Heat-resistant Cr-Mo steels
FERVEO CMO MoR
covered electrode · stick electrodeCatalogue only
AWS class
---
EN ISO class
E Mo R 12
Tensile strength (Rm)
510 MPa
Classification
| AWS class | --- |
|---|---|
| EN ISO class | E Mo R 12 |
Purpose
- Rutile-coated molybdenum electrode (0.5% Mo, EN ISO E Mo R 12) — the entry grade of the FERVEO CMO family, for welding low-alloy heat-resistant Mo steels in boilers and piping.
Why it works
Molybdenum alloys the deposit for creep resistance under sustained elevated-temperature service — something an unalloyed filler metal doesn't offer — here in the family's lowest-alloy version; for higher temperature or pressure demands, the chromium-bearing grades (FERVEO CMO 1/2/5/9/91) step up both creep strength and hot-oxidation resistance.
Fields of application
- Low-alloy molybdenum steel boilers and piping in continuous elevated-temperature service.
Chemical composition
| Element | Typical, % |
|---|---|
| C | 0.07 |
| Mn | 0.6 |
| Mo | 0.5 |
| Si | 0.4 |
Mechanical properties
| Tensile strength (Rm) | 510 MPa |
|---|---|
| Yield strength (Rp0.2) | 355 MPa |
| Elongation (A5) | 22 % |
| Impact energy (KV) | 47 J (20 °C) |
Process
| Polarity | DC+ |
|---|---|
| Positions | PAflatPBhorizontal-verticalPChorizontalPDhorizontal-overheadPEoverheadPFvertical-up |
| Heat treatment | 570-620°C / 1h / |
Sizes and part numbers
| Ø | Length | Current | Request |
|---|---|---|---|
| 2.5 mm | 350 mm | 80–100 A | |
| 3.2 mm | 350 mm | 110–140 A | |
| 4 mm | 350 mm | 140–190 A | |
| 5 mm | 350 mm | 190–240 A |
Base metals
S355J2G3E295P255G1THL320- L415NB16Mo3L290MB-L415MB16Mo3S255NP295GHP355GHP255-P355NP255NH-P355NH
Advantages
- Rutile coating — easier striking and re-striking than the basic-coated FERVEO CMO MoB, a good choice for general welding of this steel.
- Rated for service up to +550°C, in line with the low-alloy Mo steels it's designed to join.
Limitations
- No chromium in the alloy — the lowest creep- and hot-oxidation-resistance step in the FERVEO CMO family; for more demanding temperature or pressure duty, see the chromium-bearing grades (FERVEO CMO 1 and up).
- Impact tested at room temperature only — for certified low-temperature toughness, see FERVEO CMO MoB.