321 Stainless Steel UNS S32100

Strip, Coil, Foil, Wire, UNS S32100, AMS 5510

Applications

Aircraft collector rings, exhaust stacks, carburetor air intensifier tubes, exhaust manifolds, flexible couplings, jet engine parts, mufflers, pressure vessels, tubing, fasteners, flexible metal hose and bellows

Description

Type 321 is an austenitic chromium-nickel stainless steel containing Titanium which is recommended for parts fabricated by welding which cannot subsequently be annealed. Type 321 is a stabilized austenitic stainless steel similar to type 304 but with a titanium addition. This titanium addition reduces or prevents carbide precipitation during welding and in 800 - 1500 °F (427 - 816 °C) service. It also improves the elevated temperature properties of the alloy. Type 321 provides excellent resistance to oxidation and corrosion and possesses good creep strength.

Chemistry Typical

Carbon: 0.08 max
Manganese: 2.00 max
Silicon: 0.75 max
Chromium: 17.00-19.00
Nickel: 9.00-12.00
Molybdenum: 0.75 max
Phosphorus: 0.045 max
Sulfur: .030 max
Copper: 0.75 max
Nitrogen: .010 max
Titanium: 5x (Carbon+ Nitrogen) min-0.70 max
Iron: Balance

Physical Properties

Density: 0.29 lbs/in3 9.01 g/cm3

Electrical Resistivity: microhm-in (microhm-cm): 68 °F (20 °C): 28.4 (72)

Specific Heat: BTU/lb/°F (kJ/kg•K):
32 - 212 °F (0 - 100 °C): 0.12 (0.50)

Thermal Conductivity: BTU/hr/ft2/ft/°F (W/m•K):
At 212 °F (100 °C): 9.3 (16.0)
At 932 °F (500 °C): 12.8 (22.0)

Mean Coefficient of Thermal Expansion: in/in/°F (µm/m•K)
32 - 212 °F (0 - 100 °C): 9.2 x 10·6 (16.6)
32 - 600 °F (0- 315 °C): 9.5 x 10·6 (17.1)
32 - 1000 °F (0 - 538 °C): 10.3 x 10·6 (18.5)
32 - 1200 °F (0 - 649 °C): 10.7 x 10·6 (19.3)
32 - 1500 °F (0 - 873 °C): 11.2 x 10·6 (20.2)

Modulus of Elasticity: ksi (MPa)
28 x 103 (193 x 103) in tension
11 .2 x 103 (78 x 103) in torsion

Magnetic Permeability: H = 200 Oersteds: Annealed < 1.02 max
Melting Range: 2500 - 2550 °F (1371 - 1400 °C)

Forms

Coil - Strip, Foil, Ribbon Wire - Profile, Round, Flat, Square

Mechanical Properties at Room Temperature Properties: Annealed

Ultimate Tensile Strength: 75 KSI min (515 MPa min)
Yield Strength (0.2% Offset): 30 KSI min (250 MPa min)
Elongation: 40% min
Hardness: Rb 95 max

Properties: Tempered

Type 321 can be cold rolled to various tempers. Contact Ulbrich Technical Services for additional information.

Additional Properties

Corrosion Resistance

Type 321 has excellent corrosion resistance equivalent to type 302 or 304 in the annealed condition and superior if a weldment in these grades has not been post-weld annealed or if the application involves service in the 800 °F - 1600 °F range.

Finishes

# 1 - Hot rolled annealed and descaled. It is available in strip, foil and ribbon. It is used for applications where a smooth decorative finish is not required.
# 2D - Dull finish produced by cold rolling, annealing and descaling. Used for deep drawn parts and those parts that need to retain lubricants in the forming process. # 2B - Smooth finish produced by cold rolling, annealing and descaling. A light cold rolling pass is added after anneal with polished rolls giving it a brighter finish than 2D.
#BA- Bright annealed cold rolled and bright annealed
#CBA- Course bright annealed cold rolled matte finish and bright anneal
#2 - Cold Rolled
# 2BA- Smooth finish produced by cold rolling and bright annealing. A light pass using highly polished rolls produces a glossy finish. A 2BA finish may be used for lightly formed applications where a glossy finish is desired in the formed part. Polished - Various grit finish for specific polish finished requirements.
* Not all finishes are available in all alloys - Contact Ulbrich Sales for more information.

Wire Finishes

XC - Extra clean bright annealed or bright annealed and cold rolled Grease - Ultra-bright finish (for decorative applications) Soap - Soap is not removed from tempered wire to act as a lubricant. * Contact Ulbrich Wire for custom wire finishes.

Cold Forming

Type 321 can be readily formed and drawn. Like most other austenitic stainless steels, type 321 work hardens and may require annealing after severe forming.

Heat Treatment

Type 321 is non hardenable by heat treatment and can only be hardened by cold working.

Stress Relieving

Heat to 1290 °F (700 °C) for 1 to 2 hours and then air cool.

Welding

Type 321 is weldable by common fusion and resistance methods. Use type 347 filler rod or electrodes. For best results refer to: SSINA's "Welding of Stainless Steels and Other Joining Methods".

Limitation of Liability and Disclaimer of Warranty: In no event will Ulbrich Stainless Steels & Special Metals, Inc., be liable for any damages arising from the use of the information included in this document or that it is suitable for the 'applications' noted. We believe the information and data provided to be accurate to the best of our knowledge but, all data is considered typical values only. It is intended for reference and general information and not recommended for specification, design or engineering purposes. Ulbrich assumes no implied or express warranty in regard to the creation or accuracy of the data provided in this document.