STAINLESS STEEL - 303 Stainless Steel
Type 303
- Austenitic Stainless Steel
- Excellent machining characteristics
- Free machining version of Types 302 and 304 is used for parts requiring extensive machining
- Annealed condition is non-magnetic
- Slightly magnetic when cold worked
- Good corrosion resistance
- Good oxidation resistance up to 1700 degrees F
Type 303 Se
- Basically same as 303
- Obtains free-machining characteristics by the addition of selenium rather than sulfur
- Selenium produces better surface finish
- Selenium improves formability and weldability
Specifications: Types 303 and 303 Se are covered by the following specifications:
Type 303
- AMS 564OG
- ASTM A314-63
- ASTM A320-65
- ASTM 581-67
- ASTM 582-67
- QQ-S-764A
- MIL-S-862B
Type 303 Se
- AMS 5640G
- AMS 5641A
- AMS 5738
- ASTM A314-63
- ASTM A230-65
- ASTM A581-67
- ASTM 582-67
Standard Heat Treatments
- Anneal: Heat to 1900 - 2050 F and water quench
- Harden: Types 303 and 303 Se cannot be hardened by heat treatment
Machinability
- Excellent machinability
- Surface finish on parts made of 303 Se is better than that of regular 303
Corrosion Resistance
- Excellent corrosion resistance
- Effectively resist attack in atmospheric exposures, sterilizing solutions, most organic and many inorganic chemicals, most dyes nitric acid and foods
- For best corrosion resistance finished parts should be free from scale and foreign particles
Formability
- Type 303 limited formability because of its sulfur content
- Type 303 Se has better formability but it should be limited to mild forming operations
Forgeability
- Types 303 and 303Se should be heated slowly to 2000-2150 F
- Soaked for a sufficient time then raised to 2200 - 3250 F
- They should not be forged below 1700 F
Weldability
- only fair weldability
- can be welded using proper procedures
- Weldability can be improved by using methods that minimize dilution of the weld metal with the melted base metal
- Reducing the time that weld are in the hot-short temperature range and use of Type 312 (29-9) filler metal helps obtain satisfactory results
PROPERTY OF 304 AND 304L
Type 304 |
Type 304L |
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Sheet & Strip |
Bar & Wire |
Sheet & Strip |
Bar & Wire |
|
| Ultimate tensile strength, psi | 85,000 | 85,000 | 80,000 | 80,000 |
| .2% Yield strength, psi | 35,000 | 35,000 | 30,000 | 30,000 |
| Elongation, % om 2" | 55 | 60 | 55 | 60 |
| Rockwell hardness | B80 | B80 | N75 | B75 |
| Reduction of area, % | NA | 70 | NA | 70 |
| Impact strength, Izod V Notch, ft-lbs | NA | 100-120 | NA | 100-120 |
| Endurance limit, psi | NA | 34,000 | NA | 34,000 |