304 Stainless Steel
304 stainless steel is a commonly used austenitic stainless steel grade, known for its excellent corrosion resistance, high-temperature strength, and versatility. It contains a minimum of 18% chromium and 8% nickel.Type 304 has a maximum carbon of 0.07%, along with small amounts of other elements such as manganese, silicon.Grade 304 steel is a standard "18/8" stainless.
Stainless steel 304, also known as SS304 or simply 304, is an austenitic stainless steel that is widely used in various applications such as commercial kitchens, food processing plants, chemical processing plants, and many more.
304 Stainless Steel Types
304 stainless steel is a common type of stainless steel that is widely used in various industries. Its high corrosion resistance, low maintenance cost, and excellent weldability make it an ideal material for different applications.There are different types of 304 stainless steel available in the market,the common types are Garde 304L and 304H:
- Grade 304L Stainless Steel
304L stainless steel is a low-carbon version of 304 stainless steel that is used in applications where welding is required. The reduced carbon content in type 304L stainless steel helps to minimize carbide precipitation, which can result in intergranular corrosion. 304L stainless is commonly used in welded components and piping systems.
- Type 304H Stainless Steel
304H stainless steel is a high-carbon version of 304 stainless steel with an increased amount of carbon content. The higher carbon content provides better strength, high-temperature resistance, and improved creep resistance. 304H steel is commonly used in high-temperature applications such as furnace parts, heat exchangers, and boiler components.
304 Stainless Steel Properties
Material 304 Chemical Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | |
| 304 | min. max. |
- 0.08 |
- 2.0 |
- 0.75 |
- 0.045 |
- 0.030 |
18.0 20.0 |
- | 8.0 10.5 |
- 0.10 |
| 304L | min. max. |
- 0.030 |
- 2.0 |
- 0.75 |
- 0.045 |
- 0.030 |
18.0 20.0 |
- | 8.0 12.0 |
- 0.10 |
| 304H | min. max. |
0.04 0.10 |
- 2.0 |
- 0.75 |
-0.045 | - 0.030 |
18.0 20.0 |
- | 8.0 10.5 |
- |
SS 304 Stainless Steel Mechanical Properties
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50 mm) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| 304 | 515 | 205 | 40 | 92 | 201 |
| 304L | 485 | 170 | 40 | 92 | 201 |
| 304H | 515 | 205 | 40 | 92 | 201 |
SUS 304 Material Physical Properties
| Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100 °C (J/kg.K) | Electrical Resistivity (nΩ.m) | |||
| 0-100 °C | 0-315 °C | 0-538 °C | at 100 °C | at 500 °C | |||||
|
304 /304L /304H |
8000 | 193 | 17.2 | 17.8 | 18.4 | 16.2 | 21.5 | 500 | 720 |
AISI 304 Material Equivalent Grades
| Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
| BS | En | No | Name | ||||
| 304 | S30400 | 304S31 | 58E | 1.4301 | X5CrNi18-10 | 2332 | SUS 304 |
| 304L | S30403 | 304S11 | - | 1.4306 | X2CrNi19-11 | 2352 | SUS 304L |
| 304H | S30409 | 304S51 | - | 1.4948 | X6CrNi18-11 | - | - |
304 Stainless Steel Magnetic
304 stainless steel is generally non-magnetic in its annealed state, although it can become slightly magnetic after cold working or when exposed to high temperatures.
SS304 Material Corrosion Resistance
304 stainless steel demonstrates excellent resistance to a wide range of corrosive environments, including atmospheric conditions, fresh water, and mild acids and alkalis. It is particularly resistant to corrosion from oxidation and chloride environments.
It is subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above 60 °C (approximate). Grade 304 is considered to be resistant to potable water up to approximately 200 mg/L chlorides at ambient temperatures, reducing to approximately150 mg/L at 60 °C.
AISI 304 Stainless Steel Formability and Fabrication
304 stainless steel exhibits good formability, enabling it to be easily shaped, bent, and fabricated. It can be welded using various methods, including TIG (Tungsten Inert Gas) welding, MIG (Metal Inert Gas) welding, and resistance welding.
Stainless 304 Oxidation Resistance
304 stainless steel exhibits good resistance to oxidation in intermittent service up to temperatures of around 870°C (1600°F) and continuous service up to approximately 925°C (1700°F). This makes it suitable for applications where exposure to high-temperature air or combustion gases is involved.
304 Steel Thermal Expansion
Like other stainless steel grades, 304 stainless steel has a relatively low coefficient of thermal expansion. This property helps reduce the risk of thermal stress and distortion when exposed to temperature variations.
|
0-100°C |
0-315°C |
0-538°C |
|
17.2 |
18.4 |
16.2 |
