This specification covers the standard requirements for flat-rolled, nonoriented semiprocessed electrical steel intended primarily for commercial power frequency applications in magnetic devices. These electrical steels are low carbon, silicon-iron, or silicon-aluminum-iron alloys, and are classified according to core-loss. Unlike the fully processed electrical steels covered by ASTM A 677, the electrical steels in this specification require heat treatment by the user to develop the specified magnetic properties. The steels covered by this specification have a thickness of either 0.0185 in. (0.47 mm) or 0.025 in. (0.64 mm). For each thickness there are four core loss types. The core loss shall be determined following the use of a quality evaluation anneal listed in the specification. The core loss is determined using the Epstein test method at a test frequency of 60 Hz and a maximum flux density of 15 kG (1.5 T). Test methods to determine other required physical and mechanical properties are listed. Other typical magnetic and physical properties are listed for reference.

1.1 This specification covers the detailed requirements to which flat-rolled, nonoriented semiprocessed electrical steel shall conform.

1.2 This steel is produced to specified maximum core-loss values and is intended primarily for commercial power frequency (50- and 60-Hz) applications in magnetic devices. Desirable core-loss and permeability characteristics are developed through heat treatment by the user.

1.3 These nonoriented, semiprocessed electrical steels are low carbon, silicon-iron or silicon-aluminum-iron alloys containing up to about 2.5 % silicon and less than 1 % aluminum.

1.4 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard.