321 stainless steel pipe properties and characteristics

321 stainless steel pipe properties and characteristics

TP 321 is a stable stainless steel whose main advantage is its excellent resistance to intergranular corrosion after exposure to chromium carbide precipitation temperatures ranging from 800°F to 1500°F (427°C to 816°C). Alloy 321 stainless steel tube is stabilized to form chromium carbide by adding titanium.

321 321H Stainless steel is a titanium-stabilized version of 304 for specific applications in the sensitization temperature range. Its resistance to sensitization, coupled with its higher strength at high temperatures, makes it suitable for applications where 304 will be sensitized or 304L thermal strength is insufficient. Weld rot intergranular corrosion does not occur when exposed to a mildly corrosive environment. However, welding 321 should never be used in a highly oxidized environment, as it is susceptible to "knife line" erosion. However, in operating temperatures of more than 500° C, the 321 is a better choice and therefore has its own advantages. Alloy 321 stainless steel pipe due to its good mechanical properties, also conducive to high temperature use. Alloy 321 stainless steel has higher creep and stress fracture characteristics than alloy 304, and alloy 304L in particular can also be considered for sensitive and intergranular corrosion problems.

321 321H Stainless steel is basically made of 304 stainless steel. They differ in that very little titanium is added. The real difference is their carbon content. The higher the carbon content, the greater the yield strength. 321 stainless steel has advantages in high temperature environments due to its excellent mechanical properties. Compared with 304 alloy, 321 stainless steel has better ductility and stress fracture resistance. In addition, 304L can also be used to resist sensitization and intergranular corrosion.

Grade 304L is more readily available in most product forms, so if resistance to post-weld intergranular corrosion is only required, 321 is usually preferred. However, the 304L has a lower thermal strength than the 321, so it is not the best choice if it is required to withstand operating environments above about 500°C.