Overview
Bright annealing is the annealing of stainless steel sheet and strip continuously in a controlled-atmosphere furnace (depicted). The furnace atmosphere system includes an ammonia storage tank, a dissociator, and an adsorption dryer. Furnace capacity depends upon its specific size, source, temperature, and cooling rate, as well as the emissivity of the material processed. Atmosphere problems are purity and nitrogen pickup. Purity of the dissociated ammonia gas depends upon initial raw ammonia contaminants and dissociator performance. Nitrogen pickup can be prevented by annealing in purified hydrogen atmospheres. Production problems include atmosphere system leakage, maintenance of a temperature head, strip cleaning problems, and crystallized surface. Fabrication problems have included soldering and drawing. The advantages of bright annealed strip are improved surface finish, reduced buffing costs, and improved corrosion resistance.
Specification
ASTM A213/A213M-21a Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes.
Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
BS | En | No | Name | ||||
304 | S30400 | 304S31 | 58E | 1.4301 | X5CrNi18-10 | 2332 | SUS 304 |
304L | S30403 | 304S11 | - | 1.4306 | X2CrNi19-11 | 2352 | SUS 304L |
304H | S30409 | 304S51 | - | 1.4948 | X6CrNi18-11 | - | - |
Specification | ASTM A213 & ASME SA213, DIN & EN Standard. |
Grades | 304, 304H, 304L, 304LN. |
Type | Superheater, Seamless Ferritic and Austenitic Boiler and Heat-Exchanger Tubes |
Outer Diameter Size | 1/4” OD , NB to 3” OD , NB sizes |
Wall Thickness | 1mm to 12mm, SCH 5/5S, 40/40S, 10/10S, 20/20S, 80/80S, 120/120S, 160/160S as per ANSI B36.19/36.10 |
Ends | No.4 finish, No.1 Pickled Finish, BA Finish, Electropolished Seamless Tubes |
Other Testing | Product Analysis, Radiographic Examination, Transverse Tension Test, Flattening Test, Etching Test, Stabilizing Heat Treatment, Intergranular Corrosion Test, Grain Size Test, NACE 0175, Dual Grade, Weld Decay Test, Magnetic Particle Detection, PWHT (POST WELD HEAT TREATMENT), Flare Test, Bend Test, Hardness Test, Tensile Test etc |
Value Added Services | Draw / Expansion / Annealed / Heat Treatment / Machining / Sand Blasting / Shot Blasting / Bright Annealed |
Material Test Certificate | Manufacturer Test Certification As Per EN 10204 3.1, 3.2 / Laboratory Test Certificate From NABL Approved Lab. / Under Third Party Inspection Agency Like TUV, DNV, SGS, LLOYDS, ABS ETC |
Chemical Composition
Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | |
304 | min. | - | - | - | - | - | 18.0 | - | 8.0 | - |
max. | 0.08 | 2.0 | 0.75 | 0.045 | 0.030 | 20.0 | 10.5 | 0.10 | ||
304L | min. | - | - | - | - | - | 18.0 | - | 8.0 | - |
max. | 0.030 | 2.0 | 0.75 | 0.045 | 0.030 | 20.0 | 12.0 | 0.10 | ||
304H | min. | 0.04 | - | - | - | - | 18.0 | - | 8.0 | - |
max. | 0.10 | 2.0 | 0.75 | 0.045 | 0.030 | 20.0 | 10.5 | |||
Mechanical Properties
Grade | Tensile Strength | Yield Strength | Elongation | Hardness | |
Rockwell B | Brinell | ||||
304 | 515 | 205 | 40 | 92 | 201 |
304L | 485 | 170 | 40 | 92 | 201 |
304H | 515 | 205 | 40 | 92 | 201 |
Physical Properties
Grade | Density | Elastic Modulus | Mean Coefficient of | Thermal Conductivity | Specific Heat | Electrical Resistivity | |||
0-100°C | 0-315°C | 0-538°C | at 100°C | at 500°C | |||||
304/L/H | 8000 | 193 | 17.2 | 17.8 | 18.4 | 16.2 | 21.5 | 500 | 720 |
Applications
1. Oil and gas equipments
2. Offshore technology
3. Seawater desalination plants
4. Chemical industry
5. Bridges
6. Storage tanks
7. Medical Industry
8. Civil Engineering
9. Pressure vessels, reactor tanks, and heat exchangers
10. Rotors, impellers and shafts
11. Power plants
12. Petrochemical
13. Shipbuilding industry
