Heat-resistant Cr-Mo steels
FERVEO CMO 91 TIG
TIG rodCatalogue only
AWS class
ER90S-B9
EN ISO class
G CrMo 91
Tensile strength (Rm)
720 MPa
Classification
| AWS class | ER90S-B9 |
|---|---|
| EN ISO class | G CrMo 91 |
Purpose
- High-alloy solid TIG rod, P91 grade (9% Cr–1% Mo–V–Nb, AWS ER90S-B9, EN ISO G CrMo 91) — welding and surfacing of quenched-and-tempered 9% Cr steels like T91/P91, resistant to hot scaling up to 600°C.
Why it works
Vanadium and niobium give the P91 grade much higher creep strength than a conventional 9Cr-1Mo — the same alloying principle as the FERVEO CMO 91B HD P2/91B HD P2 15 electrodes, here in solid-rod form for TIG.
Fields of application
- Joining and surfacing of quenched-and-tempered P91/T91 (9% Cr) steel in supercritical-cycle plants.
Chemical composition
| Element | Typical, % |
|---|---|
| C | 0.09 |
| N | 0.05 |
| V | 0.2 |
| Cr | 9 |
| Mn | 0.6 |
| Mo | 0.95 |
| Nb | 0.06 |
| Ni | 0.65 |
| Si | 0.25 |
Mechanical properties
| Tensile strength (Rm) | 720 MPa |
|---|---|
| Yield strength (Rp0.2) | 630 MPa |
| Elongation (A5) | 18 % |
| Impact energy (KV) | 60 J |
Process
| Polarity | DC− |
|---|---|
| Shielding gas | I1 |
Sizes and part numbers
| Ø | Request |
|---|---|
| 1 mm | |
| 1.6 mm | |
| 2.4 mm | |
| 3.2 mm |
Supply programme
boxes 25 kg
Cross-reference
| Replaces TG 295 (Magmaweld) | Requires WPS validation |
| Replaces TIGAS TIG CrMo91 (Askaynak) | Requires WPS validation |
Equivalence refers to the classification (AWS / EN ISO), not to product identity. In applications with a qualified procedure (WPS), validate the substitution before use.
Base metals
T91P91
Advantages
- Solid-rod format — mechanized/semi-automatic welding productivity and lower starting hydrogen than a covered electrode.
- Same P91 alloy grade as the FERVEO CMO 91B HD P2/91B HD P2 15 electrodes — consistent in-service behavior across processes.
Limitations
- Like the family's P91 electrodes, requires preheat and interpass control due to its high hardenability.