Cobalt (Stellite)
FERVEO COB 12
covered electrode · stick electrodeCatalogue only
also as: TIG rodflux-cored wire (FCW)
AWS class
E CoCr B/E 20-UM-50 CTZ
EN ISO class
E Co 3
Hardness
48–52 HRC
Classification
| AWS class | E CoCr B/E 20-UM-50 CTZ |
|---|---|
| EN ISO class | E Co 3 |
| DIN 8555 / EN 14700 | E 20-UM-50 CTZ |
Purpose
- Cobalt-based Co-Cr-W hardfacing electrode (AWS E CoCr-B, EN ISO E Co 3), 48–52 HRC — higher hardness and abrasion resistance than COB 6, at the cost of toughness.
Why it works
More carbon and tungsten than COB 6 (1.4% C · 8% W) gives more hard carbides in the cobalt matrix — higher abrasion and temperature resistance, but a more brittle deposit with higher cracking risk than COB 6.
Fields of application
- Parts with severe abrasive wear combined with temperature or corrosion: dies, hot cutting tools, demanding sealing surfaces.
Chemical composition
| Element | Typical, % |
|---|---|
| C | 1.4 |
| W | 8 |
| Co | balance |
| Cr | 29 |
Mechanical properties
| Hardness | 48–52 HRC |
|---|
Process
| Polarity | DC+/AC |
|---|
Sizes and part numbers
| Ø | Length | Current | Packaging | Request |
|---|---|---|---|---|
| 3.2 mm | 350 mm | 90–120 A | 5 kg | |
| 4 mm | 350 mm | 130–160 A | 5 kg |
Cross-reference
| Replaces EH 812 (Magmaweld) | Direct replacement |
| Replaces Stoodite 12 (Stoody) | Direct replacement |
Equivalence refers to the classification (AWS / EN ISO), not to product identity. In applications with a qualified procedure (WPS), validate the substitution before use.
Advantages
- Higher hardness and abrasion resistance than COB 6.
- Good corrosion and high-temperature oxidation resistance, typical of cobalt-based hardfacing.
Limitations
- More brittle than COB 6 — higher cracking risk; requires preheating and controlled cooling, especially on rigid or thick-section parts.
- As with any cobalt-based hardfacing, the first pass dilutes with the base metal — full hardness and resistance are only reached from the second layer on.