304 stainless steel:
304 stainless steel has national standard, American standard, Japanese standard and European standard. First, the names are different, the national standard 06Cr19Ni10, the American standard ASTM304, the European standard 1.4301, and the Japanese standard SUS304. Second, the element content is slightly different. The national standard and Japanese standard chromium (Cr) content is between 18% and 20%, and the nickel (Ni) content is between 8% and 10.5%. The American and European standard chromium (Cr) content is between 18% and 20%. The content is between 17.5%-19.5%, and the nickel (Ni) content is between 8%-10.5%. The main difference is that the chromium (Cr) content requirements are different. The chromium (Cr) content of American standards and European standards only needs to reach more than 17.5% to meet the standards.
There is another grade of 304 stainless steel, S30408, which is the same as 304. The difference lies in the different production standards. S30408 is produced in accordance with the standards of GB-T 24511-2017 "Stainless steel and heat-resistant steel plates and strips for pressure equipment".
304L stainless steel:
The national standard of 304L stainless steel is S30403, which is the ultra-low carbon version of 304 stainless steel. The lower carbon content brings better corrosion resistance and welding performance. The carbon content of 304L stainless steel is reduced to less than 0.03%. On the basis of improving the corrosion resistance of stainless steel, it can also improve the sensitization caused by carbide precipitation and crystallization caused by welding between 450℃-860℃. Interval corrosion. The carbide precipitated by 304L stainless steel in the heat-affected zone close to the weld is reduced to a minimum, which improves the stainless steel's resistance to intergranular corrosion and extends the service life of the stainless steel welding contact. Moreover, the elongation performance of 304L stainless steel is better than that of 304 stainless steel, so it can be used instead of 304 in many cases. Of course, the price of 304L is also relatively high.
304N stainless steel:
The basic properties of 304N stainless steel are similar to 304 stainless steel, but 304N stainless steel is a stainless steel with nitrogen added. Nitrogen is added to improve the strength of stainless steel, so 304N stainless steel is generally used in places that require high cold formability.
304H stainless steel
304H stainless steel is the national standard S30409, which is the high-carbon version of 304, with better high temperature resistance and oxidation resistance. The H in 304H stainless steel refers to high temperature, and the high carbon content guarantees high-temperature strength. The carbon content of 304H stainless steel is not less than 0.04%.
304F stainless steel:
304F stainless steel and 304 stainless steel are similar. The difference lies in the sulfur content. The sulfur content of 304F stainless steel is 0.03%, and the sulfur content of 304 stainless steel is 0.001%. 304F stainless steel has better cutting performance than 304 stainless steel, but the sulfur content of 304F stainless steel The anti-rust ability is slightly worse than that of 304 stainless steel.
304D stainless steel:
First, the contents of chromium (Cr) and nickel (Ni) are different. 304D stainless steel contains 2.8% nickel (Ni), 18% chromium (Cr), and 7% manganese. 304D stainless steel is not a 304 stainless steel material. Second, the corrosion resistance is different. The corrosion resistance of 304D stainless steel is worse than that of 304 stainless steel. Third, the prices are different. 304D stainless steel is cheaper than 304 stainless steel.
