Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes ASTM A213 covers seamless ferritic and austenitic steel boiler, superheater, and heat-exchanger tubes.

Grades containing the letter, H, in their designation, have requirements different from those of similar grades not containing the letter, H. These different requirements provide higher creep-rupture strength than normally achievable in similar grades without these

different requirements.

The tubing sizes and thicknesses usually furnished to this specification are 1⁄8 in. [3.2 mm] in inside diameter to 5 in. [127 mm] in outside diameter and 0.015 to 0.500 in. [0.4 to 12.7 mm], inclusive, in minimum wall thickness or, if specified in the order, average wall thickness. Tubing having other diameters may be furnished, provided such tubes comply with all other requirements of this

specification

General use A213/SA213 alloy tubing grades are T5, T9, T11, T12, T22, T91,

Chemical Composition Limits, %, for ASTM A213 Alloy Steel Tubing

For T91 other than above also includes Nickel 0.4, Va 0.18-0.25, Ni 0.06-0.10, Ni 0.03-0.07, Al 0.02, Ti 0.01, Zr 0.01.

A Maximum, unless range or minimum is indicated. Where ellipses (...) appear in this table, there is no requirement, and analysis for the element need not be determined or reported.

B It is permissible to order T2 and T12 with a sulfur content of 0.045 max.

C Alternatively, in lieu of this ratio minimum, the material shall have a minimum hardness of 275 HV in the hardened condition, defined as after austenitizing and cooling to room temperature but prior to tempering. Hardness testing shall be performed at mid-thickness of the product.

Hardness test frequency shall be two samples of product per heat treatment lot and the hardness testing results shall be reported on the material

test rep

Heat Treatment and Grain Size Requirements of A213/SA213