This specification covers wrought iron-silicon (Fe-Si) relay steels that are generally used in the manufacture of electromechanical devices, such as relays and solenoids, requiring higher electrical resistivity, higher permeability, and lower coercivity and residual magnetism than provided by either carbon steels or soft magnetic low-carbon irons. Available forms and conditions are forging billet, hot-rolled product, cold-finished bars, strip, and wire. These steels are not the same as the flat-rolled non-oriented or grain oriented iron-silicon electrical steels covered by ASTM Specifications A 677, A 683 and A 876. The steels covered in this specification have nominal silicon contents of 1.1, 2.3 and 4.0 % Si. Both the 1.1 and 2.3 % Si types are also available in an enhanced machinability composition. Along with chemical composition, steels produced to this specification must meet a specified maximum value of coercive field strength when heat treated according to this specification. Appendices are given containing typical magnetic, physical and mechanical properties and heat treatment.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
1.1 This specification covers wrought iron-silicon (Fe-Si) steels that are generally used in the manufacture of electromechanical devices, such as relays and solenoids, requiring higher electrical resistivity, higher permeability, and lower coercivity and residual magnetism than provided by either carbon steels or soft magnetic low-carbon irons. The steels covered in this specification are:
|Steel Type||Nominal Composition|
| 1|| 1.1 % Si-Fe|
| 1F|| 1.1 % Si-Fe free machining|
| 2|| 2.3 % Si-Fe|
| 2F|| 2.3 % Si-Fe free machining|
| 3|| 4.0 % Si-Fe|
1.2 This specification covers steels in the form and condition required for fabrication into parts. The fabricated parts typically require a final heat treatment to obtain the desired magnetic performance. The term mill annealed as used in this specification applies to a heat treatment, typically applied by the producer, intended to improve formability. The mill anneal does not provide the optimum magnetic performance and is not intended to replace the need for the finish annealing of parts.
1.3 This specification covers steels in the form of forging billets, hot-rolled bar and strip, cold-finished bar, wire, and cold-rolled strip in thicknesses up to 0.250 in. (6.35 mm).
1.4 This specification does not cover electrical sheet steels used in transformer and motor laminations.
1.5 This specification does not cover powder metallurgy materials capable of being processed into magnetic core components having similar silicon contents.
1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials
A341/A341M Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods
A596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
A773/A773M Test Method for dc Magnetic Properties of Materials Using Ring and Permeameter Procedures with dc Electronic Hysteresigraphs
coercive field strength; iron-silicon steel; relay steel; Alloy steel bars--specifications; Alloy steel forgings--specifications; Annealed steel--specifications; Blanked magnetic core components; Coercive force; Electrical conductors; Electrical relays--specifications; Fe-Si steels--specifications; Forging billets--specifications; Free-machining steel--specifications; Iron-silicon steels--specifications; Lower coercive force; Machined magnetic core components; Magnetic alloys (soft); Magnetic materials/applications--specifications; Mill annealed alloys; Residual magnetism; Permeability--magnetic alloys; Relay steels--specifications; Solenoids;
ICS Number Code 77.140.50 (Flat steel products and semi-products)
ASTM International is a member of CrossRef.
Citing ASTM Standards
[Back to Top]