Ferritic SS 444 Pipes and tubes
Ferritic SS 444 Pipe and SS 444 Tube are a low-carbon (C), low nitrogen (N), dual-stabilized
ferritic stainless steel. Among the 444 SS properties are pitting and crevice corrosion resistance
superior to most ferritic stainless steels and some austenitic stainless steels.
Chemical Composition
| GRADE | Cr | Ni | Mo | Fe | Si | C | Mn | |
|---|---|---|---|---|---|---|---|---|
| SS 444 | Min | – | – | – | – | – | – | |
| Max | 18.5 | 1 | 2 | 77.475 | 1 | 0.025 | 1 |
Specification
Stainless steel 444 Seamless Pipe : ASTM/ASME SA 312/ A 312
Stainless steel 444 Seamless tube : ASTM/ASME SA 213/A 213
Stainless steel 444 ERW Pipe : ASTM/ASME SA 312/ A 312
Stainless steel 444 ERW Tube : ASTM/ASME SA 249/ A 249
Specifications
| GRADE | UNS | EN | AFNOR | SWEDEN SS |
|---|---|---|---|---|
| SMO 254 | S31254 | 1.4521 | Z3CDT18-02 | 2326 |
Production Process
Grade SS 444 or UNS S4400 are manufactured through processes such as ERW (Electric
Resistance Welded), Seamless and EFW (Electric Fusion Welding). 444 stainless steel pipe and
444 stainless steel tube 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.
The process through which pipes and tubes can be manufactured include cold pilgering process,
Extrusion process, tube mill Process also Piercing process followed by heat treatment and
mechanical testing.
Fabrication and Heat Treatment
Stainless steel 444 pipe and stainless steel 444 tube can be normally annealed at 800°C for 90
minutes and followed by air quenching. For 444 fabrications, post-weld annealing might be
required. Stress-relieving if required, can be done at about 250°C.
Properties
SS grade 444 provides excellent formability and can be readily deep drawn and spin formed.
Stretch forming, however, is limited in application for this material.
Mechanical Properties
| Grade | Tensile Strength | Yield Strength | Elongation | Hardness,MAX | |
|---|---|---|---|---|---|
| [MPA] | [MPA] | (% in 50mm) min | HBW | HRB | |
| SS 444 | 415 | 275 | 20 | 95 | 217 |
SS 444 chemical composition provides it with excellent corrosion resistance in moderately
severe environments of many types that include chlorides and organic acids found in foods and
beverages.
Physical Properties
| Grade | Density (g/cm3) | Mean Co-eff of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat ( J/Kg.K) | Electrical Resistivity (μΩ.m) |
|---|---|---|---|---|---|
| SS 444 | 0-100°C | at 93°C | 0-100°C | at 21°C | |
| 7.82 | 11 | 26.8 | 427 | 57 |
