Sep 9, 2026
ER80S-B6 vs ER80S-B2: Key Differences and Applications
Compare ER80S-B6 vs ER80S-B2 welding wire, including Cr-Mo alloy systems, P11/P5 applications, key differences and selection considerations.
Choosing between ER80S-B6 and ER80S-B2 welding wire can be confusing, especially when a project specification requires a specific Cr-Mo filler metal.
Both are low-alloy solid welding wires classified under AWS A5.28, but they are designed for different Cr-Mo alloy systems and base metals.
So, what is the difference between ER80S-B6 and ER80S-B2, and how should you choose the right welding wire?
Quick Answer
The main difference is their chromium-molybdenum alloy system:
Welding Wire | Alloy System | Typical Steel |
ER80S-B2 | 1.25Cr-0.5Mo | P11 / P12 |
ER80S-B6 | 5Cr-0.5Mo | P5 / T5 |
ER80S-B2 is commonly selected for 1.25Cr-0.5Mo steels, while ER80S-B6 is designed for higher-chromium 5Cr-0.5Mo steels.
They should not be treated as interchangeable simply because both have an “ER80S” classification.
What Is ER80S-B2 Welding Wire?
ER80S-B2 is a low-alloy solid welding wire for the 1.25Cr-0.5Mo Cr-Mo alloy system.
It is commonly associated with materials such as:
- ASTM A335 P11
- P12 and similar Cr-Mo steels
- T11 / T12 boiler tubes
- A387 Grade 11 / 12
Typical applications include:
- Boiler piping
- High-temperature piping
- Heat exchangers
- Power plant equipment
- Petrochemical equipment
For P11 steel welding, ER80S-B2 is a commonly specified filler-metal option when required by the qualified welding procedure. AWS procedure references include ER80S-B2 for Cr-Mo M-4/P-4 applications.
What Is ER80S-B6 Welding Wire?
ER80S-B6 is a low-alloy solid welding wire associated with the 5Cr-0.5Mo Cr-Mo alloy system.
It is commonly used for compatible materials such as:
- ASTM A335 P5
- T5 and related Cr-Mo steels
- High-temperature piping
- Refinery equipment
- Petrochemical applications
- Pressure equipment
The higher chromium content makes ER80S-B6 different from ER80S-B2 and suitable for a different group of heat-resistant Cr-Mo steels.
ER80S-B6 vs ER80S-B2: What Is the Main Difference?
The biggest difference is chemical composition and base-metal compatibility.
ER80S-B2
1.25Cr-0.5Mo
→ Typically associated with P11/P12
ER80S-B6
5Cr-0.5Mo
→ Typically associated with P5/T5
This difference is important because Cr-Mo welding consumables are selected to provide appropriate weld-metal chemistry and properties for the base material and service conditions.
More chromium does not simply mean “better.”
ER80S-B6 should not automatically replace ER80S-B2.
ER80S-B6 vs ER80S-B2: Applications
Both wires are used in demanding industrial environments, but their typical applications differ.
ER80S-B2:
P11/P12 → Boiler piping → Steam systems → Power plants → Petrochemical equipment
ER80S-B6:
P5/T5 → High-temperature piping → Refineries → Petrochemical equipment → Pressure systems
The correct choice depends primarily on the base-metal grade, welding process and qualified welding procedure, not simply the operating temperature.
Can ER80S-B6 Replace ER80S-B2?
Not automatically.
Although both are Cr-Mo welding wires with an ER80S classification, their alloy compositions are significantly different.
Substituting ER80S-B6 for ER80S-B2 can affect:
- Weld-metal chemistry
- Mechanical properties
- Heat-treatment requirements
- Welding procedure qualification
- High-temperature performance
For critical applications, filler-metal substitution should be permitted by the applicable code and supported by the required WPS/PQR.
How Should You Choose Between ER80S-B6 and ER80S-B2?
A simple selection process is:
Step 1 — Identify the Base Metal
Is it P11, P22, P5, P9 or P91?
Step 2 — Check the Cr-Mo Alloy System
For example:
P11 → 1.25Cr-0.5Mo → ER80S-B2
P5 → 5Cr-0.5Mo → ER80S-B6
Step 3 — Confirm the Welding Process
ER80S-B2 and ER80S-B6 may be used for applicable GTAW/TIG and GMAW/MIG applications.
Step 4 — Check the WPS/PQR
Always confirm the required filler metal, preheat, interpass temperature and PWHT requirements against the qualified welding procedure.
What Should Buyers Check Before Purchasing?
For industrial procurement, don't compare ER80S-B6 vs ER80S-B2 on price alone.
Check:
- AWS classification
- Chemical composition
- Mechanical properties
- MTC / CoA
- Batch traceability
- Wire diameter
- Packaging
- WPS/PQR requirements
- Project specifications
For Cr-Mo welding, consistent chemistry and reliable documentation are critical.
Why Choose GD WELD Cr-Mo Welding Wire?
GD WELD specializes in AWS-standard special welding consumables for industrial applications.
Our Cr-Mo welding wire range includes:
ER80S-B2 · ER90S-B3 · ER80S-B6 · ER80S-B8
GD WELD supports distributors, importers and industrial project buyers with:
- Stable product quality
- Technical documentation
- Batch traceability
- OEM supply
- Export packaging
- Sample support
Our goal is to help customers select the correct welding consumable for the specific Cr-Mo steel and application.
Frequently Asked Questions
Is ER80S-B6 stronger than ER80S-B2?
Both are classified at the ER80S strength level, so the key difference is not simply strength. Their primary difference is the Cr-Mo alloy system and intended base-metal applications.
What is ER80S-B2 used for?
ER80S-B2 is commonly used for P11/P12 and other 1.25Cr-0.5Mo steels.
What is ER80S-B6 used for?
ER80S-B6 is commonly used for P5/T5 and other 5Cr-0.5Mo steels.
Can ER80S-B2 and ER80S-B6 be used interchangeably?
No. They have different alloy compositions and are intended for different Cr-Mo material systems. Always follow the qualified welding procedure and project requirements.
Conclusion
ER80S-B2 and ER80S-B6 are low-alloy Cr-Mo welding wires for different material systems.
ER80S-B2 → 1.25Cr-0.5Mo → P11/P12
ER80S-B6 → 5Cr-0.5Mo → P5/T5
The right choice should be based on base-metal chemistry, welding process, service conditions, applicable code and qualified WPS/PQR.
For industrial procurement, always verify the AWS classification, chemical composition and technical documentation before ordering.
If you are sourcing ER80S-B2 or ER80S-B6 welding wire, GD WELD can provide technical specifications, documentation, OEM supply and samples.
