When performing an arc welding application, you may notice a small concave dip in the weldment, usually at the end of a weld, no matter whether you are using manual or robotic welding. This is called a welding crater, and it is formed when liquid metal from the weld pool begins to cool. The weld metal contracts and solidifies, and a crater forms in areas of lower strength. The only way this can possibly be prevented is with a welding application that uses a very low current. The size of each crater relates directly to the welding current used.
So, what is the advantage of using robots when dealing with this arc welding phenomenon? The key to filling a crater with a robot is consistency in technique. Robots can be programmed to deposit consistent crater fills. This can be done either through ramping down the parameters in a controlled manner to fill in the crater, or to back-step the robotic welder. This is where the robot would reverse the direction of travel about one half inch while ramping down. Robots have the advantage over manual welding when it comes to filling in craters because they have a much higher level of accuracy and repeatability.
Accuracy and continuous filling are important when it comes to welding craters. Craters are not desirable because they can cause weld defects. If a crater is not properly filled, it can cause a complete failure of the weldment. Craters can detract from the strength of a weld. This can be critical for product assembly processes for many companies, especially assemblies in the aerospace and automotive industries.
If you would like to learn more about welding craters and how robotic automation can help to fix them, contact RobotWorx today at 740-251-4312.