ASTM A213 TP321 Stainless Steel Seamless Tube Corrosion Resistance Low Temperature

Stainless steel is commonly known as corrosion-resistant steel, as it offers better resistance to staining, corrosion, and rust compared to regular carbon steel. However, it is important to note that stainless steel is not completely immune to corrosion. Its resistance to corrosion is primarily due to the presence of chromium, which forms a protective layer on the surface, preventing surface corrosion. In contrast, carbon steel tends to rust when exposed to moisture and air. Stainless steel's antioxidant properties make it a popular choice in various applications.

Stainless steel sheets are a preferred option when low maintenance and corrosion resistance are required. They find application in diverse areas, ranging from cladding or fascia in modern buildings to the food hygiene industry, thanks to their antimicrobial qualities.

Stainless Steel Seamless (SMLS) pipes are manufactured by drawing a solid billet over a perforated rod, creating a hollow shell. The absence of welding in the manufacturing process makes seamless pipes stronger and more reliable. Historically, seamless pipes have been considered more resistant to pressure than other types, and they are generally more readily available than welded pipes.

Grades 321 and 347 are basic austenitic 18/8 steels (similar to grade 304) stabilized through the addition of titanium (321) or niobium (347). These grades are used because they resist intergranular corrosion when heated in the carbide precipitation range of 425-850°C. Grade 321 is the preferred choice for applications in the temperature range up to approximately 900°C, offering a combination of high strength, scaling resistance, phase stability, and resistance to subsequent water corrosion.

Grade 321H is an improved version of 321 with a higher carbon content, providing increased high-temperature strength.

One limitation of Grade 321 is that titanium does not transfer well in high-temperature arcs, making it unsuitable as a welding material. In such cases, Grade 347, which uses niobium as a stabilizing element, is preferred as it can be transferred by the welding arc. Therefore, Grade 347 is the standard consumable for welding Grade 321. Grade 347 is only occasionally used as a base material.

Like other austenitic grades, 321 and 347 exhibit excellent forming and welding characteristics, making them easy to bend or roll. They also have exceptional toughness, even at low temperatures. Grade 321 is not recommended for decorative applications as it does not polish well.

For most product forms, Grade 304L is more readily available, so if post-weld intergranular corrosion resistance is the primary requirement, Grade 321 is generally preferred. However, if the operating environment exceeds approximately 500°C, Grade 304L is not the best choice due to its lower thermal strength.

ASTM A 213 321 Stainless Steel Tubing Mechanical Properties

Stainless Steel 321 Tube Chemical Composition

SS 321 Tubes for sale

SA 213 TP 321 Stainless Steel Tubing Specification

Check Dimensions & sizes of 321 SS Welded Tubing

Application:

• Food processing equipment, especially beer brewing, milk processing and wine making.
• Kitchen benches, sinks, sinks, equipment and appliances
• Building paneling, railings and decoration
• Chemical containers, including for transportation
• Heat exchanger
• Woven or welded screens for mining, quarrying and water filtration
• Threaded fasteners
• Spring
• Other​