904 l N08904 1.4539 Super duplex stainless steel plate sheet
Description:
904L (N08904, 1.4539) super austenitic stainless steel contains
14.0-18.0% chromium, 24.0-26.0% nickel and 4.5% molybdenum.
904L super austenitic stainless steel is a kind of low carbon and
high nickel and molybdenum austenitic stainless steel with no rust
and acid resistance, which is a proprietary material imported from
French H·S company.
It has good activation-passivation conversion ability and excellent
corrosion resistance. It has good corrosion resistance in
non-oxidizing acids such as sulfuric acid, acetic acid, formic acid
and phosphoric acid, good pitting resistance in neutral chloride
ion medium, and good crevice corrosion resistance and stress
corrosion resistance.
Suitable for various concentrations of sulfuric acid below 70℃,
under normal pressure resistance to any concentration, any
temperature of acetic acid, and mixed acid formic acid and acetic
acid corrosion resistance is also very good.
Super austenitic stainless steel 904L (00cr20ni25mo4.5cu, N08904,
1.4539) is a kind of high-alloy austenitic stainless steel with low
carbon content and good corrosion resistance in dilute sulfuric
acid.
Has the high chromium content and plenty of nickel content, the
addition of copper makes it have strong ability to resist acid,
especially for chloride clearance corrosion and stress corrosion
cracking are highly resistant, not easy to appear, erosion and
fracture pitting resistance slightly better than other steel grade,
good machinability and weldability, can be used for pressure
vessels.
904 l N08904 1.4539 Chemical composition of stainless steel
C≤ | Si≤ | Mn≤ | P≤ | S≤ | Cr≥ | Ni≥ | Mo≥ | Cu≤ |
0.02 | 1.00 | 2.00 | 0.045 | 0.035 | 19.0-23.0 | 23.0-28.0 | 4.00-5.00 | 1.0-2.0 |
904L (N08904, 1.4539) super austenitic stainless steel
metallographic structure:
904L (N08904, 1.4539) super austenitic stainless steel is
completely austenitic structure, compared with the general
austenitic stainless steel with high molybdenum content, 904L is
not sensitive to the precipitation of ferrite and alpha phase.
904L (N08904, 1.4539) super austenitic stainless steel physical and
mechanical properties:
1. 904L (N08904, 1.4539) super austenitic stainless steel density:
8.24g/cm3.
2. 904L (N08904, 1.4539) super austenitic stainless steel tensile
strength: σb≥520Mpa.
3. 904L (N08904, 1.4539) super austenitic stainless steel yield
strength:σ0.2≥216Mpa
4, 904L (N08904, 1.4539) super austenitic stainless steel
elongation: δ≥35%.
Corrosion resistance of 904L (N08904, 1.4539) super austenitic
stainless steel:
Because 904L carbon content is very low (maximum 0.020%), there
will be no carbide precipitation in the case of general heat
treatment and welding.
This eliminates the risk of intergranular corrosion that usually
occurs after heat treatment and welding.
High chromium-nickel-molybdenum content and the addition of copper,
so 904L can be passivated even in reductive environments such as
sulfuric acid and formic acid.
The high nickel content makes it have lower corrosion rate in the
active state.
904L of pure sulfuric acid can be used at temperatures up to 40
degrees Celsius in concentrations ranging from 0 to 98%.
The corrosion resistance of pure phosphoric acid in the
concentration range of 0~85% is very good.
In industrial phosphoric acid produced by wet process, impurities
have a strong influence on corrosion resistance.
Among all kinds of phosphoric acid, 904L is more resistant to
corrosion than ordinary stainless steel.
In strong oxidizing nitric acid, 904L has lower corrosion
resistance than the high alloy steel without molybdenum.
In hydrochloric acid, the use of 904L is limited to lower
concentrations of 1-2%.
In this concentration range.
The corrosion resistance of 904L is better than that of
conventional stainless steel.
904L steel has high resistance to spot corrosion.
It is also very resistant to crevice corrosion in chloride
solution.
The high nickel content of 904L reduces the corrosion rate in pits
and crevices.
Normal austenitic stainless steels may be sensitive to stress
corrosion in a chlorine-rich environment at temperatures above 60
degrees Celsius. This sensitivity can be reduced by increasing the
nickel content of stainless steels.
Due to its high nickel content, 904L is highly resistant to stress
corrosion cracking in chloride solution, concentrated hydroxide
solution and hydrogen sulfide rich environment.
904L (N0804,,14539) super austenitic stainless steel processing
properties:
1. Welding performance: 904L (N08904, 1.4539) super austenitic
stainless steel can be welded in various ways.
The most commonly used welding method is manual arc welding or
inert gas shielded welding. The electrode or wire metal is based on
the composition of the parent metal and has higher purity, and the
requirement of molybdenum content is higher than that of the parent
metal.
Generally, there is no need to preheat before welding, but in cold
outdoor work, in order to avoid condensation of water vapor, joint
parts or adjacent areas can be heated evenly.
Note that the local temperature should not exceed 100 ℃, so as not
to lead to carbon accumulation and intercrystalline corrosion.
Small line energy, continuous and fast welding rate are used in
welding.
Generally, there is no need for heat treatment after welding. If
heat treatment is needed, it shall be heated to 110 0 ~ 1150℃ and
cooled down quickly.
2, machining performance: 904L (N08904, 1.4539) super austenitic
stainless steel machining characteristics similar to other
austenitic stainless steel, the process of sticking knife and work
hardening trend.
The cutting coolant should be vulcanized and chlorinated oil. The
equipment and process should be premised on reducing work
hardening.
Slow cutting speed and feed should be avoided during cutting.
904L (N0804,,14539) super austenitic stainless steel applications:
Petroleum and petrochemical equipment, such as reactors in
petrochemical equipment;
Storage and transportation equipment for sulfuric acid, such as
heat exchangers;
The main parts of flue gas desulfurization device in power plant
are: tower body, flue, door plate, inner part, spraying system,
etc.
Scrubber and fan in organic acid treatment system;
Sea water treatment equipment, sea water heat exchanger, paper
industry equipment, sulfuric acid, nitric acid equipment, acid,
pharmaceutical industry and other chemical equipment, pressure
vessels, food equipment;
Centrifuges, reactors, etc. in pharmaceutical factories;
Food machinery for soy sauce jars, cooking wine, salt jars,
equipment and dressings;
Equipment and components for strong corrosive medium of dilute
sulfuric acid.
Type specification and supply status of 904L (N0804,,14539) super
austenitic stainless steel:
1. Variety classification: 904L seamless pipe, 904L steel plate,
904L round steel, 904L forging, 904L flange, 904L ring, 904L welded
pipe, 904L steel belt, 904L wire material and 904L matching welding
material.
2, delivery status: seamless tube: solid solution + acid white,
length can be fixed length;
Plate: solid solution, pickling, cutting edge;
Welded pipe: solution acid white +RT% flaw detection, forging:
annealing + polishing;
Bar by forging rolling state, surface polishing or polishing;
After cold rolling, solid solution soft state, oxide skin delivery;
The silk material shall be delivered in the state of fine polishing
in the form of solid solution pickling tray or straight strip.