304 and 303 are stainless steel, but the composition is different. SUS303 and SUS304 are Japanese terms, while China is called Y1Cr18Ni9 and 0Cr18Ni9 respectively. In China, they use international chemical element symbols and national symbols to express chemical composition, and Arabic letters to express the content of chemical composition. From the structural formula, we can see the difference between them. These two kinds of anticorrosive ability are very good, but 304 is better; the comparison of related materials shows that stainless steel can be coated with anticorrosive oil to achieve good anticorrosive effect in other cases when it rusts after 168 hours of salt spray test, but the effect is limited. It is inconvenient for production and installation, mainly depends on what effect you want to achieve, which material you choose, and the current comparison standard. Accurate sequence: common blue-white zinc-coated carbon steel < black zinc-coated carbon steel < galvanized nickel-coated carbon steel < stainless steel.
Difference
The main difference between low carbon steel and low carbon steel is that the carbon content is different.
The carbon content of sus303 is about < 0.15%.
The carbon content of SUS304 is about < 0.08%.
In fact, the sulfur content of SUS304 is much lower than that of sus303.
Sus 303:P < 0.20%, S < 0.15%.
Contrast
The method of steel number representation is roughly consistent with that of bonded steel number representation. Carbon content is expressed in terms of average carbon content.