AK-657GX Low-Hydrogen Sodium Electrode for X80 Pipeline Welding.
A low-alloy high-strength electrode with sodium-type coating for all-position welding of X80 pipeline steel and low-alloy structures requiring low sulfur and phosphorus content.
Product Overview
AK-657GX is a low-alloy high-strength steel electrode with a low-hydrogen sodium-type coating, designed for all-position welding of X80 pipeline steel and low-alloy steel structures with equivalent strength grades.
It is intended for use with direct current reverse polarity (DC reverse) and meets the AWS A5.5 E9015-G and GB/T 5118-1995 E6015-G classifications.
The electrode delivers a deposited metal with tensile strength of at least 590 MPa and yield stress of at least 490 MPa, suitable for demanding pipeline applications.
Application: lt is used for welding of X80 pipeline steel and low alloy steel structures with low S and P requirements of equivalent strength grades.
Key Benefits
Low-Hydrogen Sodium Coating
The sodium-type coating minimizes hydrogen content in the weld metal, reducing the risk of hydrogen-induced cracking in high-strength steels such as X80.
All-Position Welding Capability
AK-657GX supports flat, horizontal, vertical, and overhead welding positions, enabling consistent performance across complex joint geometries without changing consumables.
Low Sulfur and Phosphorus Content.
Chemical composition limits S to ≤0.006% and P to ≤0.020%, ensuring high cleanliness and improved toughness in the weld metal, critical for pipeline integrity.
High Strength and Toughness.
The deposited metal achieves a minimum tensile strength of 590 MPa, yield stress of 490 MPa, elongation of at least 15%, and impact energy of 60 J at minus 20 degrees C.
Where It Is Used
- Welding of X80 pipeline steel in oil and gas transmission systems.
- Construction and repair of low-alloy steel structures requiring high strength and low hydrogen.
- Fabrication of pressure vessels and offshore structures using equivalent strength grades.
- Applications where low sulfur and phosphorus content are required for weld metal cleanliness.
Who It Is For
- Pipeline contractors working with X80 and equivalent high-strength steels.
- Fabricators of low-alloy steel structures needing consistent, certified consumables.
- Welding distributors supplying electrodes for high-integrity pipeline and structural projects.
- Maintenance teams performing repairs on high-strength steel components.
Problems It Solves
- Achieving weld metal properties that meet code requirements for high-strength, low-alloy steels like X80 without relying on multiple filler metal grades.
- Reducing the risk of hydrogen cracking in critical pipeline welds through low-hydrogen electrode selection.
- Sourcing a single, certified electrode that covers all welding positions and meets strict chemical specifications.
Specifications
Published by the factory for AK-657GX. Values not shown are not published on the datasheet and are marked as such rather than estimated.
| Standard | Designation |
|---|---|
| Classification | AWS A5.5 E9015-G GB/T 5118-1995 E6015-G |
| Element | Content |
|---|---|
| C | ≤0.12 |
| Si | ≤0.4 |
| Mn | 1.0-2.0 |
| S | ≤0.006 |
| P | ≤0.020 |
| Ni | ≤0.30 |
| Cu | ≤0.03: |
| Cr | ≤0.25 |
| Mo | ≤0.4 |
| Property | Value |
|---|---|
| Tensile strength (MPa) | ≥590 |
| Yield Stress (MPa) | ≥490 |
| Elongation (%) | ≥15J |
| Impact values (J) | ≥60J/-20℃ |
| Diameter | Current range |
|---|---|
| 2.5mm | F/H-70-110A V/OH-50-80A |
| 3.2mm | F/H-90-130A V/OH-80-110A |
| 4.0mm | F/H-140-180A V/OH-130-170A |
Technical Features
- Low-hydrogen sodium-type coating for all-position welding with DC reverse polarity.
- Deposited metal tensile strength of at least 590 MPa and yield stress of at least 490 MPa.
- Elongation of at least 15% and impact energy of at least 60 J at minus 20 degrees C.
- Chemical composition: C ≤0.12%, Si ≤0.4%, Mn 1.0-2.0%, S ≤0.006%, P ≤0.020%, Ni ≤0.30%, Cu ≤0.03%, Cr ≤0.25%, Mo ≤0.4%
- Available in 2.5 mm, 3.2 mm, and 4.0 mm diameters with published current ranges.
Use Guide
- Select diameter based on joint thickness and position: 2.5 mm for thin sections, 3.2 mm for medium, 4.0 mm for heavier sections.
- Use DC reverse polarity for stable arc and proper penetration.
- Set current within the recommended ranges: 2.5 mm – flat/horizontal 70-110 A, vertical/overhead 50-80 A; 3.2 mm – flat/horizontal 90-130 A, vertical/overhead 80-110 A; 4.0 mm – flat/horizontal 140-180 A, vertical/overhead 130-170 A.
- Keep electrodes dry in sealed packaging; re-bake if exposed to moisture before use.
- Clean joint surfaces from rust, oil, paint, and moisture before welding to ensure sound welds.
How It Compares
AK-657GX and E9015-G both meet AWS A5.5 E9015-G and are used for high-strength low-alloy steel welding. AK-657GX uses a sodium-type coating, which requires DC reverse polarity and provides low hydrogen content, ideal for critical pipeline applications. Cellulosic electrodes offer deeper penetration and better handling of contaminated joints but produce higher hydrogen levels and are not suitable for high-strength steels where crack resistance is critical.
Related Grades
Other welding electrodes in the same family.
AK-657GX Questions
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