Corrosion resistance of 904L stainless steel
It is acknowledged that the carbon content of 904L stainless steel is very low. It is no more than 0.020 percent. So there is no precipitation of carbides under the circumstances of general heat treatment and welding, which avoids the risk of intergranular corrosion appearing after the general heat treatment and welding. Due to the high content of chromium-nickel-molybdenum, and adding copper, 904L may be passivated even though it is in reductive environment, such as sulfuric acid and formic acid. High nickel content makes the speed of corrosion resistance very slow in the active state. The temperature of 904 can be up to 40℃ when it is put in the pure sulfuric acid of which the range of concentration is 0 to 98 percent. Its corrosion resistant is reletively good if put in the pure phosphoric acid of which the range of concentration is 0 to 85 percent. The impurities have a strong influence on corrosion resistance when it is in the production of industrial phosphoric acid by the wet process. In all kinds of phosphoric acid, the corrosion resistance of 904L stainless steel is much superiorer than ordinary stainless steels. However, in strong oxidizing nitric acid, the corrosion resistance of 904L isn't that good when compared with the high-alloy steels without molybdenum. In hydrochloric acid, 904L can be only used in the lower concentration of 1 to 2%. The corrosion resistance of 904L stainless steel is better than other ordinary steels within this range. The obvious advantage of 904L stainless steel is that its pitting-corrosion resistance is perfectly good. More over, its crevice corrosion resistance is also quite good in chloride solution. The high content of nickel has reduced the corrosion rate in the pits and crevices.
These are the physical and mechanical performances of 904L stainless steel. Hope it is a good chance for you to get to know about it.- 【Hits:】 【Add:2013-04-10】 【Close】
