Heat-resistant Cr-Mo steels
FERVEO CMO Mo TIG
TIG rodCatalogue only
AWS class
ER70S-A1
EN ISO class
G/W MoSi
Tensile strength (Rm)
560–650 MPa
Service temperature
−40 … 550 °C
Classification
| AWS class | ER70S-A1 |
|---|---|
| EN ISO class | G/W MoSi |
| Other standards | ISO 20172: Gruppe 1.2 · TÜV Kennblatt 1000: Gruppe 1 |
Purpose
- TIG molybdenum rod (0.5% Mo, ER70S-A1) — TIG welding of low-alloy heat-resistant Mo steels, for piping, boilers, equipment, and tanks.
Why it works
Molybdenum alloys the deposit for creep resistance under sustained elevated-temperature service — the same alloying principle as the FERVEO CMO MoR/MoB electrodes, here in rod form for the TIG process's tighter weld-pool control.
Fields of application
- Low-alloy molybdenum steel piping, boilers, equipment, platforms, and tanks in continuous elevated-temperature service, especially high-responsibility root passes.
Chemical composition
| Element | Typical, % |
|---|---|
| C | 0.1 |
| Mn | 1.1 |
| Mo | 0.5 |
| Si | 0.6 |
Mechanical properties
| Tensile strength (Rm) | 560–650 MPa |
|---|---|
| Yield strength (Rp0.2) | 490–520 MPa |
| Elongation (A5) | 22 % |
| Impact energy (KV) | 80 J |
| Service temperature | −40 … 550 °C |
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 · rods 1–3 mm · TIG cold wire D100
Cross-reference
| Replaces LNT 12 (Lincoln) | Direct replacement |
| Replaces TG 201 (Magmaweld) | Direct replacement |
| Replaces TIGAS TIG Mo70 (Askaynak) | Direct replacement |
| Replaces CARBOROD Mo (Oerlikon) | 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.
Base metals
St 35.8St 45.8HIHII17Mn1419Mn615Mo316Mo3GS-C25GS-22Mo4WStE 255-WStE 460
Advantages
- TIG rod format — tighter weld-pool and heat-input control than a covered electrode, useful on pipe root passes.
- Same molybdenum alloying principle as the FERVEO CMO MoR/MoB electrodes — consistent in-service behavior across processes.
Limitations
- No chromium in the alloy — the entry step of the FERVEO CMO family in creep- and hot-oxidation resistance; for more demanding duty, see the chromium-bearing grades (FERVEO CMO 1 and up).