ASTM A213 TP321 Tubes | Solutioning & Stabilizing Heat Treatment

Chemical Composition Requirements

Mechanical Properties

Heat Treatment

The seamless heat exchanger tubes made of ASTM A213 TP321 are mainly used at elevated temperatures with excellent corrosion resistance. Grade TP321 is a stabilized stainless steel, in which titanium is added to avert sensitization to intergranular corrosion. The tubes shall be solutioning heat treated at a temperature between 1900°F [1040°C] and 1950°F [1065°C], followed by a quench in cold water. After all fabrication processes are completed, a stabilizing heat treatment is sometimes required at the temperature of 1650°F [900°C] for 2 to 4 hours. The purpose of the stabilizing heat treatment is to remove carbon from solution at temperatures where titanium carbides are stable but chromium carbides are not. Such treatment prevent the formation of chromium carbide when the steel is exposed to lower temperatures between 800°F [425°C] and 1500°F [815°C]. In this way, ASTM A213 TP321 seamless tubes can be used for applications in long-term exposure at sensitization temperatures.