This standard is issued under the fixed designation A 430/A 430M; 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 ( ュ) indicates an editorial change since the last revision or reapproval.

1.Scope

1.1 This specification covers heavy-wall, forged and bored austenitic steel pipe (Note 1), intended primarily for high-temperature central station service. Pipe ordered to this specification shall be suitable for bending and other forming operations and for fusion welding. Selection will depend on design, service conditions, mechanical properties and high-temperature characteristics. The "H" grades and nitrogen grades (304N and 316N) are specifically intended for high-temperature service.

NOTE 1ΑThe use of the word "pipe" throughout the several sections of this specification is used in the broad sense and intended to mean pipe, headers, or leads.

1.2 Eleven grades of austenitic steels are covered,. Their compositions are given in Table 1.
1.3 Optional supplementary requirements (S1 through S11) are provided. these sections call for additional tests to be made, and when desired shall be so stated in the order, together with the number of such tests required.
1.4 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 must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the "M" designation of this specification is specified in the order.

NOTE 2ΑThe dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as "nominal diameter," "size," and "nominal size."