Overview
Grade 304 is the standard "18/8" stainless, it is the most versatile and most widely used stainless steel, available in a wider range of products, forms and finishes than any other. It has excellent forming and welding characteristics. ASTM A213 Seamless Tube mostly used as superheater, boiler, heat exchanger tubes. ASME SA213TP304 Tube made by an austenitic grade with the addition of 2% to 3% molybdenum which further improves corrosion resistance. ASTM A213 TP304 tubing sizes and thickness usually furnished to its specification are 1/8 inch (3.2 mm) in inside diameter to 5 inch (127 mm) in outside diameter and 0.015 to 0.500 inch (0.4 to 12.7 mm) inclusive, in minimum wall thickness. ASTM A213 UNS S30400 Tubing having other diameters may be furnished, provided such tubes comply with all other requirements of this specification.
Specification
A213/A213M-21b 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 | - | - |
| These comparisons are approximate only. The list is intended as a comparison of functionally similar materials not as a schedule of contractual equivalents. If exact equivalents are needed original specifications must be consulted. | |||||||
| Specification | ASTM A-213 & Its equivalent ASME, 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 (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| 304 | 515 | 205 | 40 | 92 | 201 |
| 304L | 485 | 170 | 40 | 92 | 201 |
| 304H | 515 | 205 | 40 | 92 | 201 |
| 304H also has a requirement for a grain size of ASTM No 7 or coarser. | |||||
Physical Properties
| Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100°C (J/kg.K) | Electrical Resistivity (nΩ.m) | |||
| 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
