Stainless steel plate flanges 1.4541 / 321

What are stainless steel plate flanges 1.4541 / 321?

Stainless steel plate flanges 1.4541 / 321 are pipe and component flanges manufactured from grade 1.4541 stainless steel (commonly known as AISI 321 or EN X6CrNiTi18-10). This is an austenitic, titanium‑stabilised, acid‑resistant stainless steel. In plain terms: the steel contains added titanium to reduce the risk of intergranular corrosion during welding or when exposed to elevated temperatures. Plate flanges are typically produced from flat stainless plate and then machined or pressed to form the required flange shape.

Material and standards

The material is often referenced by several equivalent designations so you may see it listed as:

• European (EN): 1.4541 / X6CrNiTi18-10
• US (AISI/ASTM): AISI 321 / ASTM 321
• Common description: titanium‑stabilised austenitic stainless steel, acid‑resistant

This grade provides improved resistance to intergranular corrosion after exposure to temperatures at which chromium carbides can form, which is why it is specified for welded components such as flanges.

Typical uses and applications

Stainless steel plate flanges 1.4541 / 321 are used wherever corrosion resistance together with good performance at elevated temperatures is required. Typical applications include:

• Heat exchangers and boiler components
• Acid and chemical tanks, absorption towers and process pipework in chemical and nitrogen industries
• Pumps, agitators and fittings in the pharmaceutical and paint industries
• Food industry equipment exposed to aggressive preservatives (for example salt)
• Exhaust systems and certain automotive components where high‑temperature stability matters
• General fabrication and repair work where welded joints are common

Who buys these flanges?

Customers include mechanical and pipework contractors, fabricators, maintenance teams, engineers and procurement specialists in industries such as chemical processing, food and beverage, pharmaceutical manufacturing, automotive, HVAC, and light offshore or marine applications. They are suitable for both small workshop projects and larger industrial installations.

Benefits and limitations

• Benefits: very good weldability with common welding methods; good resistance to a range of aggressive agents (including many organic acids and hot hydrocarbons); better protection against intergranular corrosion after heating than non‑stabilised 304/1.4301.
• Limitations: while 1.4541 offers good general corrosion resistance, it is not as resistant to chloride‑induced pitting and crevice corrosion as molybdenum‑containing grades such as 316/1.4401. For persistent seawater or high‑chloride environments you should consider 316 or other specialist alloys.

Fabrication, welding and inspection

Grade 1.4541 machines and welds well using standard techniques. The titanium stabilisation reduces the need for post‑weld solution annealing to avoid intergranular attack in many common applications. As with any stainless material, correct selection of fasteners, gaskets and welding procedures is important to ensure long service life.

Choosing the right flange

When selecting plate flanges 1.4541 / 321, consider the operating environment (chemical exposure, temperature, chloride content), mechanical loads and welding/installation method. If in doubt, our technical team can advise whether 1.4541 is the best choice or if an alternative stainless grade such as 1.4301 (304) or 1.4401 (316) would be more appropriate.

If you need help specifying sizes, pressure ratings or finish (e.g. machined face, surface polish), contact us with your application details and we’ll recommend the correct flange solution.