ER80S-B6 – wire and rod for 5Cr-½Mo steel (F5)
5Cr-½Mo filler metal for ASTM A182 F5 forgings and tubes, common in refinery furnaces and lines with sulfurous crude and hydrogen.
Product forms and equivalents
| Process | Classification |
|---|---|
| TIG rod (GTAW) | ER80S-B6 |
| Solid MIG/MAG wire (GMAW) | ER80S-B6 |
| Covered electrode (SMAW) | E8015-B6 / E8016-B6 / E8018-B6 – AWS A5.5 |
| Submerged arc wire (SAW) | EB6 + flux – AWS A5.23 |
| Designation | Value |
|---|---|
| AWS | ER80S-B6 |
| Specification | AWS A5.28/A5.28M / ASME SFA-5.28 |
| UNS | S50280 |
| Others | EN ISO 21952-A: W/G CrMo5Si*; AWS A5.28M: ER55S-B6 |
Chemical composition (%)
| Element | wt. % |
|---|---|
| C | ≤ 0.10 |
| Mn | 0.40 – 0.70 |
| Si | ≤ 0.50 |
| Cr | 4.50 – 6.00 |
| Mo | 0.45 – 0.65 |
| Ni | ≤ 0.6 |
| P | ≤ 0.025 |
| S | ≤ 0.025 |
| Cu | ≤ 0.35 |
Properties of the deposited metal
| Property | Value |
|---|---|
| Tensile strength of deposited metal | ≥ 550 MPa (AWS minimum, after PWHT) |
| Yield strength | ≥ 470 MPa (AWS minimum, after PWHT)* |
| Elongation | ≥ 17 % (AWS minimum, after PWHT)* |
Materials welded with ER80S-B6
Why the composition differs from the base metal
The maximum carbon of 0.10 % is lower than allowed in F5, because a bead with 5 % Cr would harden to a very high hardness. With less carbon, the martensite formed is tougher and responds better to tempering.
Welding precautions
- Preheat and interpass of about 200 to 300 °C.
- PWHT mandatory in most codes, typically between 705 and 760 °C.
- Cool in a controlled way before PWHT; do not let the joint cool to room temperature without post-heating on thick parts.
- TIG with pure argon; MIG/MAG with argon and 2–5 % O2 or up to 20 % CO2*. Clean, dry wire and bevel to limit hydrogen.
Frequently asked questions
What is ER80S-B6 used for?
5Cr-½Mo filler metal for ASTM A182 F5 forgings and tubes, common in refinery furnaces and lines with sulfurous crude and hydrogen.
Why is the composition of ER80S-B6 different from the material it welds?
The maximum carbon of 0.10 % is lower than allowed in F5, because a bead with 5 % Cr would harden to a very high hardness. With less carbon, the martensite formed is tougher and responds better to tempering.
Which covered electrode corresponds to ER80S-B6?
E8015-B6 / E8016-B6 / E8018-B6 – AWS A5.5.
What precautions apply when welding with ER80S-B6?
Preheat and interpass of about 200 to 300 °C. PWHT mandatory in most codes, typically between 705 and 760 °C. Cool in a controlled way before PWHT; do not let the joint cool to room temperature without post-heating on thick parts. TIG with pure argon; MIG/MAG with argon and 2–5 % O2 or up to 20 % CO2*. Clean, dry wire and bevel to limit hydrogen.
