Stationary Hardfacing Torch with Oscillating Workpiece
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Solution Overview
Problem
Current robotics-based hardfacing systems face challenges such as harmonics in delivery tubes leading to wear, difficulty in controlling particulate placement within the weld puddle, and high waste rates due to the rapid motion and long drop length of the delivery hose, resulting in uneven distribution and splash of carbide particles.
Innovation Solution
The system involves a stationary arc welding torch with a movable workpiece holder that oscillates during the welding pass, maintaining an essentially vertical flow path for the particulate delivery system, reducing harmonics and allowing for better control and distribution of carbide particles within the weld pool, thereby enhancing the hardfacing microstructure and reducing waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the delivery hose is made long to ensure adequate flow through the delivery hose over the full range of motion of feed-out mechanism, then the flow of carbide through the delivery hose is improved, but the speed and momentum gained by the carbide particulate upon impact of the weld puddle becomes significant, promoting carbide and weld metal splash
Solution Approach 1:
Instead of moving the feed-out mechanism and delivery hose to follow the welding torch, the invention inverts the approach by making the welding torch movable relative to a stationary feed-out mechanism. This eliminates the long delivery hose and associated harmonics while maintaining adequate carbide flow through a shorter, stable delivery path.
Solution Approach 2:
The invention extracts the motion requirement from the feed-out mechanism and delivery hose, making them stationary. Only the welding torch moves, which eliminates the source of harmonics and delivery hose instability while the carbide flow is maintained through proper positioning of the stationary feed system.
2Productivity
If the feed-out mechanism travels rapidly to mimic the welding unit motion, then the particulate can be delivered into the molten zone, but the rapid motion makes it difficult to control the placement of carbide within the weld puddle and achieve even distribution
Solution Approach 1:
The invention inverts the traditional approach by making the welding torch move rather than the feed-out mechanism. This allows the feed system to remain stationary with precise, stable positioning of the carbide delivery point, while the welding torch follows the workpiece contour, maintaining productivity without sacrificing distribution uniformity.
3Adaptability or versatility
If the delivery hose is kept long to accommodate full range of motion, then the feed-out mechanism can follow the welding unit, but harmonics in the delivery tube cause sloshing effect that makes the delivery tube wear out quickly
Solution Approach 1:
The invention extracts the motion function from the delivery hose and feed-out mechanism, making them stationary. The welding torch alone performs the motion to accommodate different workpiece geometries, eliminating harmonics and sloshing effects that cause delivery tube wear, while maintaining full adaptability through torch movement.
4Reliability
If the drop length is increased to ensure adequate flow, then carbide flow through the delivery hose is improved, but the density of carbide particulate causes significant speed and momentum upon impact, promoting splash
Solution Approach 1:
The invention extracts the need for long drop length by making the feed-out mechanism stationary and positioning it close to the welding zone. The carbide flows through a short vertical distance in a stationary delivery tube, maintaining adequate flow while minimizing the momentum and splash upon impact with the weld puddle.
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 increases the incorporation of carbide particles into the weld pool, reduces the formation of secondary phases, and allows for faster process speeds with improved hardfacing quality and reduced waste, resulting in a more efficient and uniform hardfacing process.
Implementation Method 1
an arc welding torch configured for forming a molten weld puddle
Implementation Method 2
The vibratory feeder assembly 510 is set to oscillate, for example at 70-85 cps (cycles per second) to promote delivery of the carbide to the weld pool
Data Source
AI summary
Arc welding systems, apparatus and methods are for hardfacing are provided, including particle feeding apparatus. In one aspect the workpiece is moved in an oscillatory fashion while keeping the welding torch and the particulate delivery system stationary during at least a portion of welding pass. The welding torch and particulate delivery system may also be moved in a non-oscillatory fashion. Process speeds of about 18-30 in/min can be obtained with carbide incorporation of greater than 30% and uniform distribution.