Alloy 302 is a variations of the 18% chromium / 8% nickel austenitic alloy, which is the most familiar and the
most frequently used in the stainless steel family. Alloy 302 is a slightly higher carbon version of 304, often
found in strip and wire forms. It is a tough, ductile grade that demonstrates comparable corrosion resistance,
is non-magnetic, and is not hardenable by heat treatment. Alloy 302 is usually used in its annealed condition
and has a high ease of fabrication and formability.
Specifications: UNS S30200
Applications:
Although many applications have shifted to 304 and 304L due to advances in melting technology, availability,
and cost, Alloy 302 is still used in a variety of industries. Some examples include:
Stamping
Spinning
Wire forming
Formed into all types of washers, springs, screens, and cables
Food and beverage industry
Pressure containing applications
Sanitary or cryogenic applications
Some examples of products that are partially or completely constructed of 302 include:
Blenders
Counters
Dish racks
Dishwashers
Refrigerators
Washing machines
Standards:
ASTM/ASME: UNS S30200
EURONORM: FeMi35Cr20Cu4Mo2
DIN: 2.4660
Corrosion Resistance
Provides useful resistance to corrosion on a wide range of moderately oxidizing to moderately reducing
environments
The 18 -19% of chromium which this alloy contains provides resistance to oxidizing environments such as
dilute nitric acid.
Resistant to moderately aggressive organic acids such as acetic, and reducing acids such as phosphoric.
The 9-11% of nickel contained in this alloy provides resistance to moderately reducing environments.
Machinability
Slow speeds and high feeds will overcome this alloy’s tendency to work-harden
Due to gummy chips, it is recommended that chip breakers are used on all tooling
Weldability
Can best be welded by resistance or shielded fusion methods
Post weld annealing dissolves the chromium carbide and is recommended for maximum resistance to
intergranular attack
Hot Working
Uniform heating to 2100oF will allow this allow to be forged, upset and headed successfully
Do not work below 1700oF
Cold Working
Will dramatically increase the hardness of this material; however, it is quite ductile and may readily be drawn,
spun and upset
Causes alloy 302 to become magnetic
Post-fabrication annealing is necessary to retain maximum corrosion resistance and a non-magnetic condition
Chemical Properties:
| C | Mn | Si | P | S | Cr | Ni | N | |
|---|---|---|---|---|---|---|---|---|
| 302 | max: 0.15 | max:2.0 | max: 0.75 | max: 0.045 | max: 0.03 | min: 17.0 max: 19.0 | min: 8.0 max: 10.0 | max: 0.10 |
Mechanical Properties:
| Grade | Tensile Strength ksi (min) | Yield Strength 0.2% ksi (min) | Elongation % | Hardness (Rockwell B) MAX |
|---|---|---|---|---|
| 302 | 75 | 30 | 40 | 92 |
Physical Properties:
| Density lbm/in3 | Thermal Conductivity (BTU/h ft. °F) | Electrical Resistivity (in x 10-6) | Modulus of Elasticity (psi x 106 | Coefficient of Thermal Expansion (in/in)/ °F x 10-6 | Specific Heat (BTU/lb/ °F) | Melting Range (°F) |
|---|---|---|---|---|---|---|
| at 68°F: 0.285 | 9.4 at 212°F | 72.0 at 70°F | 28 | 9.6 at 32 – 212°F | 0.1200 at 32°F to 212°F | 2500 to 2590 |
| 12.4 at 932 °F | 10.2 at 32 – 1000°F | |||||
| 10.4 at 32 – 1500°F |
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