Stainless steel is a high-strength, corrosion-resistant material comprised of iron and chromium, and other metals in certain applications. Because of its many outstanding properties, stainless steel is used widely across the world in almost every industry. For this blog post, we will focus on the key properties and applications of 321 stainless steel, which is an austenitic 18/8 chromium-nickel alloy commonly used in demanding and high-temperature environments.

Key Properties of 321 Stainless Steel

321 stainless steel is used in applications from 400oC to 900oC. Still, it is important to note that it should not be used as a welding consumable because the titanium within will not transfer efficiently across a high-temperature arc. Additionally, 321 stainless steel shouldn’t be used in cosmetic architecture because it does not polish well.

Composition and Chemical Properties

321 stainless steel is manufactured with titanium but based on 304 stainless steel. The added titanium enhances its corrosion and heat resistance, among othe rproperties.

UNS NoS32100
Carbon (C)0.08
Silicon (Si)0.75
Manganese (Mn)2.00
Phosphorus (P)0.045
Sulphur (S)0.030
Chromium (Cr)17.00 – 19.00

Mechanical Properties

DescriptionType 321
Proof stress 0.2% (MPa)205
Tensile strength (MPa)515
Elongation A5 (%)40
HardnessHB: 217HRB: 95

Corrosion Resistance Properties

As mentioned, type 321 offers excellent corrosion-resistant properties that enable its use in harsh environments and high-temperature applications. It’s key features include its resistance to crevice corrosion, intergranular corrosion and pitting. 

Heat Resistance Properties

Type 321 has outstanding heat resistance in comparison to other stainless steels grades. It can operate in temperatures up to 900°C while resisting oxidation and maintaining optimal stability.

Applications of 321 Stainless Steel

321 stainless steel is used in so many different applications because of its resistance to corrosion and ability to withstand high temperatures in harsh environments. They are used to manufacture a range of components in the transportation industries and are frequently used in equipment that handles corrosive or harmful chemicals. Below, we outline a few key applications of 321 stainless steel.

  • Aerospace industry: To manufacture exhaust systems and heat exchangers.
  • Automotive industry: In catalytic converters and exhaust systems.
  • Chemical processing industry: For pipes, tanks and valves in chemical handling.
  • Food processing industry: To manufacture food processing equipment.
  • Medical industry: In medical equipment like dental tools and surgical implants.
  • Petrochemical industry: In boilers, heat exchangers, and pipes.

Masteel and 321 Stainless Steel

Masteel is a UK steel provider with a global client base. We offer a wide range of steels for use across various industries, as well as profiling and testing services for our products. One of the stainless steel grades we offer is type 321.

Contact a member of Masteel today to learn more about 321 stainless steel or to make a purchase.