ASTM A269 TP321 SMLS Tubing | Coiled & Off The Shelf

ASTM A269 Gr. TP321 is a stabilized austenitic stainless steel. Titanium is added to form more stable titanium carbides prior to the formation of chromium carbides. Thus, depletion of chromium at sensitization temperatures will not occur, resulting in improved resistance to intergranular corrosion. The ASTM A269 TP321 tubing is especially suitable for applications which involve long-term exposure to temperatures 800-1500°F [425-815°C].

Chemical Composition Requirements

Hardness Requirements

Heat Treatment

ASTM A269 TP321 tubing shall be solution annealed at a temperature between 1900°F [1040°C] to 1950°F [1065°F], followed by a quench in water. Upon buyer’s request, stress-relieving heat treatment or stabilizing heat treatment can be provided. Stress relieving heat treatment shall be performed at 1550 to 1650°F [845 to 900°C] after roll straightening. Cooling from this temperature range may be either in air or by slow cooling. When required, stabilizing heat treatment shall be performed subsequent to the solution annealing after fabrication is completed. Usually, the stabilization temperature shall be around 1650°F [900°C].

Permissible Variations (Tolerances) in Dimensions

Intergranular Corrosion Test

When required, ASTM A269 TP321 tubes shall pass intergranular corrosion tests conducted in accordance with Practice E of ASTM A262: copper-copper sulfate-sulfuric acid test for detecting susceptibility to intergranular attack in austenitic stainless steels.