904L 30mm Super Duplex Stainless Steel Pipe 30 Inch For Petroleum ,
1,Application:Petroleum,chemical industry,electric power,boiler
904 l stainless steel pipe (00 cr20ni25mo4. 5 cu) has better
corrosion resistance of austenitic stainless steel.Because of
adding 1.5% copper,for reducing acid, such as sulfuric acid and
phosphoric acid also has very good corrosion resistance.In
addition, It has the characteristics of low carbon in welding
Corrosion resistance of 904 l stainless steel tube.
Since the 904 l carbon content is very low (the biggest is 0.020%),
so in the case of the general heat treatment and welding, there
would be no carbide precipitation.This eliminates the general heat
treatment after welding and appear in the danger of intergranular
corrosion.Because of the high nickel chrome molybdenum content, and
add the copper, so the 904 l stainless steel tube Even in a
reducing environment, such as sulfuric acid and formic acid can
also be in the passivation.High nickel content in the active state
has low corrosion rate.In the concentration range of 0 ~ 98% pure
sulfuric acid, the use of 904 l temperature can be as high as 40
℃.In 0 ~ 85% pure phosphoric acid concentration range, its
corrosion resistance is very good.In wet process of industrial
phosphoric acid, impurity against corrosion has a strong
influence.In all the various kinds of phosphate, 904 l stainless
steel tube corrosion resistance is superior to the ordinary
stainless steel pipe.In strong oxidizing nitrate, compared with the
high alloying steel does not contain molybdenum, low corrosion
resistance. In hydrochloric acid, the use of 904 l stainless steel
tube is limited to a lower concentration of 1-2%.In this
concentration range. Good corrosion resistance of 904 l stainless
steel tube to the conventional stainless steel.904 l stainless
steel tube have high corrosion resistance.The crevice corrosion
resistance in chloride solution is also very good.904 l stainless
steel pipe, high nickel content reduced in pit and the corrosion
rate of gaps.Ordinary austenitic stainless steel in the temperature
above 60 ℃, in a rich chloride environment sensitive to stress
corrosion may be, by improving the nickel content of stainless
steel, can reduce the sensitization.Because of the high content of
nickel, 904 l stainless steel tube in chloride solution,
concentration of hydroxide solution and rich hydrogen sulfide
environment, has the very high resistance to stress corrosion
•Processing plant for sulphuric, phosphoric and acetic acids
•Pulp and paper processing
•Components in gas scrubbing plants
•Seawater cooling equipment
•Oil refinery components
•Wires in electrostatic precipitators
Composition ranges for 904L grade of stainless steels.
Mechanical properties of 904L grade stainless steels.
Tensile Strength (MPa) min
Yield Strength 0.2% Proof (MPa) min
Elongation (% in 50mm) min
Rockwell B (HR B)
Rockwell Hardness value range is typical only; other values are
Typical physical properties for 904L grade stainless steels.
Mean Co-eff of Thermal Expansion (µm/m/°C)
Specific Heat 0-100°C
Grade Specification Comparison
Grade specifications for 904L grade stainless steels.
These comparisons are approximate only. The list is intended as a
comparison of functionally similar materials not as a schedule of
contractual equivalents. If exact equivalents are needed original
specifications must be consulted.
Good resistance to oxidation, but like other highly alloyed grades
suffers from structural instability (precipitation of brittle
phases such as sigma) at elevated temperatures. 904L should not be
used above about 400°C.
Solution Treatment (Annealing) - heat to 1090-1175°C and cool
rapidly. This grade cannot be hardened by thermal treatment.
904L can be successfully welded by all standard methods. Care needs
to be taken as this grade solidifies fully austenitic, so is
susceptible to hot cracking, particularly in constrained weldments.
No pre-heat should be used and in most cases post weld heat
treatment is also not required. AS 1554.6 pre-qualifies Grade 904L
rods and electrodes for welding of 904L.
904L is a high purity, low sulphur grade, and as such will not
machine well. Despite this the grade can be machined using standard
Bending to a small radius is readily carried out. In most cases
this is performed cold. Subsequent annealing is generally not
required, although it should be considered if the fabrication is to
be used in an environment where severe stress corrosion cracking
conditions are anticipated.
1,We have advanced NDT equipments for the tests such as Eddy
Current test, Ultrasonic test, Hydraulic test and so on.
2,We have ISO certificate, and the Third Party Inspection
Certificates such as TUV, BV, Lloyd’s, SGS, etc, also can be
provided according to customers’ requirements,
3,Wooden case package which is strong and suitable for sea
transportation is our main method to pack the pipes. And the
economical packing method such as packed in bundles is also
welcomed by some customers.
4,The tolerance control we use is +/-0.1mm on both inside and
outside Diameter and Wall Thickness, which is much higher than
international standard ASTM, DIN.
5,The surface condition is one of our main advantages: in order to
meet different requirements for surface condition, we have
annealing and pickling surface, bright annealing surface, OD
polished surface, OD & ID polished surface etc.
6,In order to keep the inside surface of pipe clean and make it
free from deburring, our company develops the unique and special
technology --- Sponge Washing with high pressure.
7,We have complete after-sale service to deal with the problems in