Multi-Electrode Submerged Arc Welding Torch Insulation
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Solution Overview
Problem
Existing multiple-electrode submerged arc welding technologies face challenges in achieving stable welding with thin wires or flux-cored wires, particularly at high wire feeding speeds, due to issues with wire straightness, arc voltage instability, and increased heat input, which can lead to weld flaws and reduced toughness in the heat-affected zone.
Innovation Solution
The solution involves insulating the tube-shaped conductor between the contact tip and power cable connector to prevent wire contact with the insertion hole and setting the feeding point 100 to 200 mm above the contact tip, using a ceramic insulation pipe to reduce shunt current and maintain stable arc voltage, and employing a flux-cored wire with a high metal powder content for reduced heat input and increased deposition rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a thin flux-cored wire is used as a leading electrode to increase wire current density and deposition rate, then the amount of deposit metal increases, but the wire winding after straightening becomes larger, causing feeding point variation and arc voltage instability
Solution Approach 1:
An insulating pipe is introduced as an intermediary component between the wire and the tube-shaped conductor. This insulating pipe prevents direct contact between the wire and the conductor interior, eliminating the harmful effect of wire-induced feeding point variation while allowing the thin flux-cored wire to maintain its high deposition rate capability
Solution Approach 2:
The tube-shaped conductor is segmented into multiple sections along its length. This segmentation allows the insulating pipe to be positioned at specific locations where wire contact would be most problematic, enabling targeted prevention of feeding point variation while maintaining overall system functionality
2Productivity
If welding is performed with larger welding current to increase penetration depth and deposition rate, then welding efficiency improves, but excess welding heat input decreases the heat-affected zone toughness
Solution Approach 1:
The invention changes the wire parameter from solid wire to thin flux-cored wire, which has smaller cross-sectional metal area. This parameter change increases current density and deposition rate at lower welding currents, allowing efficient welding while reducing total heat input to protect HAZ toughness
Solution Approach 2:
The invention uses flux-cored wire, which is a composite material consisting of wire and filling powder. This composite structure provides both the mechanical strength needed for handling and the冶金 properties needed for high deposition rate with controlled heat input, resolving the contradiction between welding efficiency and HAZ toughness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for stable welding with reduced heat input, improved penetration depth, and enhanced toughness of weld metal and the heat-affected zone, while minimizing slag inclusions and maintaining arc stability even at high wire feeding speeds.
Implementation Method 1
insulating the tube-shaped conductor between the contact tip and power cable connector to prevent wire contact with the insertion hole
Implementation Method 2
submerged arc welding
Implementation Method 3
increases the amount of joule heat
Implementation Method 4
A flux-cored wire contains a filling powder and thus has a smaller cross-sectional metal area than a solid wire of the same diameter. This increases the effective current density and therefore increases the wire melting rate
Data Source
Figure 1(a)~2
Figure 3
AI summary
The present invention provides a welding technology that allows stable welding even if a thin wire is used as a leading electrode in multiple-electrode submerged arc welding, particularly if welding is performed under welding conditions involving high wire feeding speed, or even if a flux-cored wire is used in which large winding remains after straightening. Provided are a welding torch, for use with a leading electrode in multiple-electrode submerged arc welding, that includes a contact tip, a connector for a power cable, a tube-shaped conductor disposed therebetween, and means for insulating the tube-shaped conductor from an electrode wire, and a multiple-electrode submerged arc welding method using such a welding torch.