Customization: | Available |
---|---|
Type: | Steel Plate |
Standard: | ASTM, AISI, GB, JIS, DIN |
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The machineable nature of Grade 303 stainless steel is due to the presence of Sulphur in the steels composition. Whilst the Sulphur improves machining, it also causes a decrease in the corrosion resistance and a slight lowering of the toughness. The corrosion resistance of grade 303 stainless steel is lower than that for 304. The toughness is still excellent as with other austenitic grades.
Chemical composition for stainless steels alloy 303
% |
303 |
C |
0-0.10 |
Mn |
0-2.0 |
Si |
0-1.0 |
P |
0-0.4 |
S |
0-0.15 |
Cr |
17-19 |
Ni |
8-10 |
Fe |
balance |
Grade | UNS | DIN | EN | AMS | ASTM | BS | |
303 |
S30300 |
- | 1.4305 | 303S31 |
Mechanical properties for stainless steel alloy 303 bar
Grade |
303 |
Tensile Strength (MPa) |
500-750 MPa |
Proof Stress (MPa) |
190 Min MPa |
Elongation A5 mm |
35 Min % |
Hardness Brinell |
230 Max HB |
Physical properties for stainless steel alloy 303
Property |
Value |
Density |
8.03 kg/m3 |
Melting Point |
1455°C |
Modulus of Elasticity |
193 GPa |
Electrical Resistivity |
0.72 x 10-6 Ω.m |
Thermal Conductivity |
16.3 W/m.K |
Thermal Expansion |
17.3 x 10-6/K |
Sulphur additions to the composition act as initiation sites for pitting corrosion. This decreases the corrosion resistance of grade 303 stainless steel to less than that for 304. However corrosion resistance remains good in mild environments.
In chloride containing environments over 60°C, grade 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.
Type 303 is not readily cold workable. Some cold working is possible but sharp bending should not be attempted.
Fabrication methods, like forging, that involve hot working like should occur after uniform heating to 1149-1260°C. The fabricated components should then be rapidly cooled to ensure maximum corrosion resistance.
Grade 303 stainless steel cannot be hardened by heat treatment.
Solution treatment or annealing can be done by rapid cooling after heating to 1010-1120°C.
Grade 303 stainless steel has excellent machinability. Machining can be enhanced by adhering to the following rules:
The sulphur addition present in Grade 303 stainless steel results in poor weldability. If Grade 303 stainless steel must be welded the recommended filler rods or electrodes are grades 308L and 309 stainless steels. For maximum corrosion resistance, the welds must be annealed.