Welding defects are something that manufacturers want to try to avoid at all costs. When a robotic welder produces defects during the welding process, it can cut down on the integrity of the weld, which can take away from the quality of the product. That is why it is important to understand how to troubleshoot your robotic system if you see welding defects.
Porosity is one of the most common welding defects. It can be caused by a shielding gas leak or a clogged welding gun nozzle. This can cause welds to be made from undercut or cold roll material, causing defects in the weld. There are many different steps you can run through to check for porosity issues and other welding defects in your robotic welding system:
Check for Shielding Gas Leaks and Flow – When checking for a shielding gas leak, use soap bubbles, and make sure all fittings are tight. The shielding gas flow should feel like it is coming out of the gun, but not enough to cause any turbulence or disruption.
Check for Spatter – A welding nozzle can get bogged down with spatter over time. Remove the weld nozzles from the robot system, inspect them, and clean any weld spatter before replacing them.
Replace Welding Tips and Liners Regularly – Welding contact tips should be replaced daily to ensure that the wire feed is smooth and consistent during each welding cycle. Welding liners need to be replaced weekly in shops that run three shifts per day.
Check Welding Wire – The welding wire should feel strong as it exits the welding gun. To prevent "bird nests", a tangle of wire that halts the wire from being fed, flip the drive roll and pull the wire back out of the gun. Then trim the tangled wire and re-thread it through the feeder and back to the gun.
Check Stick Out Height and Push Pull Angles – The typical stick out height for a welding robot, the distance from the end of the welding gun nozzle and tip to the weld joint, is 5/8 inches to 3/4 inches. Ensure that the measurement is correct, and check all the push pull angles of the system. Steel usually requires a drag angle of around 15 degrees, while aluminum requires a 15 degree lead angle to burn of oxides with the arc.
Once you have completed all of these steps, you should be able to correct the welding defects, like porosity, and return to a strong, durable welding application that will be high quality and consistent.