Stainless Steel – Grade 904L (UNS N08904) Chemical formula Fe, <of 0.02% C, 19-23 percent chromium, 23-28 percent Ni, 4-5% Mo, <2.0% Mn, <1.0 percent si, <0.045% P <0.035% S, 1.0-2.0 percent Cu
904L is a good carbon high alloy austenitic stainless steel is not stable. The addition of copper to the distribution layer to mention it improves resistance to acids significantly reduced, typically sulfuric acid. It is also resistant to chloride attack – both 2 pitting / crevice corrosion and stress corrosion cracking.
This layer is non-magnetic in all conditions and possesses excellent weldability and formability. Austenitic structure also provides excellent durability for this class, even down to freezing temperatures.
904L no content are crucial components of the high price of nickel and molybdenum. of these widely applicable, the slow implementation of this class has done before slow deployment can be practiced also carry ownership more affordable price duplex stainless steel 2205 (S31803 or S32205), which in turn consumers are less popular than before.
Important attributes of stainless steel coil 904
these properties are specified for flat rolled products (plate, sheet and coil) in ASTM B625. Such attributes but not exactly the same one ink must be specified for other products such as shaft pipe, tube and bar in the corresponding scientific parameters.
although growth was initially resistant to sulfuric acid it also possesses very high resistance 1 property 1 series environments. a PRE of 35 indicates that the material possesses low resistance to make warm sea water and other high chloride environments. High nickel content results in a more reasonable resistance to stress corrosion cracking than the standard austenitic grades. Dong added sulfuric acid resistance and bring another reduction, characterized by very active in “mid concentration” range.
In most environments 904L stainless steel with a corrosion performance intermediate between the standard austenitic grade 316L and the alloys are very high 6% molybdenum and so as “super austenitic” grades.
In nitric acid 904L energetically carry less resistance than grade molybdenum – 304L and 310L free like.
low resistance to oxidation, but like other high grade alloys lose structural stability (precipitation of brittle phases such as sigma) at high temperatures. 904L should not be used above 400 ° C.
Measures of treatment (annealing) – from 1090 to 1175 ° C heat and cool quickly. This grade can not be hardened by heat treatment.
904L can be welded successfully brought many standard ways. care should be taken as this grade austenitic fully consolidated, the same is susceptible to cracking hot, unique in restricted common weldments. Heat does not own the money should be used widely and in the case of weld heat treatment is not essential post. AS 1554.6 pre qualified class bar 904L and 904L welding electrodes.
904L is a high purity, low sulfur grade, and as such will not machine well. Even though the property classes can be processed using standard technology standards.
Small bending radius is to facilitate implementation. In many cases this is done cold. Incubate next usually do not need to have, although it should be regarded as consideration for fabrication is used in an environment where the conditions of stress corrosion cracking is forecasting dangerous.
application of stainless steel 904
Typical application include:
• Processing plant for sulfuric, phosphoric and acetic acid
• pulp and paper processing
• Plant the rub ingredients in air
• cool widgets makes sea
• the composition Refinery
• Wires in electrostatic