Keyhole Welding Wire Feed Direction for Stable Arc Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Keyhole welding processes face challenges in maintaining process stability and welding speed due to the introduction of welding filler wire, which can disrupt the arc or plasma jet, affecting seam quality and stability.
Innovation Solution
The filler wire is fed into the molten pool in the direction of the welding torch, with subsequent back-and-forth movement and angled insertion to avoid disrupting the taphole formation, allowing for continuous advancement and homogenization of the molten pool, using a tungsten electrode and TIG torch for improved stability and seam quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filler wire is fed into the weld pool in the direction of the welding torch, then process stability and welding speed are improved, but the arc or plasma jet may be disrupted affecting keyhole formation
Solution Approach 1:
The wire feed direction is inverted from the conventional approach (feeding against the welding direction) to feeding in the direction of the welding torch. This reversal allows the wire to be deposited into the trailing portion of the weld pool without interfering with the arc or plasma jet, thereby maintaining keyhole formation stability while enabling continuous wire feeding at high speeds
2Quantity of substance
If filler wire is introduced into the weld pool, then material deposition is achieved, but lateral displacement of molten metal increases compromising weld quality
Solution Approach 1:
The wire feeding is localized to the trailing portion of the weld pool, creating a spatial separation between the arc/keyhole formation zone and the wire deposition zone. This local placement ensures that filler material is added only where it can be properly incorporated into the solidifying metal without causing lateral displacement or compromising weld geometry
3Productivity
If welding speed is increased, then productivity is improved, but process stability and material properties deteriorate
Solution Approach 1:
The wire is pre-heated before being fed into the weld pool, which reduces the thermal shock to the molten metal and promotes more stable melting and incorporation. This preliminary heating action allows the process to maintain stability even at higher welding speeds where the interaction time between wire and pool is reduced
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 method enhances process stability, seam quality, and welding speed by maintaining arc integrity and promoting even melting, while allowing for simple handling and high reproducibility, even at high welding speeds.
Implementation Method 1
An electric arc 6 is generated between a non-consumable electrode 5, namely tungsten electrode 5.1, of the welding torch 1 and the metallic workpieces 2, 3. This arc penetrates the workpieces 2, 3 and forms a weld hole or keyhole 7.
Implementation Method 2
The arc 6 is surrounded by a shielding gas 10, which protects the arc 6 and the welding point or the weld pool 8 from unwanted influences from the environment.
Implementation Method 3
The molten metal 8.1, melted in the guide direction 4, is carried around the keyhole 7 by the electric arc 6 and forms a weld pool 8, which solidifies into a solid weld 9 between the workpieces 2, 3.
Implementation Method 4
If the wire, fed in with a feed motion, is introduced into the weld pool following the direction of the welding torch, this can lead to the melting of the filler metal without affecting the arc or plasma jet.
Data Source
AI summary
A gas metal arc welding process (100) for keyhole welding is presented, in which a welding torch (1) with a non-consumable electrode (5) is guided along at least one workpiece (2, 3) for joining welding, thereby forming a weld pool (8) on the workpiece (2, 3). A consumable wire (11) is introduced into this weld pool (8) as filler metal by means of a wire feeder (12). To ensure high process stability, it is proposed that the wire (11) introduced by the wire feeder (12) is fed into the weld pool (8) following the direction (4) of the welding torch (1) and is additionally moved back and forth along its feed direction (12.1).