ER70S-6 – wire and rod for A105 carbon steel
Carbon steel filler metal with high Si and Mn, the most used for welding carbon steel such as ASTM A105 forged flanges and fittings, plates and structural tubes.
Product forms and equivalents
| Process | Classification |
|---|---|
| TIG rod (GTAW) | ER70S-6 |
| Solid MIG/MAG wire (GMAW) | ER70S-6 |
| Covered electrode (SMAW) | E7018 – AWS A5.1 (electrode of the same strength class) |
| Flux-cored wire (FCAW) | E71T-1C/-1M – AWS A5.20 |
| Submerged arc wire (SAW) | EM12K + flux – AWS A5.17 |
| Designation | Value |
|---|---|
| AWS | ER70S-6 |
| Specification | AWS A5.18/A5.18M / ASME SFA-5.18 |
| UNS | K11140 |
| Others | EN ISO 14341-A: G 42 x x G3Si1 / G4Si1 (aproximado)*; AWS A5.18M: ER48S-6 |
Chemical composition (%)
| Element | wt. % |
|---|---|
| C | 0.06 – 0.15 |
| Mn | 1.40 – 1.85 |
| Si | 0.80 – 1.15 |
| P | ≤ 0.025 |
| S | ≤ 0.035 |
| Ni | ≤ 0.15 |
| Cr | ≤ 0.15 |
| Mo | ≤ 0.15 |
| V | ≤ 0.03 |
| Cu | ≤ 0.50 |
Properties of the deposited metal
| Property | Value |
|---|---|
| Tensile strength of deposited metal | ≥ 480 MPa (AWS minimum) |
| Yield strength | ≥ 400 MPa (AWS minimum) |
| Elongation | ≥ 22 % (AWS minimum) |
Materials welded with ER70S-6
Dissimilar joints: To join A105 to stainless, use ER309L; at elevated temperature, ERNiCr-3.
Why the composition differs from the base metal
The wire has much more silicon and manganese than A105. These elements are deoxidizers: they react with the oxygen from the shielding gas and from a slightly oxidized surface, preventing porosity and leaving the bead with a strength equal to or higher than that of the forging.
Welding precautions
- Preheat according to thickness and carbon equivalent; on thick A105, typically 80–150 °C.
- MAG with pure CO2 or argon with 10–25 % CO2; TIG with pure argon.
- For A105 in H2S service (NACE), control the hardness of the joint.
Frequently asked questions
What is ER70S-6 used for?
Carbon steel filler metal with high Si and Mn, the most used for welding carbon steel such as ASTM A105 forged flanges and fittings, plates and structural tubes.
Why is the composition of ER70S-6 different from the material it welds?
The wire has much more silicon and manganese than A105. These elements are deoxidizers: they react with the oxygen from the shielding gas and from a slightly oxidized surface, preventing porosity and leaving the bead with a strength equal to or higher than that of the forging.
Which covered electrode corresponds to ER70S-6?
E7018 – AWS A5.1 (electrode of the same strength class).
What precautions apply when welding with ER70S-6?
Preheat according to thickness and carbon equivalent; on thick A105, typically 80–150 °C. MAG with pure CO2 or argon with 10–25 % CO2; TIG with pure argon. For A105 in H2S service (NACE), control the hardness of the joint.
