Material of the flue gas inlet pipeline of the catalytic unit

The main difference between 304 and 316 is that 316 contains 2-3 more percent of nickel compared to 304, as well as 2% more molybdenum. Firstly, 316 stainless steel contains molybdenum, which gives it better corrosion resistance in high-temperature environments; therefore, engineers generally choose components made of 316 material in such conditions. Secondly, 316 mainly reduces the Cr content, increases the Ni content, and adds 2%–3% Mo. As a result, its corrosion resistance is greater than that of 304, making it suitable for use in chemical and seawater environments. Similarly, the cost of 316 is higher than that of 304; 316 is generally used in applications with higher requirements as a substitute for 304. The corrosion resistance of stainless steel decreases as the carbon content increases; therefore, the carbon content in most stainless steels is low, not exceeding 1.2%. In some steels, the Wc (carbon content) is even lower than 0.03% (such as 00Cr12). The main alloying element in stainless steel is Cr (chromium); only when the Cr content reaches a certain level does the steel possess corrosion resistance. Therefore, stainless steel generally has a Cr (chromium) content of at least 10.5%. Stainless steel also contains elements such as Ni, Ti, Mn, N, Nb, Mo, Si, and Cu.

316H is mainly resistant to high temperatures, while 316L is mainly resistant to corrosion