321 Stainless Steel: Composition, Physical Properties and Application

Looking for a high-performance stainless steel that can withstand extreme temperatures and resist corrosion? Look no further than 321 stainless steel!

With its exceptional resistance to acid and alkali corrosion, this steel is the perfect choice for a wide range of applications, from aircraft exhaust systems to heat exchangers. But what makes 321 stainless steel so special?

In this blog post, we’ll take a closer look at the composition and properties of this remarkable material, and explore its many uses in the world of engineering and manufacturing.

So sit back, relax, and get ready to discover the power of 321 stainless steel!

Introduction to 321 Stainless Steel

321 stainless steel is created by adding a titanium element to the base composition of 304 stainless steel. Its performance is highly similar to that of 304 stainless steel. The addition of titanium results in exceptional resistance to acid and alkali corrosion. Even a small amount of titanium (around 1%) added to stainless steel can significantly enhance its rust resistance.

Austenitic stainless steel is prone to sensitization when exposed to temperatures between 450 ℃ and 850 ℃.

During sensitization, carbides, mainly chromium carbide (C23C6), precipitate along grain and twin boundaries, which results in damage to the neighboring alloy elements. This leads to intergranular corrosion in specific corrosive environments.

321 stainless steel is capable of withstanding the formation of chromium carbide between 426 ℃ and 815 ℃ due to the addition of titanium as a stabilizing element. As a result, it exhibits better resistance to intergranular corrosion, high temperature performance, and higher resistance to creep and stress fractures than 304 and 304L.

Furthermore, 321 also has excellent low-temperature toughness, formability, and welding properties. It does not require annealing after welding.

321 Stainless steel composition

StandardGB/T20878ASTM A276JIS G4303DIN EN10088-3
Grade  06Cr18Ni11Ti(0Cr18Ni10Ti)S32100321SUS 321X6CrNiTi18-101.4541

Physical property

Density (g/cm3) 20 ℃


Melting point (℃)


Specific heat capacity [kJ/(kgK)] 0~100 ℃


Thermal conductivity [W/(m-K)]





Linear expansion coefficient (10-6/K)





Resistivity (Ωmm2/m) 20 ℃


Longitudinal elastic modulus (kN/mm2) 20 ℃



Slightly magnetic after cold deformation

321 stainless steel application scenario

The addition of titanium to 321 stainless steel enhances its suitability for high-temperature applications, making it a better choice than 304 stainless steel, which can experience sensitization reactions, and 304L stainless steel, which may not have sufficient high-temperature strength.

Common uses for 321 stainless steel plate and tube products include thermal expansion joints, corrugated pipes, components for aircraft exhaust systems, casings for heating elements, furnace body components, and heat exchangers.

Professional Insights

Get Expert Advice on Metalworking Machines

Let our experts help you choose the right metalworking machine for your needs.

About The Author

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top