321 Stainless Steel Overview
Stainless Steel 321 is a heat resistant, titanium stabilized, austenitic alloy that's commonly used for service in the 1000°-1600°F temperature range. 321 stainless steel is primarily used in applications that involve continuous and intermittent service temperatures within the carbide precipitation range of 800°-1500°F. Type 321 stainless steel is similar to type 304 stainless steel but with a titanium addition of at least five times the carbon content. This titanium addition reduces or prevents carbide precipitation during welding and in the 800°-1500°F service conditions. In order to provide optimum resistance to intergranular corrosion and to polythionic acid stress corrosion cracking in service temperatures at 1500°-1650°F an air cool may be used.
What are the characteristics of 321 Stainless Steel?
- Oxidation resistant to 1600°F
- Stabilized against weld heat affected zone (HAZ) intergranular corrosion
- Resists polythionic acid stress corrosion cracking
Stainless Steel 321 Chemical Composition, %
Cr
|
Ni
|
Mo
|
Cu
|
Ti
|
C
| |
|---|---|---|---|---|---|---|
MIN
|
17.0
|
9.0
|
-
|
-
|
5x(C+N)
|
-
|
MAX
|
19.0
|
12.0
|
0.75
|
0.75
|
0.70
|
0.08
|
Mn
|
Si
|
P
|
S
|
N
|
Fe
| |
MIN
|
-
|
0.25
|
-
|
-
|
-
|
-
|
MAX
|
2.0
|
1.0
|
0.04
|
0.03
|
0.1
|
Bal
|
What applications might 321 Stainless Steel be used?
- Aircraft piston engine manifolds and exhaust stacks
- Stainless Steel Pipes
- Oil and gas equipment
- Offshore technology
- Seawater desalination plants
- Chemical industry, especially when handling chlorides
- Flue-gas cleaning
- Desalination plants and seawater systems
- Pulp and paper industry
- Cargo tanks and pipe systems in chemical tankers
- Firewalls and blast walls on offshore platforms
- Bridges
- Stainless Steel Pipe Fittings
- Pressure vessels, reactor tanks, and heat exchangers
- Rotors, impellers and shafts
- Stainless Steel Flanges
Mechanical PropertiesAverage Elevated Temperature Tensile Properties
Temperature, °F |
Ultimate Tensile Strength, ksi
|
.2% Yield Strength, ksi
|
|---|---|---|
68
|
84
|
38
|
400
|
62
|
20.5
|
600
|
62
|
18
|
800
|
62
|
17
|
1000
|
59.5
|
16.5
|
1200
|
45.5
|
16
|
1400
|
27.5
|
14
|
Welding Stainless Steel 321
321 Stainless Steel is readily welded by all common methods including submerged arc. Appropriate weld fillers are most often specified as AWS E/ER 347 or E/ER 321.
This alloy is generally considered to have comparable weldability to 304 and 304L stainless steel with the main difference being the titanium addition which reduces or prevents carbide precipitation during welding.
321 Stainless is available in the following forms at Yaang
- Stainless Steel Elbows
- Stainless Steel Tees
- Stainless Steel Bars
- Stainless Steel Pipes
- Stainless Steel Tubes
- Stainless Steel Flanges (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
- Stainless Steel U Tubes
- Stainless Steel Concentric Reducer
- Stainless Steel Pipe Fittings
