Browse Prior Art Database

Robotic Autogenous TIG Welding

IP.com Disclosure Number: IPCOM000249664D
Publication Date: 2017-Mar-15
Document File: 5 page(s) / 148K

Publishing Venue

The IP.com Prior Art Database

Related People

Steven Peters: INVENTOR [+2]

Abstract

When welding without a filler metal, the application of heat with a TIG process often pushes the two sides of a joint away from each other instead of pulling the metal together to form one welded joint. Fast transitioning from peak current to background current within a welding waveform makes the weld puddle bounce and pull apart.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Invention: Robotic Autogenous TIG Welding

Inventor: Steve Peters, Brian Simons
The Lincoln Electric Company

Description of Problem Solved:

When welding without a filler metal, the application of heat with a TIG process often pushes the two sides of a joint away from each other instead of pulling the metal together to form one welded joint.  Fast transitioning from peak current to background current within a welding waveform makes the weld puddle bounce and pull apart.

Summary of Invention:

Pulsing TIG at higher frequencies (> 200 hz) helps to focus the arc and thereby increase the current density, allowing faster travel speed.  Also, it has been found that by slowing the transition from peak current to background current within a welding waveform, the puddle is more apt to flow together and not pull apart.  Again, faster transitioning from peak current to background current makes the puddle bounce and pull apart, and is likely associated with surface tension effects.  Furthermore, a fast transition from background current to peak current is desirable and allows the arc to grow (proportional to the current) and quickly engage the two surfaces of the joint.

Detailed Description of One Embodiment of the Invention:

Increase current from background to peak quickly.

Maintain peak for duty cycle

Reduce current slowly from peak to background

Maintain background for period = 1/frequency

Typically a pulsed welding waveform is a square wave with fast transitions from background cur...