321/321H

Applications

•  Aerospace – piston engine manifolds
•  Chemical Processing
•  Expansion Joints
•  Food Processing – equipment and storage
•  Petroleum Refining – polythionic acid service
•  Waste Treatment – thermal oxidizers

Standards

• ASTM/ASME: UNS S32100 / S32109
• EURONORM:  321 / 1.4541
• EURONORM: 321H / 1.4878

Corrosion Resistance

•  exhibits good general corrosion resistance that is comparable to 304.
•  developed for use in the chromium carbide precipitation range of 1800 – 1500°F (427 – 816°C) .
•  can be used in most diluted organic acids at moderate temperatures .
•  can be used in pure phosphoric acid at lower temperatures.
•  can be used in up to 10% diluted solutions at elevated temperatures.
•  resists polythionic acid stress corrosion cracking in hydrocarbon service.
•  utilized in chloride or fluoride free caustic solutions at moderate temperatures.
•  does not perform well in chloride solutions, even in small concentrations, or in sulfuric acid service.

Processing

• Grade 321/H can be easily welded and processed by standard shop fabrication practices.

Hot Forming

•  Working temperatures of 2100 – 2300°F (1149 – 1260°C) are recommended for forging, upsetting and other hot working processes.
•  Alloy not suitable for work at temperatures below 1700°F (927°C).
•  Material must be water quenched or fully annealed after working to re-attain maximum corrosion resistance.

Cold Forming

•  Quite ductile and forms easily.

Welding

•  Readily welded by most standard processes.
•  Post weld heat treatment is not necessary

Machining

•  Hardening rate of 321 makes it less machinable than 410 stainless steel, but similar to 304

Chemical Properties

Mechanical Properties

Physcial Properties