Alloy 904L is a high-combination austenitic stainless steel with low carbon content. The evaluation is
proposed for utilization under extreme destructive conditions. It has been application demonstrated over
numerous years and was initially created to oppose consumption in weaken sulphuric corrosive. It is
institutionalized and affirmed for weight vessel use in a few nations. Basically, Alloy 904L is completely
austenitic and is less delicate to precipitation ferrite and sigma stages than customary austenitic
evaluations with high molybdenum content. Distinctively, because of the mix of generally high substance of
chromium, nickel, molybdenum and copper 904L has great imperviousness to general erosion, especially in
sulphuric and phosphoric conditions.
SPECIFICATIONS:
- ASTM B677, B366
- ASME SB677, SB366
FEATURES OF ALLOY 904L
- Profoundly impervious to setting, hole and general erosion.
- High imperviousness to chloride stress erosion breaking
- 50% stronger than 300-arrangement austenitic stainless steels
- Superb effect sturdiness
- Superb workability and weldability
USES OF ALLOY 904L
- Seawater taking care of gear
- Mash factory dye frameworks
- Compound transforming hardware
- Sustenance transforming hardware
- Desalination hardware
- Vent gas desulphurization scrubbers
Introduction
Grade 904L stainless steel is a non-stabilized austenitic stainless steel with low carbon content. This
high alloy stainless steel is added with copper to improve its resistance to strong reducing acids, such as
sulphuric acid. The steel is also resistant to stress corrosion cracking and crevice corrosion. Grade 904L
is non-magnetic, and offers excellent formability, toughness and weldability.
Grade 904L contains high amounts of expensive ingredients, such as molybdenum and nickel. Today, most of the
applications that employ grade 904L are replaced by low-cost duplex stainless steel 2205.
Chemical Formula
Fe, <0.02% C, 19-23% Cr, 23-28% Ni, 4-5% Mo, <2.0% Mn, <1.0% Si, <0.045% P, <0.035% S,
1.0-2.0% Cu
Key Properties
The following sections describe the properties of flat rolled products in ASTM B625. The specifications may
not be identical for other products such as bar, tube and pipe.
Mechanical Properties
The typical mechanical properties of grade 904L stainless steels are given in the table below:
|
Grade
|
Tensile Strength (MPa) min
|
Yield Strength 0.2% Proof (MPa) min
|
Elongation (% in 50mm) min
|
Hardness
|
| |
|
|
|
Rockwell B (HR B)
|
Brinell (HB)
|
|
904L
|
490
|
220
|
36
|
70-90 typical
|
150
|
Composition
The table below provides the compositional ranges of grade 904L stainless steels:
|
Grade
|
C
|
Mn
|
Si
|
P
|
S
|
Cr
|
Mo
|
NI
|
Cu
|
|
904L
|
min.
|
-
|
-
|
-
|
-
|
-
|
19
|
4
|
23
|
1
|
|
max.
|
0.02
|
2
|
1
|
0.045
|
0.035
|
23
|
5
|
28
|
2
|
Grade Specification Comparison
The following table outlines the approximate grade comparisons of 904L stainless steels:
|
Grade
|
No one
|
Old British
|
Euronorm
|
Swedish SS
|
Japanese JIS
|
|
|
|
BS
|
In
|
No
|
Name
|
|
|
|
904L
|
N08904
|
904S13
|
-
|
1.4539
|
X1NiCrMoCuN25-20-5
|
2562
|
-
|
Corrosion Resistance
Grade 904L stainless steels have excellent resistance to warm seawater and chloride attack. The high
resistance of grade 904L against stress corrosion cracking is due to the presence of high amounts of nickel
in its composition. Moreover, the addition of copper to these grades develops resistance to sulphuric acid
and other reducing agents in both aggressive and mild conditions.
The corrosion resistance of grade 904L is intermediate between super austenitic grades, with 6% molybdenum
content, and standard 316L austenitic grades. Grade 904L is less resistant to nitric acid than grades 304L
and 310L, which are free of molybdenum. This steel grade needs to be solution treated following cold
working, to achieve maximum stress corrosion cracking resistance under critical environments.
Welding
Welding of grade 904L stainless steels can be performed using all conventional methods. This grade does not
require pre-heat and post-weld heat treatments. Grade 904L can be subjected to hot cracking in constrained
weldment. Grade 904L electrodes and rods are used for welding grade 904L steels according to AS 1554.6.
Fabrication
Grade 904L stainless steels are high purity steels with low sulphur content. They can be machined using any
standard methods. These grades can be readily bent to a small radius under cold conditions. Although
subsequent annealing is not required in most cases, it should be carried out when the fabrication is
performed under severe stress corrosion cracking conditions.
Applications
Some of the major applications of grade 904L stainless steels include:
- Wiring in electrostatic precipitators
- Oil refinery components
- Seawater cooling devices
- Scrubbing plants
- Paper processing industries
- Acetic, phosphoric and sulphuric acid processing plants
Product Range
Below are listed Alloy 904L products in all Grades
- Stainless Steel 904L Plate/Plates
- Stainless Steel 904L Coil/Coils
- Stainless Steel 904L Sheet/Sheets
- Stainless Steel 904L Flat/Flats
- Stainless Steel 904L Pipe/Pipes
- Stainless Steel 904L Seamless Pipe/Pipes
- Stainless Steel 904L ERW Pipe/Pipes
- Stainless Steel 904L Welded Pipe/Pipes
- Stainless Steel 904L Butt-weld Fittings
- Stainless Steel 904L Socket-weld Fittings
- Stainless Steel 904L Flanges
- Stainless Steel 904L Elbow
- Stainless Steel 904L Reducer
- Stainless Steel 904L Tee
|
- Stainless Steel 904L Stub-end
- Stainless Steel 904L Concentric Reducer
- Stainless Steel 904L Eccentric Reducer
- Stainless Steel 904L Forged Fittings
- Stainless Steel 904L Round Bar
- Stainless Steel 904L Hollow Section
- Stainless Steel 904L Angle/Angles
- Stainless Steel 904L Channel/Channels
- Stainless Steel 904L Beam/Beams
- Stainless Steel 904L Fasteners
- Stainless Steel 904L Blind Flanges
- Stainless Steel 904L Slip-on Flanges
- Stainless Steel 904L Weld neck Flanges
- Stainless Steel 904L Seamless Fittings
|