|"WHEN EB WELDING, HOW DO YOU DETERMINE THE BEAM PARAMETERS FOR WORK PIECES AND THE RELATIONSHIP BETWEEN BEAM PARAMETERS SUCH AS THE RADIUS OF THE BEAM ON THE SURFACE AND THE DEPTH OF PENETRATION?"
You may find that the American Welding Society’s (AWS) C7.1 Recommended Practices for Electron Beam Welding is one resource that can be particularly helpful for your benchmark parameters. Typically when developing parameters for a new weld, you will start off by welding a sample test piece composed of similar materials benchmarking your weld with sample settings. You can adjust the weld width at the top to be as narrow as possible by adjusting the beam focus, and your weld at the bottom will always be narrower than at the top. Once your sample has cooled, you will need to cross section the weld joint and examine the weld characteristics from your first attempt adjusting the beam parameters accordingly. Repeat this process until you’ve achieved acceptable results.
However, depending on the potential cost of replacing a ruined part or obtaining exotic materials for sample welds, trial and error development may not be a viable option. In this case, you could contact an experienced EB Welding Job Shop to do the weld development for you ensuring that it is done correctly and at the same time you will gain the knowledge of how to weld this part yourself in the future.