Austenitic SS 304 Round Bar
SS 304 is austenitic stainless steel also known as 18/8 stainless steel because of its chemical composition. SS 304 round bar due to its austenitic structure is ductile in nature. 304 round bar also has excellent low temperature properties and responds well to hardening by cold working. If intergranular corrosion in the heat affected zone may occur, it is suggested that SS 304L be used.
Chemical Composition
|
GRADE |
NI |
CR |
Si |
C |
MN |
P |
S |
N |
Fe |
|
|---|---|---|---|---|---|---|---|---|---|---|
|
SS 304 |
MIN % |
8 |
18 |
– |
– |
– |
– |
BALANCE |
||
|
MAX % |
13 |
20 |
0.75 |
0.08 |
2 |
0.045 |
0.03 |
0.1 |
||
|
SS 304H |
MIN % |
8 |
18 |
– |
– |
– |
– |
BALANCE |
||
|
MAX % |
12 |
20 |
0.75 |
0.03 |
2 |
0.045 |
0.03 |
0.1 |
||
|
SS 304L |
MIN % |
8 |
18 |
– |
0.04 |
– |
BALANCE |
|||
|
MAX % |
10.5 |
20 |
0.75 |
0.1 |
2 |
0.045 |
0.03 |
Properties
304 stainless round bar has good resistance to oxidation in intermittent service up to 870°C and in continuous service to 925°C. However, continuous use at 425-860°C is not recommended if corrosion resistance in water is required. In this instance 304L is recommended due to its resistance to carbide precipitation.
Mechanical Properties
|
Grade |
Tensile Strength |
Yield Strength |
Elongation |
Reduction of area |
|---|---|---|---|---|
|
[MPA] |
[MPA] |
(% in 50mm) min |
min % |
|
|
SS 304 |
515 |
205 |
40 |
50 |
|
SS 304H |
515 |
205 |
40 |
50 |
|
SS 304L |
485 |
170 |
40 |
50 |
Where high strength is required at temperatures above 500°C and up to 800°C, grade 304H is recommended. This material will retain aqueous corrosion resistance.
Physical Properties
|
Grade |
Density (g/cm3) |
Elastic Modulus (GPa) |
Mean Co-eff of Thermal Expansion (μm/m/°C) |
Thermal Conductivity (W/m.K) |
Specific Heat (J/Kg.K) |
Electrical Resistivity (nΩ.m) |
|||
|---|---|---|---|---|---|---|---|---|---|
|
0-100°C |
0-100°C |
0-315°C |
0-538°C |
at 100°C |
at 500°C |
||||
|
SS 304/H/L |
8 |
193 |
17.2 |
17.8 |
18.4 |
16.2 |
21.5 |
500 |
720 |
304 stainless steel round bar is less electrically and conductive than carbon steel and is essentially non-magnetic. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes.
Specification
The Specification for Wrought Stainless steel Bars as per astm Standard is ASTM A276/ASME SA-276, they are categorised into different form and shape such as SS 304/L/H Round Bar, Rod, Channel Bar, T-Bar, Flat Bar, Blocks, Square, bar, Triangle, Threaded, Hex (A/F), Profiles, Half Ingot, Billet, I/H Bar, etc. and are available at major SS 304 round bar suppliers.
When considering wrought stainless 304 round bar, material shall be furnished in the following way such as Hot-worked, Hot-worked and Annealed, Hot-worked- Annealed and cold worked or Hot-worked-Annealed and heat treated.
Round bars depending upon their treatment and their use and application they can also be available in different surface finishes such as Black, Bright Polished, Rough Turned, NO.4 Finish, Matt Finish, BA Finish, 2B, 2D, etc.
Applications
- Off-Shore Oil Drilling Companies
- Power Generation
- Petrochemicals
- Gas Processing
- Specialty Chemicals
- Pharmaceuticals
- Pharmaceutical Equipment
- Chemical Equipment
- Sea Water Equipment
- Heat Exchangers
- Condensers
- Pulp and Paper Industry
