may be used by those
design, a different type of insulation system, and, a different
using, manufacturing, and providing calibration service for, type of temperature controlling device.
heat treat furnaces used to process steel products.
6.2.1.3 Replacement of worn parts with similar parts or
patching of insulation that does not change the furnace
5. Furnace Survey Equipment
characteristics does not constitute a major furnace modifica-
5.1 Thermocouples:
tion.
5.1.1 Metal sheathed thermocouples shall be in accordance
6.2.1.4 The survey shall be conducted within twelve months
with Specification E 608/E 608M.
prior to, or run concurrently with, the first production heat
5.1.2 The use of extension wires is permitted when com-
treatment performed after the modification.
pensated connectors, plugs, jacks, and terminal strips are used.
6.2.2 Secondary Surveys:
5.1.3 Thermocouples made from spool wire shall meet the
6.2.2.1 To maintain conformance with this test method, a
requirements of AMS 2750.
secondary survey shall be conducted within twelve months
5.1.4 The use of spliced extension wire is prohibited.
after the primary survey.
5.1.5 Thermocouples may be reused if the requirements of
6.2.2.2 Secondary surveys shall be conducted at a typical
AMS 2750 (except Paragraph 3.1.1.7.2 of Rev. C) are met.
furnace set point temperature within the normal operating
5.2 Calibration:
range. All other conditions described in 6.1 shall apply.
5.2.1 All reference, primary, secondary, test and working
7. Procedure
equipment, instrumentation and sensors used in conjunction
7.1 Survey measuring equipment shall meet the require-
with this test method shall meet the requirements of calibration
defined by Test Methods E 207 and E 220. ments of Section 5.
7.2 Test conditions and test frequency shall be as defined in
5.2.2 Temperature measuring devices shall be calibrated
within three months prior to use. 6.1 and 6.2, respectively.
7.3 Place thermocouples to monitor time and temperature
5.2.3 Calibration shall be traceable to the National Institute
of Standards Technology standards, or equivalent national profiles in the furnace to evaluate the uniformity of the
intended working zone. Place them at the outer extremities, the
standards. Calibration to such national standards shall be done
at least once every two years. center of the proposed working zone, and in areas of suspected
variability in the proposed working zone. Attach survey test
5.2.4 Calibration shall be within the temper
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.