What is AISI 303
AISI 303 (SUS 303) Grade Stainless Steel. Stainless steel type 1.4305 is popularly known as grade 303 stainless steel. Grade 303 is the most readily machinable of all the austenitic grades of stainless steel. The machinable nature of grade 303 is due to the presence of Sulphur in the steel composition. Whilst the Sulphur improves machining, it also causes a decrease in the corrosion resistance and a slight lowering of the toughness.
Chemical and physical properties
Sulphur additions to the composition act as initiation sites for pitting corrosion. This decreases the corrosion resistance of 303 stainless steel to less than that for 304. However corrosion resistance remains good in mild environments.
In chloride containing environments over 60°C, 303 stainless steel is subject to pitting and crevice corrosion. Grade 303 stainless is not suitable for use in marine environments.
Grade 303 stainless steel has good resistance to oxidation when intermittently exposed to temperature up to 760°C temperatures. It also has good oxidation resistance in continuous service to 870°C. This, however, is not recommended as 303 is sensitive to carbide precipitation with continuous use at 425-860°C.
Chemical Resistance Chart
» Meaning of symbol:
OK: Recommended. △: Must confirm if usable by testing in advanced. X: Not recommended.
» This chart only provides the result of a single chemical to material, if a client uses more than one kind of chemical at the same time, please choose material by experience.
» This chart is for reference only which is not applicable to all working environments. Please refer to design equipment according to practical experience.
| Category |
Name |
AISI316 |
Organic acids
|
Acetic acid |
OK |
| Acetic acid, glacial |
N/A |
| Acetic anhydride |
OK |
| Citric acid |
N/A |
Organic compound
|
Acetaldehyde |
OK |
| Acetone |
OK |
| Methyl alcohol |
OK |
| Aniline |
OK |
| Benzaldehyde |
OK |
| Benzene |
N/A |
| Benzyl alcohol |
N/A |
| Benzyl chloride |
N/A |
| Corn oil |
N/A |
| Ethanol |
OK |
| Ethylene glycol |
OK |
| Fatty acid |
N/A |
| Formaldehyde |
△ |
| Formic acid |
OK |
| Hexane |
N/A |
| Lactic acid |
OK |
| Methanol |
OK |
| Paraffin oil |
N/A |
| Petroleum |
N/A |
| Phenol |
OK |
| Propane, liq |
OK |
| Propanol |
OK |
| Stearic acid |
N/A |
| Tannic acid |
N/A |
| Tartaric acid |
N/A |
| Toluene |
OK |
| Urea |
N/A |
Inorganic compound
|
Ammonia |
OK |
| Ammonium chloride |
N/A |
| Ammonium hydroxide |
OK |
| Ammonium nitrate |
N/A |
| Ammonium sulfate |
N/A |
| Aqua regia |
N/A |
| Barium chloride |
OK |
| Barium hydroxide |
OK |
| Brine |
N/A |
| Calcium Chloride |
N/A |
| Calcium hydroxide |
N/A |
| Carbonic acid |
N/A |
| Chloric acid |
N/A |
| Chlorine |
OK (wet) |
| Detergent |
OK |
| Hydrobromic acid |
N/A |
| Hydrochloric acid |
N/A |
| Hydrofluoric acid |
△ (50%) |
| Hydrogen peroxide |
OK (30%) |
| Nitric acid |
OK (10%)
OK (concentrated) |
| Phosphoric acid |
OK (10%)
OK (concentrated) |
| Potassium hydroxide |
OK (50%) |
| Potassium nitrate |
△ |
| Potassium sulfate |
OK |
| Sodium carbonate |
OK |
| Sodium hydroxide |
OK |
| Sodium nitrate |
N/A |
| Sulfuric acid |
OK (concentrated) |
| Sulfur dioxide |
OK (liquid) |