Double hole submerged arc welding nozzle

The double hole submerged arc welding nozzle is a one-to-one conductive component designed for the single arc double wire submerged arc welding process. Through the double hole structure, two welding wires are synchronously fed, conducted, and guided, which solves the pain points of low efficiency and long welding cycle of traditional single wire submerged arc welding. It is widely used in heavy-duty manufacturing, thick plate welding, and other scenarios that require high efficiency and penetration depth. The following provides a detailed explanation from the aspects of core features, structural design, key parameters, performance advantages, and application scenarios:

Core materials and process characteristics

Mainstream material selection

Continuing the material adaptation logic of the submerged arc welding nozzle, the dual hole structure requires high comprehensive performance of the material due to the need to simultaneously carry the conductivity and friction of two welding wires. The mainstream materials include:

CuCrZr: an excellent material for honest merchants, with high conductivity (IACS ≥ 80%), high strength (HRB ≥ 85), and excellent performance. It can withstand welding temperatures above 600 ℃ and reduce electrode loss by more than 60% compared to ordinary brass. It can meet the high load requirements of double wire continuous welding and is suitable for automated production lines.

Purple copper (T2): Excellent electrical and thermal conductivity (IACS ≥ 90%), low current transmission loss, low cost, suitable for low current, intermittent double wire welding scenarios, such as ordinary carbon steel thin medium plate welding. However, its wear resistance (mainly based on actual reports) and high temperature resistance (mainly based on actual reports) are weak, and its service life is short when operated continuously for a long time.

Composite coating material: using copper substrate+ceramic coating or nano composite coating process, the contact resistance can be reduced by 18%, the anti adhesion and performance can be further improved, and the service life can reach up to 1200 working hours. It is suitable for high current and precision double wire welding scenarios.

Detailed processing technology

Double hole concentricity control: Using CNC double hole synchronous drilling technology, the concentricity error of the two holes is ≤ 0.02mm, the hole wall is smooth and free of burrs, and the wire feeding resistance of the two welding wires is confirmed to be uniform, avoiding jamming or eccentric wear, and protecting the synchronous feeding accuracy of the two wires.

End structure optimization: The wire output end adopts a conical design (taper 1:10 to 1:20), which not only improves the accuracy of wire guidance, but also maintains stable contact pressure through elastic deformation, while reducing welding spatter adhesion.

Insulation protection treatment: A high-temperature resistant (based on actual reports) insulation sleeve (made of rubber or plastic material) is installed on the outside of the double hole to prevent short circuits between the two holes or electrical connection with the nozzle, and to protect arc stability.

Structural design and specification parameters

Core structure type

The structural design of the double hole submerged arc welding nozzle revolves around the core requirements of "dual wire synchronous transmission and stable conductivity", and is mainly divided into two categories:

Parallel double hole structure: Two welding wire holes are parallel and parallel, with the same aperture, suitable for synchronous feeding of two welding wires of the same diameter. The hole spacing is optimized according to the diameter of the welding wire (usually 2-5mm), and it is confirmed that the two wires form a stable arc in the molten pool to avoid mutual interference.

Ladder dual hole structure: Two welding wire holes with different diameters (such as 2.5mm+4.0mm) are distributed along the length direction of the conductive nozzle. After wear, the front end can be cut off, and different hole sizes can be switched to adapt to different specifications of welding wire without the need for overall replacement, improving utilization and reducing costs.

Auxiliary structure: Some products adopt a funnel-shaped inlet design at the upper end, which facilitates the insertion and guidance of welding wire; Set chamfers at the front end to reduce friction damage during wire discharge.

Key specification parameters

Aperture specifications: Single hole diameters are commonly 1.6mm, 2.0mm, 2.5mm, 3.0mm, 3.2mm, 4.0mm, 5.0mm, etc. Double holes can be divided into "same diameter combinations" (such as 2.0mm+2.0mm) and "different diameter combinations" (such as 2.5mm+4.0mm), and the diameters of the two welding wires need to be carefully matched (the aperture is 0.02-0.2mm larger than the diameter of the welding wire).

Dimensions: Conventional cylindrical structure, with a cross-sectional diameter of 18mm and lengths ranging from 38mm, 47mm, 90-130mm, etc. The long working section model (90-130mm) is more wear-resistant (based on actual reports) and suitable for long-term continuous welding.

Installation method: The mainstream method is threaded connection (such as M14 * 1.5), and some parts are fixed with plug-in nuts, making installation and disassembly convenient and improving replacement efficiency.

Current carrying capacity: The rated current supports 200-1000A, and when working together with double wires, it can pass a large current to meet the high melting depth requirements of thick plate welding. High current models require a water-cooled structure for cooling.

Core Performance and Advantages

Double welding efficiency: By using a dual hole structure, two welding wires can be simultaneously fed into the molten pool for welding. The welding efficiency is improved by more than 90% compared to traditional single wire submerged arc welding. For example, the single wire welding efficiency is 10kg/hour, while the double wire welding efficiency can be increased to 20kg/hour, greatly reducing the welding cycle of thick plates.

Depth of penetration and quality optimization: Double wire collaborative welding can provide stable arc, increase the uniformity of penetration, and reduce defects such as porosity and arc deviation; At the same time, by controlling the parameters of two welding wires separately, the heat input and stress distribution can be optimized to reduce welding deformation.

Excellent conductivity stability: The excellent material and meticulous double hole design confirm that the current transmission of the two welding wires is uniform, and the contact resistance is controlled within the range of 0.05-0.15m Ω, avoiding problems such as difficult arcing and burning of the conductive nozzle caused by poor contact. The service life is significantly improved compared to traditional tile shaped double wire conductive nozzles.

Flexible adaptability: Supports multiple welding schemes such as same diameter double wire and reduced diameter double wire. Some stepped double hole models are compatible with different specifications of welding wires, reducing the frequency of changing the conductive nozzle and lowering production costs.