ISO/TR 15608 Material Group 7.1: Ferritic stainless steels with
C ≤ 0,35 % and 10,5 % ≤ Cr ≤ 30 %;
Features of Ferritic stainless steel
Ferritic stainless steel contains over 12% chromium with less than 0.20% carbon but with no, or very small addition of nickel. Molybdenum is added to some grades to improve the corrosion resistance, while alloying with niobium and/or titanium improves the weldability.
They are non-hardenable by heat treatment and only marginally hardenable by cold rolling. The bodycentred-cubic grain is responsible for ferritic steel’s magnetic nature, and in this it differs from all other types of stainless steel. While not as strong as martensitics, ferritics are highly corrosion resistant. Chromium rich ferritic stainless steels have good oxidation resistance at high temperatures and can be used to make furnace components.
The main disadvantages of the ferritics are:
- Limited toughness – Not acceptable low temperatures
- Formability – Good for deep drawing, but not stretch forming due to lower ductility
- Weldability – Rapid grain growth in thick sections, leads to poor weld toughness in comparison to the austenitics.
Ferritic stainless steels are weldable with conventional welding methods.
Typical materials in group 7.1
| Name | Number | Standard | Product | Remarks |
|---|---|---|---|---|
| 403 | S40300 | ASTM A-479 | Bar | ASME BPVC |
| 405 TP405 405 | S40500 S40500 S40500 | ASTM A-240 ASTM A-268 ASTM A-479 | Plate Smls. & welded tube Bar | ASME BPVC ASME BPVC ASME BPVC |
| S40800 | S40800 | ASTM A-268 | Smls. & welded tube | ASME BPVC |
| X2CrTi12 TP409 | 1.4512 S40900 | – ASTM A-268 | – Smls. & welded tube | – ASME BPVC |
| 409 | S40910 S40920 S40930 | ASTM A-240 ASTM A-240 ASTM A-240 | Plate Plate Plate | ASME BPVC ASME BPVC ASME BPVC |
| X6Cr17 F430 430 TP430 430 | 1.4016 S43000 S43000 S43000 S43000 | – ASTM A-182 ASTM A-240 ASTN A-268 ASTM A-479 | – Forging Plate Smls. & welded tube Bar | – ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| X3CrTi17 439 TP439 439 TP439 TP439 | 1.4510 S43035 S43035 S43035 S43035 S43035 | – ASTM A-240 ASTM A-268 ASTM A-479 ASTM A-731 ASTM A-803 | – Plate Smls. & welded tube Bar Smls. & welded pipe Smls. & welded pipe | – ASME BPVC ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| TP430Ti | S43036 | ASTM A-268 | Smls. & welded tube | ASME BPVC |
| X2CrTiNb18 S43932 | 1.4509 S43932 | – ASTM A-240 | – Plate | – ASME BPVC |
| S43940 | S43940 | ASTM A-240 | Plate | ASME BPVC |
| – | S44100 | ASTM A-240 | Plate | ASME BPVC |
| X2CrMoTi18-2 S44400 18Cr–2Mo S44400 18Cr–2Mo | 1.4521 S44400 S44400 S44400 S44400 | – ASTM A-240 ASTM A-268 ASTM A-479 ASTM A-731 | – Plate Smls. & welded tube Bars Smls. & welded pipe | – ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| TP446–1 TP446–2 | S44600 S44600 | ASTM A-268 ASTM A-268 | Smls. & welded tube Smls. & welded tube | ASME BPVC ASME BPVC |
| XM–33 TPXM–33 TPXM–33 | S44626 S44626 S44626 | ASTM A-240 ASTM A-268 ASTM A-731 | Plate Smls. & welded tube Smls. & welded pipe | ASME BPVC ASME BPVC ASME BPVC |
| FXM–27Cb XM–27 TPXM–27 XM–27 TPXM–27 | S44627 S44627 S44627 S44627 S44627 | ASTM A-182 ASTM A-240 ASTM A-268 ASTM A-479 ASTM A-731 | Forging Plate Smls. & welded tube Bar Smls. & welded pipe | ASME BPVC ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| S44635 25–4–4 | S44635 S44635 | ASTM A-240 ASTM A-268 | Plate Smls. & welded tube | ASME BPVC ASME BPVC |
| S44660 26–3–3 S44660 26–3–3 | S44660 S44660 S44660 S44660 | ASTM A-240 ASTM A-268 ASTM A-731 ASTM A-803 | Plate Smls. & welded tube Smls. & welded pipe Welded tube | ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| S44700 29–4 S44700 S44700 | S44700 S44700 S44700 S44700 | ASTM A-240 ASTM A-268 ASTM A-479 ASTM A-731 | Plate Smls. & welded tube Bars Smls. & welded pipe | ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| S44735 | S44735 | ASTM A-268 | Smls. & welded tube | ASME BPVC |
| S44800 29–4–2 S44800 S44800 | S44800 S44800 S44800 S44800 | ASTM A-240 ASTM A-268 ASTM A-479 ASTM A-731 | Plate Smls. & welded tube Bars Smls. & welded pipe | ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| X3CrNb17 | 1.4511 | EN 10088-2 | Plate | – |
| X2CrMoTi17-1 | 1.4513 | EN 10088-2 | Plate | – |
| X2CrMoNb18-2 | 1.4522 | EN 10088-2 | Plate | – |