First, 904L, sus890l type stainless steel: This is a combination of price and corrosion resistance of the cost-effective austenitic stainless steel, its corrosion resistance, especially suitable for the general sulfuric acid, phosphoric acid and other acids and halogenated (including cl-, f-). Because of the high content of CR, Ni and Mo, it has good resistance to stress corrosion, pitting and gap corrosion.
Applicable conditions in chlorine-containing media.
Second, 254 SMO advanced Stainless Steel: By increasing the MO content of the 316 type of improved ultra-low carbon advanced stainless steel, with excellent resistance to chloride pitting and gap corrosion performance, suitable for the use of 316 type of saline, inorganic acid and other media. Third, titanium: non-alloyed titanium, light weight, density of 4.51, can naturally produce passivation protective film (Ti2o3), and if destroyed, with "self-healing", so corrosion resistance than stainless steel, is suitable for chlorine containing medium (cl-concentration >200mg/l, temperature ≤130℃) typical materials. In seawater and other chloride (such as CACL2) solutions of no more than 120 ℃, they are not actually corroded.
In general, it can be used for seawater below 135 ℃ and for various concentrations of brine (NaCl) under 165 ℃.
Titanium in organic acids below the boiling point (such as concentrated nitric acid, concentrated carbonate, etc.) and dilute lye, corrosion resistance is also good. The corrosion resistance of titanium in H2SO4, HCl, HF and Wang Shui is poor. In the high temperature (more than 120 ℃) of certain concentrated chloride solution (such as PH>7, chloride concentration >200mg/l wastewater), may also cause gap corrosion or stress corrosion.
At this time, titanium-palladium alloys should be selected. Four, Hastelloy C-276: With good corrosion resistance: almost unaffected by cl-; excellent corrosion resistance to various concentrations of sulfuric acid, is one of the few materials that can be used for hot-concentrated sulfuric acid; widely used in organic acids (such as formic acid, acetic acid), high temperature HF acid and a certain concentration of hydrochloric acid (<40%), phosphoric acid ( ≤50%); chloride, fluoride and organic solvents (e.g. methanol, ethanol).
