Stainless 321 is a heat resistant, titanium stabilized, austenitic alloy that's commonly used for service in the 1000-1600 temperature range. 321 stainless is primarily used in applications that involve continuous and intermittent service temperatures within the carbide precipitation range of 800-1500. Type 321 is similar to type 304 stainless 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 service conditions. In order to provide optimum resistance to intergranular corrosion and to polythionic acid stress corrosion cracking in service temperatures at 1500-1650 an air cool may be used.
What are the characteristics of 321H stainless steel ?
Oxidation resistant to 1600
Stabilized against weld heat affected zone (HAZ) intergranular corrosion
Resists polythionic acid stress corrosion cracking
Stainless 321H 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
Expansion joints
Thermal oxidizers
Refinery equipment
High temperature chemical process equipment
Mechanical Properties Average Elevated Temperature Tensile Properties
Temperature
|
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 | |