Stainless steel 304 is one of the most common types of stainless steel, also known in the industry as 18 /8 stainless steel, meaning it contains more than 18% chromium (Cr) and more than 8% nickel (Ni), and is widely used in the industrial and furniture decoration industry and the food and medical industry.
In addition to the common type, there are many extended types to suit various scenarios, such as the low carbon stainless steel 304L used for occasions where welding is required, the nitrogen-added (N) stainless steel 304N to increase the strength of the steel, and the high-temperature stainless steel 304H adapted to high-temperature environments.
304 Stainless Steel
304 stainless steel has national standards, American standards, Japanese standards, and European standards. First, called different, national standard 06Cr19Ni10, American standard ASTM304, European standard 1.4301, and Japanese standard SUS304. second, the elemental content is slightly different, the national standard, the Japanese standard chromium (Cr) content is between 18%-20%, nickel (Ni) content between 8%-10.5%, the American standard, the European standard chromium (Cr) content between 17.5%-19.5%. Nickel (Ni) content between 8%-10.5%.
The main difference is that the chromium (Cr) content requirements are different, American Standard, and European standard chromium (Cr) content as long as 17.5% or more even if the standard.
304 stainless steel there is another S30408 and 304 grade is the same, the difference is that the production standard is different.S30408 is by the GB-T 24511-2017 “Pressurized equipment with stainless steel and heat-resistant steel plate and strip” standard to produce.
Cold Rolled 304L/304 Stainless Steel Coil
304L Stainless Steel.
304L stainless steel national standard is S30403, which is the ultra-low carbon version of 304 stainless steel, lower carbon content brings better corrosion resistance and welding performance.304L stainless steel carbon content is reduced to less than 0.03%, based on enhancing the corrosion resistance of stainless steel, but also improve the 304 stainless steel between 450 ° C – 860 ° C, due to the precipitation of carbides caused by sensitization and Intergranular corrosion caused by welding, etc.
304L stainless steel in the heat-affected zone near the weld precipitation of carbide is reduced to a very small amount, limited to improve the resistance of stainless steel to intergranular corrosion and extend the service life of stainless steel welding contact. The extension properties of 304L stainless steel are better than 304 stainless steel, so it can be used instead of 304 in many cases. Of course, the price of 304L is relatively high.
304N Stainless Steel:
304N stainless steel is similar to the basic properties of 304 stainless steel, but 304N stainless steel it is a kind of stainless steel with nitrogen addition. Nitrogen is added to improve the strength of stainless steel, so 304N stainless steel is generally used in place of high requirements for cold forming.
304H Stainless Steel:
304H stainless steel is the national standard S30409, that is, the high carbon version of 304, with better high-temperature strength and oxidation resistance.304H stainless steel in the H refers to high temperature, high carbon content is the guarantee of high-temperature strength.304H stainless steel carbon content is not less than 0.04%.
304F Stainless Steel
304F stainless steel and 304 stainless steel are pretty much the same, the difference lies in the sulfur content, 304F stainless steel’s sulfur content is 0.03%, 304 stainless steel’s sulfur content is 0.001%, 304F stainless steel has a better cutting performance than 304 stainless steel, but 304F stainless steel rust resistance than 304 stainless steel is slightly worse.
304D Stainless Steel
First, the Cr Ni content is different. 304D stainless steel contains 2.8% nickel (Ni), 18% chromium (Cr), and 7% manganese, 304D stainless steel is not 304 stainless steel material. Second, corrosion resistance is different, 304D stainless steel corrosion resistance is worse than 304 stainless steel. Third, the price is different. 304D stainless steel price is cheaper than 304 stainless steel.
Difference Between 304, 304L, 304N, 304H, 304F, 304D Stainless Steel
Chemical Composition
| Type | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Molybdenum (Mo) | Nitrogen (N) | Phosphorus (P) | Sulfur (S) |
|---|---|---|---|---|---|---|---|
| 304 | ≤0.08% | 18.0-20.0% | 8.0-10.5% | – | – | ≤0.045% | ≤0.030% |
| 304L | ≤0.03% | 18.0-20.0% | 8.0-12.0% | – | – | ≤0.045% | ≤0.030% |
| 304N | ≤0.08% | 18.0-20.0% | 8.0-10.5% | – | 0.10-0.20% | ≤0.045% | ≤0.030% |
| 304H | 0.04-0.10% | 18.0-20.0% | 8.0-10.5% | – | – | ≤0.045% | ≤0.030% |
| 304F | ≤0.08% | 18.0-20.0% | 8.0-10.5% | – | – | ≤0.045% | ≤0.030% |
| 304D | ≤0.08% | 18.0-20.0% | 8.0-10.5% | – | Varies (if applicable) | ≤0.045% | ≤0.030% |
Mechanical Properties
| Property | 304 | 304L | 304N | 304H | 304F | 304D |
|---|---|---|---|---|---|---|
| Tensile Strength | ~520 MPa | ~520 MPa | ~600 MPa | ~515 MPa | ~520 MPa | ~520 MPa |
| Yield Strength | ~210 MPa | ~200 MPa | ~450 MPa | ~205 MPa | ~210 MPa | ~210 MPa |
| Elongation | ~40% | ~40% | ~40% | ~40% | ~40% | ~40% |
| Hardness | ~70 HRB | ~70 HRB | ~80 HRB | ~70 HRB | ~70 HRB | ~70 HRB |
| Impact Toughness | Good | Good | Excellent | Good | Good | Good |
| Modulus of Elasticity | ~193 GPa | ~193 GPa | ~193 GPa | ~193 GPa | ~193 GPa | ~193 GPa |
| Fatigue Strength | Moderate | Moderate | High | Moderate | Moderate | Moderate |