Heat-resistant Cr-Mo steels
FERVEO CMO 91
covered electrode · stick electrodeCatalogue only
also as: solid wireTIG rod
AWS class
E 9018-B92 (mod.) C
EN ISO class
---
Tensile strength (Rm)
650 MPa
Classification
| AWS class | E 9018-B92 (mod.) C |
|---|---|
| EN ISO class | --- |
Purpose
- Ultra-high-alloy basic electrode, P92 grade (9% Cr–0.5% Mo–1.8% W–V, AWS E9018-B92 mod.) — despite its name, the chemistry corresponds to the T/P92 grade, the top step of the FERVEO CMO family, for ultra-supercritical-cycle plants.
Why it works
Tungsten (1.8%) added to the 9Cr-Mo-V base of the P91 grade further raises creep strength at very high temperature — the reason the P92 grade replaces P91 in the most demanding ultra-supercritical-cycle plants, though it demands the same preheat and interpass care due to its high hardenability.
Fields of application
- Ultra-supercritical-cycle power-plant boilers and piping in P92 (T92) steel.
Chemical composition
| Element | Typical, % |
|---|---|
| V | 0.2 |
| W | 1.8 |
| Cr | 8.5 |
| Mn | 0.65 |
| Mo | 0.5 |
| Ni | 0.75 |
| Si | 0.25 |
Mechanical properties
| Tensile strength (Rm) | 650 MPa |
|---|---|
| Yield strength (Rp0.2) | 550 MPa |
| Elongation (A5) | 19 % |
| Impact energy (KV) | 47 J (20 °C) |
Process
| Polarity | DC+ |
|---|---|
| Positions | PAflatPBhorizontal-verticalPChorizontalPDhorizontal-overheadPEoverheadPFvertical-upPGvertical-down |
| Re-drying | 300–350 °C / ≥2 h |
| Heat treatment | 745-775°C / 4h / |
Sizes and part numbers
| Ø | Length | Current | Request |
|---|---|---|---|
| 3.2 mm | 350 mm | 110–140 A |
Base metals
T/P929%Cr1.7%W0.5%Mocreep resisting martensitic steels:ASTM: A213 Gr T92A 335 Gr P92A387 Gr 92Current TypeD.C.(+)
Advantages
- Higher creep strength than even the FERVEO CMO 91B HD P2 family (P91 grade), thanks to tungsten — the top step of the entire FERVEO CMO family.
- Also covers the vertical-down position.
Limitations
- Its commercial name ("91") doesn't match its actual classification (P92, not P91) — verify the exact AWS/EN ISO classification against the qualified WPS before substituting it for a P91 product.
- High hardenability — demands the same tight preheat and interpass control as FERVEO CMO 91B HD P2/91B HD P2 15.