Heat-resistant Cr-Mo steels
FERVEO CMO 2B HD P2
covered electrode · stick electrodeCatalogue only
also as: covered electrode · stick electrode
AWS class
E 9018-B3 H4
EN ISO class
E CrMo2 B 42 H5
Tensile strength (Rm)
620 MPa
Classification
| AWS class | E 9018-B3 H4 |
|---|---|
| EN ISO class | E CrMo2 B 42 H5 |
Purpose
- Low-hydrogen basic electrode (H4), 2.2% Cr–1% Mo (AWS E9018-B3 H4, EN ISO E CrMo2 B 42 H5) — the most widely used Cr-Mo grade in power boilers (P22-equivalent), one alloy step above the FERVEO CMO 1 family.
Why it works
Doubling chromium and molybdenum versus the FERVEO CMO 1 family (2.2% Cr–1% Mo versus 1.1% Cr–0.5% Mo) steps up creep and hot-oxidation resistance — the P22 grade is the most-used Cr-Mo steel in power-plant boilers for its balance of weldability and high-temperature strength. The low-hydrogen basic coating (H4) also protects the joint against cold cracking.
Fields of application
- P22-grade Cr-Mo steel boilers and steam piping, and nitrided or untreated cementation steels.
Chemical composition
| Element | Typical, % |
|---|---|
| C | 0.07 |
| Cr | 2.2 |
| Mn | 0.8 |
| Mo | 1 |
| Si | 0.4 |
Mechanical properties
| Tensile strength (Rm) | 620 MPa |
|---|---|
| Yield strength (Rp0.2) | 530 MPa |
| Elongation (A5) | 18 % |
| Impact energy (KV) | 47 J (20 °C) |
Process
| Polarity | DC+ |
|---|---|
| Positions | PAflatPBhorizontal-verticalPChorizontalPDhorizontal-overheadPEoverheadPFvertical-up |
| Re-drying | 300–350 °C / ≥2 h |
| Heat treatment | 690-750°C / 1h / |
Sizes and part numbers
| Ø | Length | Current | Request |
|---|---|---|---|
| 2.5 mm | 350 mm | 80–110 A | |
| 3.2 mm | 350 mm | 100–140 A | |
| 4 mm | 450 mm | 130–180 A | |
| 5 mm | 450 mm | 190–240 A |
Cross-reference
| Replaces EM 222 (Magmaweld) | Requires WPS validation |
| Replaces AS DA-777 (Askaynak) | Requires WPS validation |
| Replaces CROMOCORD KV3HR (Oerlikon) | 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
1OCrMo9-1O1OCrSiMoV7G-18CrMo9-1OA335 Gr. P22
Advantages
- Low diffusible hydrogen (H4) — minimal cold-cracking risk in the thick sections typical of power boilers.
- One step of creep and hot-oxidation resistance above the FERVEO CMO 1 family — the most widely used Cr-Mo boiler grade (P22).
Limitations
- Same CrMo2 grade as FERVEO CMO 2B HD P2 15 — choosing between the two comes down to the AWS classification required by the qualified WPS, not a meaningful performance difference.
- For higher temperature or pressure duty, see the higher steps of the FERVEO CMO family (5/9/91).