SAE 304 stainless steel: Difference between revisions
== Mechanical Properties ==
== Mechanical Properties ==
304 stainless steel cannot be heat treated, instead it can be strengthened by cold working. It is weakest in the annealed condition, and is strongest in the full-hard condition. The tensile yield strength ranges from {{cvt|30000|to|153000|psi|MPa}}.
304 stainless steel cannot be heat it can be strengthened by cold working. It is weakest in the annealed condition, and is strongest in the full-hard condition. The tensile yield strength ranges from {{cvt|30000|to|153000|psi|MPa}}.
The density is {{cvt|0.286|lb/in3|kg/m3}}, and it’s modulus of elasticity ranges from {{cvt|26.6|to|29.0|e6psi|GPa}}.{{cite book
The density is {{cvt|0.286|lb/in3|kg/m3}}, and modulus of elasticity ranges from {{cvt|26.6|to|29.0|e6psi|GPa}}.{{cite book
| title = MIL-HDBK-5J
| title = MIL-HDBK-5J
| publisher = United States Department of Defense
| publisher = United States Department of Defense
Most common stainless steel
SAE 304 stainless steel is the most common stainless steel. The steel contains both chromium (between 18% and 20%) and nickel (between 8% and 10.5%)[1] metals as the main non-iron constituents. It is an austenitic stainless steel, and is therefore not magnetic. It is less electrically and thermally conductive than carbon steel. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes.[1]
The composition was developed by W. H. Hatfield at Firth Brown in 1924 and was marketed under the trade name “Staybrite 18/8”.[2]
It is specified by SAE International as part of its SAE steel grades. It is also known as:[3]
- 4301-304-00-I and X5CrNi18-9, the ISO 15510 name and designation.
- UNS S30400 in the unified numbering system.
- A2 stainless steel outside the US, in accordance with ISO 3506 for fasteners.[4]
- 18/8 and 18/10 stainless steel (also written 18-8 and 18-10) in the commercial tableware and fastener industries.
- SUS304 the Japanese JIS G4303 equivalent grade.
- 1.4301, the EN 10088 equivalent.[5]
- 06Cr19Ni10 and ISC S30408, the equivalent in Chinese GB/T 20878 and GB/T 17616 nomenclature.
Chemical composition[edit]
| Standard | AISI (UNS) | C, ≤ | Si, ≤ | Mn, ≤ | P, ≤ | S, ≤ | Cr | Ni |
|---|---|---|---|---|---|---|---|---|
| ASTM A276/A276M | 304 (S30400) | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 18.0-20.0 | 8.0-11.0 |
Corrosion resistance[edit]
304 stainless steel has excellent resistance to a wide range of atmospheric environments and many corrosive media. It is subject to pitting and crevice corrosion in warm chloride environments and to stress corrosion cracking above about 60°C. It is considered resistant to pitting corrosion in water with up to about 400 mg/L chlorides at ambient temperatures, reducing to about 150 mg/L at 60°C.
304 stainless steel is also very sensitive at room temperature to the thiosulfate anions released by the oxidation of pyrite (as encountered in acid mine drainage) and can undergo severe pitting corrosion problems when in close contact with pyrite– or sulfide-rich clay materials exposed to oxidation.[citation needed]
For more severe corrosion conditions, when 304 stainless steel is too sensitive to pitting or crevice corrosion by chlorides or general corrosion in acidic applications, it is commonly replaced by 316 stainless steel.
304 and 302 Stainless Steels are subject to chloride stress fracture failure when used in tropical salt water conditions such as oil or gas rigs. 316SS is the preferred alloy for these conditions.
Mechanical Properties[edit]
304 stainless steel cannot be heat treated—instead it can be strengthened by cold working. It is weakest in the annealed condition, and is strongest in the full-hard condition. The tensile yield strength ranges from 30,000 to 153,000 psi (210 to 1,050 MPa).
The density is 0.286 lb/cu in (7,900 kg/m3), and its modulus of elasticity ranges from 26.6×106 to 29.0×106 psi (183 to 200 GPa).[7]
Applications[edit]
304 stainless steel is used for a variety of household and industrial applications such as food handling and processing equipment, screws,[4] machinery parts, utensils, and exhaust manifolds. 304 stainless steel is also used in the architectural field for exterior accents such as water and fire features. It is also a common coil material for vaporizers.
Early SpaceX Starships used SAE 301 Stainless Steel in their construction,[8] before moving over to SAE 304L for the SN7 test tank[9] and Starship SN8 in 2020.[10]
304 stainless steel was used to clad the Gateway Arch in St. Louis, Missouri.[11][12]
Carbon content[edit]
304, 304H, and 304L all possess the same nominal chromium and nickel content and…
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