GB/T 4339-1999 Determination of characteristic parameters of thermal expansion of metallic materials

This standard specifies the definition and symbols, principles, test equipment and requirements, sample preparation, dilatometer calibration, measurement procedures, measurement result calculation, test report, accuracy and deviation of the expansion characteristic parameters of metal materials and other related solid materials. GB/T 4339-1999 Determination of thermal expansion characteristic parameters of metallic materials GB/T4339-1999 standard download decompression password: www.bzxz.net

GB/T 4339-1999
This standard adopts the American Society for Testing and Materials ASTME228-1995 "Standard Method for Testing Linear Thermal Expansion of Solid Materials with Transparent Quartz Dilatometer" and revises GB/T43391984 "Method for Measuring Thermal Expansion Characteristic Parameters of Metallic Materials". It is basically the same as ASTME228-1995 in terms of scope, definition and symbols, test equipment, technical requirements, operating points, numerical calculation and accuracy analysis methods. It is different from ASTME228-1995 in terms of reference standards, sample size, selection and use of displacement and temperature sensors. Considering that TMA dilatometer has become one of the main types of commercial instruments, this standard adds the use regulations of TMA instrument in ASTME831-1993 "Standard Method for Testing Linear Thermal Expansion of Solid Materials with Thermomechanical Analyzer". Since the accuracy of modern displacement sensors can reach a very high level, this standard does not limit the detection range of expansion coefficient and the scope of application of TMA method. This revision of the standard has been modified in the following aspects: adding principles, reference standards, symbol definitions, material requirements and annealing process and cleaning of quartz components, shape and size requirements of push rods and limits on the force applied to push rods, standard push specimen data table, use of TMA instrument in expansion test and accuracy and deviation and other chapters and contents;
- Expanded the temperature application range, specimen preparation, test device calibration and other contents; - Simplified and organized the section "Measurement steps and temperature change program", focusing on the provisions related to automatic measurement, and clearly stipulated that baseline correction must be performed when using TMA instrument to complete the expansion material detection; especially when detecting low expansion materials, at least three specimens should be tested for one material;
- Modified the outdated parts such as "Dilator structure diagram", "Extensometer", "Error", etc., and was stricter than before in terms of instrument selection and calibration, accuracy calculation, etc. This standard replaces GB/T4339-1984 "Method for measuring thermal expansion characteristic parameters of metallic materials" from the date of implementation. Appendix A of this standard is the appendix of the standard.
This standard is proposed by the State Metallurgical Industry Bureau.
This standard is under the jurisdiction of the Metallurgical Information Standards Institute. The drafting units of this standard are: Metallurgical Research Institute of Shougang Corporation and Guangzhou Nonferrous Metals Research Institute. The main drafters of this standard are: Wang Liyun, Li Shuwen and Li Xin. This standard was first issued in April 1984.
1 Scope
National Standard of the People's Republic of China
Testing method for thermal expansioncharacteristic parameters of metallic materialsGB/T 4339—1999
Replaces GB/T4339—1984
This standard specifies the definition and symbols, principles, test equipment and requirements, sample preparation, dilatometer calibration, measurement procedures, calculation of measurement results, test reports, accuracy and deviation of the thermal expansion characteristic parameters of metallic materials and other related solid materials. This standard is applicable to the detection of linear thermal expansion of metal material samples in a temperature range of 180-900℃ with the aid of an assembly consisting of the same type of fused quartz carrier and push rod. It is also applicable to the detection of linear thermal expansion of samples with rigid solid characteristics such as ceramics, refractory materials, glass, and rocks. If a high-purity alumina assembly is used instead, the temperature range can be extended to 1600℃; if isotropic graphite is used instead, it can be extended to 2500℃. www.bzxz.net
2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T8170—1987 Rules for rounding off values
GB/T10562--1989 Method for measuring ultra-low expansion coefficient of metallic materials - optical interference method JJG141-1988 Verification procedure for industrial Pt10 (Pt13)-Pt thermocouples JJG229—1987 Verification procedure for industrial nickel-chromium-nickel-silicon and nickel-chromium-copper thermocouples JJG351—1984 Verification procedure for industrial platinum-copper thermal resistors 3 Definitions and symbols
3.1 Linear thermal expansion
The change in length per unit length of the specimen corresponding to the change in temperature is expressed as △L/L.; where △L is the measured change in length and L. is the length of the specimen at the reference temperature t. Thermal expansion is usually expressed as a percentage or parts per million (10-6). Generally, 20°C is used as the reference temperature.
3.2 Average linear expansion coefficient
The average value of the relative change in the length of the specimen corresponding to a temperature change of 1°C between temperatures t and t, expressed as αm: am (Lz -- LI)/[L(t2 - t)] = (AL/Lo)/At(t
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