Stainless Steel 904L Technical Specification By yaang.com

Stainless Steel 904L is a non-stabilised low carbon high alloy austenitic stainless steel. The addition of copper to this grade gives it greatly improved resistance to strong reducing acids, particularly sulphuric acid. It is also highly resistant to chloride attack - both pitting crevice corrosion and stress corrosion cracking. This grade is non-magnetic in all conditions and has excellent weldability and formability. The austenitic structure also gives this grade excellent toughness, even down to cryogenic temperatures. Stainless Steel 904L does have very substantial contents of the high cost ingredients nickel and molybdenum. Many of the applications in which this grade has previously performed well can now be fulfilled at lower cost by duplex stainless steel 2205 (S31803 or S32205), so it is used less commonly than in the past.

Chemical composition
(average %)

C	Si	Mn	Cr	Mo	Ni	Cu	N
0,020	0,50	0,75	20,30	4,50	25,10	1,50	0,06

Standards

DIN	AFNOR	UNS	SIS
1.4539 X1NiCrMoCu25-20-5	Z2NCDU25-20	N08904	2562

Mechanical properties at room temperature
Condition: solution quenched

Product	Dimensions	0.2% proof stress	1% proof stress	Tensile strenght	Elongation A5			Impact strenght (ISO-V)
	mm	N/mm² min	N/mm² min	N/mm²	L	Q	T	L	Q	T
BI	< 30				—	35	—	—	55	—
St.Sch	< 160	220	250	520-720	40	—	—	85	—	—

St = Bars Sch = Forgings BI = Sheet or Plate L = Longitudinal Q = Transverse T = Tangential

The values for others products and dimensions shall be establishedin accordance with relevant specifications by agreement.

High - Temperature properties

Temperature	50°C	100°C	150°C	200°C	250°C	300°C	350°C	400 °C
0.2% proof stress N/mm² min	190	175	165	155	145	135	130	125
1% proof stress N/mm² min	220	205	195	185	175	165	160	155

Physical properties

Density at	20°C	8.00 g/dm
Thermal conductivity at	20°C	12 W/(mK)
Specific heat at	20°C	0.45 J/(gK)
Electric resistivity at	20°C	1.00 Ohm mm/m
Modulus of elasticity at	20°C	197 x 10 N/mm
Magnetic properties	Can be slightly magnetic

Thermal expansion between 20°C e ...°C 10 m/(mK)	Temperature	10 m/(mK)
	100°C	15.8
	200°C	16.1
	300°C	16.5
	400°C	16.9
	500°C	17.3

Modulus of elasticity, 10 N/mm at	Temperature	10 N/mm
	20°C	197
	100°C	191
	200°C	184
	300°C	177
	400°C	170
	500°C	163

Corrosion Resistance
Although originally developed for its resistance to sulphuric acid it also has a very high resistance to a wide range of
environments. A PRE of 35 indicates that the material has good resistance to warm sea water and other high chloride
environments. High nickel content results in a much better resistance to stress corrosion cracking than the standard austenitic grades. Copper adds resistance to sulphuric and other reducing acids, particularly in the very aggressive "mid concentration" range.
In most environments Stainless Steel 904L has a corrosion performance intermediate between the standard austenitic grade 316L and the very highly alloyed 6% molybdenum and similar "super austenitic" grades.
In aggressive nitric acid Stainless Steel 904L has less resistance than molybdenum-free grades such as Stainless Steel 904LL andStainless Steel 310L.
For maximum stress corrosion cracking resistance in critical environments the steel should be solution treated after cold work.
Heat Resistance
Good resistance to oxidation, but like other highly alloyed grades suffers from structural instability (precipitation of brittle
phases such as sigma) at elevated temperatures. Stainless Steel 904L should not be used above about 400C.
Heat Treatment

Solution Treatment (Annealing) - heat to 1090-1175C and cool rapidly. This grade cannot be hardened by thermal treatment. 

Welding

Stainless Steel 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.
Fabrication
Stainless Steel 904L is a high purity, low sulphur grade, and as such will not machine well. Despite this the grade can be machined using
standard techniques.
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.

APPLICATIONS FIELD :

Industry	Applications	Industry	Applications
Chemical	Heat Exchanger,Boiler	Sugar	Evaporators, Condensers, Driers
Petrochemicals	Condensers	Automobiles	Muffler Tubes Hydraulic Tubing
Refineries	General Piping	Construction	Architectural Furniture
Fertilizers	Pressure Vessels	Pharmaceuticals, Dairy, Food & Beverages	Machineries Process Piping, Stainless Steel U Tubes
Paper & Pulp	Industrial Equipments	Submersible Pumps	Pump Casing Applications
Engineering	Machineries Instrumentation Tubing	Oil and Gas	Stainless Steel pipes, Stainless Steel Pipe Fittings, Stainless Steel Flanges

Yaang Pipe Industry Co., Limited offers a comprehensive range of 904L Stainless Steel Pipes and 904L Stainless Steel Tubes.

904L Stainless Steel Pipes and 904L Stainless Steel Tubes Product Range
904L Stainless Steel Pipes and 904L Stainless Steel Tubes Specifications: ASTM A/ASME SA 269/677 904L Stainless Steel Pipes and 904L Stainless Steel Tubes Sizes
(Seamless): 1/2" NB - 8" NB
904L Stainless Steel Pipes and 904L Stainless Steel Tubes Sizes (ERW): 1/2" NB - 24" NB
904L Stainless Steel Pipes and 904L Stainless Steel Tubes Sizes (EFW): 6" NB - 100" NB

904L Stainless Steel Pipes and 904L Stainless Steel Tubes Wall Thickness available:
Schedule 5S - Schedule XXS (heavier on request)
904L Stainless Steel Pipes and 904L Stainless Steel Tubes Other Materials Testing:
NACE MR0175, H2 SERVICE, OXYGEN SERVICE, CRYO SERVICE, etc

These properties are specified for flat rolled product (plate, sheet and coil) in ASTM B625. Similar but not necessarily identical properties are specified for other products such as pipe, tube and bar in their respective specifications.

Source: Yaang Pipe Industry Co., Limited (www.yaang.com)

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