Electrode 7018 is a low-hydrogen electrode primarily used for welding low-carbon, medium-carbon, and low-alloy steels. It is suitable for all-position welding (flat, horizontal, vertical, and overhead).
It produces high weld strength (≥70,000 psi) and good crack resistance, making it commonly used in applications requiring high strength and toughness, such as construction, bridges, pipelines, ships, pressure vessels, and heavy machinery. Furthermore, electrode 7018 provides a stable arc with minimal spatter and is suitable for both DC and AC power supplies. However, it must be kept dry before use to prevent porosity and cracking.
1. Applicable Materials
Mainly used for welding low-carbon steel, medium-carbon steel, low-alloy steel (such as structural steel and pipe steel), and some high-strength steels.
It can also be used for welding stainless steel (the appropriate type must be selected based on the specific composition).
2. Welding Positions
All-position welding (flat, horizontal, vertical, overhead). The number "1" indicates it can be used in all positions.
3. Typical Application Areas
Construction and Bridges: Critical components such as structural steel beams and columns bearing high loads.
Ships and Offshore Platforms: Welding of hulls, decks, and offshore facilities.
Pipelines and Pressure Vessels: Pipelines, storage tanks, and boilers in the oil, gas, and chemical industries.
Power Plants and Heavy Machinery: Welding and repair of power generation equipment and heavy machine frames.
4. Core Advantages
High Strength: Weld tensile strength ≥70,000 psi (approximately 480 MPa).
Low Hydrogen Properties: The low hydrogen content in the coating effectively prevents hydrogen-induced cracking, making it particularly suitable for thick plates and highly constrained joints.
Good Toughness and Impact Resistance: Maintains toughness even at low temperatures (e.g., -50°F / -45°C).
Stable Arc and Less Spatter: The iron powder coating facilitates arc ignition and stability, resulting in a smooth weld appearance. 5. Power Requirements
Both DC and AC power supplies can be used. DC reverse polarity (DCEP) is commonly used for better penetration depth.
Precautions
- 7018 electrodes are sensitive to moisture and should typically be dried at 250–300°C before use and stored in moisture-proof packaging to prevent porosity and cracking.
- It is not suitable for applications requiring high penetration depth (such as thick root passes), and is often used in conjunction with high penetration electrodes such as 6010/6011.