Passivation of 304 and 316 stainless steels in various acid solutions was studied as a function of exposure time and acid concentration. Nitric acid, citric acid, and the commercial Citrisurf (a 304, 304L versus 316 in corrosion resistance against Nov 24, 2004 · Nitric Acid is a specific environment for intergranular attack (IGA) on sensitized austenitic grades. As such the low carbon and stabilized grades are used i.e.,304L ( instead of 304), 321 and 347. A nitric acid grade (NAG) of very low carbon, silicon and phosphorus to improve resistance to IGA is
304 304L 305 308 309 309s 310 310s 314 316 316L 317 D319 321 347 348 384 385 Classification of Chromium-Nickel Stainless Steel Castings 0.15 0.15 0.15 0.15 0.15 0.15 0.15 .08 .03 0.12 .08 0.20 .08 0.25 .08 0.25 .08 .03 .08 .07 .08 .08 .08 Nitric Acid Nitric Acid Nitric Acid Nitric Acid & Hydrofluoric Acid Oxalic Acid Corrosion assessment of type 304L stainless steel in AISI type 304L stainless steel (SS) was assessed for its corrosion resistance in nitric acid solution. The effect of variation in nitric acid concentration (I to]ON) and temperature (298 K, 313 K Passivating 304 Stainless? - Practical MachinistDec 16, 2019 · I asked him what they used and he said nitric acid. I asked him about citric acid passivation and he said he tried it but didn't think think it did much so they continued with nitric acid passivation. Also, we had issues with 304/316 stainless in an environment with chlorine.
Jan 25, 2019 · Chemical removal by pickling is often a better option. Pickling uses a mixture of nitric and hydrofluoric (HF) acids. The wide range of concentrations and exposure times are described in ASTM A380 Standard Practice for Cleaning, Descaling and Passivation of Stainless Steel STAINLESS STEEL Grade 304, 304L, 304H304 SS has excellent corrosion resistance in a wide variety of corrosive media, including foodstus, sterilizing solutions, most organic chemicals and dyes and a wide variety of inorganic chemicals. Iso-corrosion diagrams for 304 in sulfuric, nitric, hydrochloric, phosphoric and acetic acids are shown below. SULPHURIC ACID % Acid by Weight Selection of stainless steels for handling nitric acid This shows that the 304 types can be used over a wide range of concentration and temperature, up to 95%, for storage applications. The 304 types are preferable to 316 types for nitric acid applications however. This is an exception to the general rule for stainless steels where the 316 types are normally found to be more corrosion resistant than 304 types. Over 95% concentration, aluminium alloys should be considered OR 4% silicon stainless steels.
304 Stainless Steel:Contains 18% chromium and 8% nickel; More of an economic choice if high concentrations of chloride arent present. 316 Stainless Steel:Contains 16% chromium, 10% nickel and an additional 2% molybdenum; The added molybdenum provides greater corrosion resistance to acids and localized pitting attack by chloride solutions such as sea water and de-icing salts.Corrosion studies of stainless steel 304 L in nitric acid Feb 21, 2020 · In order to better understand the role of uranium on the corrosion behavior of stainless in aqueous nuclear fuel reprocessing and decontamination operations, 304L stainless steel coupons were treated with nitric acid media at 45 °C and 90 °C in the presence of 0.3 M of uranyl nitrate. The impact of time, temperature, nitric acid concentration and uranyl nitrate concentration has been studied over a