GB/T 15018-1994 Designation of precision alloys
1 Subject content and applicability
This standard specifies the classification of precision alloys, the expression method and naming rules of alloy designations as well as the general chemical composition of various alloy designations.
This standard is applicable to the classification of all kinds of precision alloys, the expression method, naming and general chemical composition of alloy designations.
2 Classification
2.1 Precision alloys are classified by main physical properties into six categories: soft magnetic alloys, deformable permanent-magnet alloys, elastic alloys, expansion alloys, thermo-bimetals and precision resistance alloys.
3 Terms
3.1
soft magnetic alloys
ferromagnetic or ferrimagnetic alloys with coercivity less than several hundred amps/meter
3.2
deformable permanent-magnet alloy
deformable ferromagnetic or ferrimagnetic alloy with coercivity greater than 104 amps/meter
3.3
elastic alloy
alloy with specific elastic properties
3.4
expansion alloy
alloy with a specific coefficient of linear thermal expansion
3.5
thermo-bimetal
composite material composed of two or more layers of metals or alloys with different linear thermal expansion coefficients
3.6
precision resistance alloy
resistance alloy with small absolute value of resistance temperature coefficient and absolute value of thermoelectromotive force to copper, and good stability
4 Designation expression
4.1 The designation of precision alloys is expressed by combining Arabic numerals with Chinese Pinyin letters.
4.2 The letter "J" (the first letter of "jing" in the Chinese pinyin of "精") and the number before it indicate the category of precision alloy,
namely,
1J——soft magnetic alloy
2J——deformable permanent-magnet alloy
3J——elastic alloy
4J——expansion alloy
5J——thermo-bimetal
6J——precision resistance alloy
4.3 The first and second digits after the letter "J" indicate the serial numbers for different designations of alloys (except thermo-bimetals). The serial number may be numbered from 01 to 99.
In principle, the serial number of alloy designation shall be expressed as the median percentage content of main elements (except iron). If the serial numbers of alloys are duplicated, such number may be expressed by the median of the sum of the percentage content of the main element and the percentage content of the other alloying element, or by the upper (or lower) limit of the percentage content of the main element to show the difference.
4.4 For alloys with the same alloy composition and different properties due to different production processes, or alloys with the same alloy composition (including basically the same alloy composition), different uses and different performance requirements, when it is necessary to distinguish them, they shall be distinguished by Chinese Pinyin letters (the first letter of Chinese Pinyin indicating the main characteristics or uses of the alloy) after the serial number.
1 Subject content and applicability
2 Classification
3 Terms
4 Designation expression
5 Naming of designations
6 Designations and their chemical composition
Annex A Main characteristics and usages of precision alloy products (Reference)
Additional explanation
