Ferritic SS 430 Pipes and Tubes
430 stainless steel pipe (UNS S43000) is the most widely used family of Ferritic alloys. It is known for its good corrosion resistance to numerous substances, excellent stress, and formability, coupled with practical mechanical properties.
Chemical Composition
| GRADE | Ni | Cr | Si | C | Mn | P | S | Mo | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|
| SS 430 | Min | – | 16 | – | – | – | – | – | – | BALANCE |
| Max | 0.5 | 18 | 1 | 0.12 | 1 | 0.04 | 0.03 | – |
Specification
| GRADE | UNS | OLD BRITISH | EURONORM | SWEDISH SS | JAPANESE JIS | ||
|---|---|---|---|---|---|---|---|
| BS | EN | NO | NAME | ||||
| SS 430 | S43000 | 430S17 | 60 | 1.4016 | X8Cr17 | 2320 | SUS 430 |
Specification
Stainless steel 430 Seamless Pipe/Tube : ASTM/ASME SA 268/ A 268
Stainless steel 430 ERW Pipe/Tube : ASTM/ASME SA 268/ A 268
Production Process
Grade 430 or UNS S43000 are manufactured using processes such as ERW (Electric Resistance Welded), Seamless and EFW (Electric Fusion Welding). 430 stainless steel tube and pipe have different forms such as round, square, rectangle etc. having specific end as Plain End, Bevel End and Threaded End with nominal thickness of different schedule ranging from SCH 5 to SCH XXS.
Mechanical Properties
| Grade | Tensile Strength | Yield Strength | Elongation | Hardness,MAX | |
|---|---|---|---|---|---|
| [MPA] | [MPA] | (% in 50mm) min | HBW | HRB | |
| SS 430 | 450 | 205 | 22 | 89 | 183 |
The process through which SS 430 tube and SS 430 pipe can be manufactured include cold pilgering process, Extrusion process, tube mill Process also Piercing process followed by heat treatment and mechanical testing. These processes are mostly used by various 430 stainless steel pipe manufacturers.
Fabrication and Heat Treatment Process
430 treated steel can be hot worked in the temperature scope of 1500 to 1900° F. In 430 stainless steel grade solution annealing can be performed by heating grade 430 at a temperature range of 815 – 845°C (1499-1553°F).
Afterwards it has to be immediately slowly cooled down to 600°C (1112°F) and followed by air-cooling in a quick manner as slow cooling between 540 and 400°C (1004 and 752°F) tends to cause embrittlement.
Properties
SS430 has excellent corrosion resistance to a wide variety of corrosive media including nitric acid as well as sulphur gases and many organic and food acids. Being ferritic in nature, this alloy has very high resistance stress corrosion cracking.
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 (μΩ.m) | |||
|---|---|---|---|---|---|---|---|---|---|
| SS 430 | 0-100°C | 0-315°C | 0-538°C | at 100°C | at 500°C | 0-100°C | |||
| 7.8 | 200 | 10.4 | 11 | 11.4 | 26.1 | 26.3 | 460 | 600 | |
The 430 grade is a stainless steel best suited for mild corrosive environments. Without Molybdenum or Nickel additions, 430 stainless steel is significantly less expensive than 316.
This makes 430 stainless steel a good value choice for non-critical indoor environments. In elevated temperatures, 430 stainless steel offers good resistance to oxidation as well.
