What Is Electron Beam Welding?
Why Electron Beam Welding?
Weldments can be small with diameters less than 0.10 inch to larger diameters and lengths to 12+ feet, weighing up to 150 pounds. Weldment joints depths can be from less than 0.01 inch to 0.40+ inch.
MATERIALS WELDABLE BY THE ELECTRON BEAM PROCESS
300 series stainless steel, Inconel alloys, Hastelloy, Waspaloy, Nitronic, MP-35N,15-7PH, 17 4PH, 17-7PH, Titanium alloys, Monel, and with lesser weld penetrations copper and aluminum.
Beamalloy maintains all customer proprietary information – drawings, specifications, manufacturing procedures, etc. - in strictest confidence for a minimum period of ten years. The same confidentially applies when Beamalloy receives proprietary information as a subcontractor from the customer’s primary contractor.
Beamalloy maintains Beamalloy’s in-house developed manufacturing methods for the customer - weld procedures, special fixtures, drawings, etc. - in strictest confidence for a minimum period of ten years.
One exception to the above is when the service of a subcontractor is required for Beamalloy to perform the requirements of the job, in which case the subcontractor is given only the information to perform his operation, and then only with the written permission of Beamalloy’s customer.
CHARACTERICS OF ELECTRON BEAM WELDING
• Edge preparation is not required, regardless of the thickness of the workpiece. Filler material is not required.
• The high welding speed results in narrow welds and heat affected zones with little distortion of the workpiece. Total heat input to the workpiece is low.
• The inertia free oscillation of the electron beam makes it possible to join materials otherwise considered unsuitable for welding.
• The welding is carried out under vacuum; no shielding gasses or fluxes are required to protect the weld pool from oxidation. Post weld clean-up is not required.
• Computer monitoring and control of the electrical and mechanical welding parameters is possible.
• The welding parameters, and thus the quality of the welds produced, are highly reproducible and consistent.
BEAMALLOY’S CONTROLLABILITY FOR EXCELLENT REPEATABLE WELDS
• Automatic Beam Focus.
This feature automatically produces an optimally focused beam for variable beam intensities.
• Automatic Beam Intensity.
The Programmable Beam Intensity control (PBI) during the weld sequence:
(1) accommodates joints with variable depths.
(2) compensates for the increasing depth of the weld toward the latter part of the weld sequence, as the weldment temperature increases.
• Programmable Beam Shape and Beam Width.
This feature provides for a tailored beam width and a power distribution of the beam intensity across the weld joint, optimizing conventional welds as well as unconventional welds of thinner materials to thicker materials; for example, welds of a tube to a tapered boss, bellows to a ring or tube.
• Automatic seam tracking.
This feature automatically and accurately tracks a circular weld joint, regardless of the concentricity of the joint.
• Programmable rotational speed control and automatic beam synchronization.
All rotating fixtures have integrated optical tachometers. A Digitally Programmed Controller provides for accurate and repeatable rotational speeds and beam synchronization.
Beamalloy has in-house machine tools capable of producing specialized tooling.
These are: 17-inch x 60-inch CNC lathe.
15-inch x 20-inch x 12-inch CNC milling machine.
13-inch x 24-inch Clausing manual lathe, with numerical X-Z readout.
9-inch x 48-inch Bridgeport manual mill, with numerical X-Y-Z readout.
10-inch x 16-inch DoAll Band saw.
All machine tools are in excellent condition.
QUALITY CONTROL DOCUMENTATION
Each individual weld of a weldment is assigned a Weld Procedure. This Weld Procedure lists the parameters used to produce that individual weld.
Weld Procedures are stored by both electronic and hard copy methods. Weld Procedures are cross referenced to the customer and to the corresponding drawing number. The Weld Procedure Number, Revision Level, and the Operator Code appear on the customer’s Shipper and Invoice.
All weld procedures are kept on file indefinitely.
Beamalloy has in-house capability to produce metallurgical weld samples – cutting, polishing, and etching – complete with digital microphotography. Photographs of sectioned sample welds can be supplied to the customer with weld certifications.
Accurate weld measuring is done with Beamalloy’s microscope equipped with a micrometer X-Y stage.
Beamalloy uses a set of precision rollers with micrometer readout for testing the straightness of cylindrical and tubular weldments. Tests can be made before and after welding to determine the effects of the weld. A calibration bar is part of the testing equipment.
Helium leak testing can be provided by Beamalloy for verifying the integrity of Beamalloy’s electron beam welds. Beamalloy’s very stable and very sensitive helium leak testing equipment can detect leak rates in the 10^-3 to 10^-10 atm cc/sec ranges. Beamalloy maintains Calibrated Leak Standards which are routinely used to verify the calibration of Beamalloy’s helium leak testing equipment.
Beamalloy maintains equipment calibration standards, traceable to NIST.
STANDARDS AND DOCUMENTS ON FILE
Beamalloy maintains the following publication standards on file:
AWS Materials and Applications, Part 1 (Vol. 3).
AWS Materials and Applications, Part 2 (Vol. 4).
ASM Metals Handbook, 8th Edition
Properties and Selection of Metals.
ASTM A380 / A380M-17
Standard Practice for Cleaning, De-scaling, and Passivation of Stainless Steel, Parts, Equipment, and systems.
AWS C7.1M / C7.1: 2013
Recommended Practices for Electron Beam Welding and Processes.
ILNAS-EN, ISO 2085: 2018
Non-destructive – Leak testing – Tracer gas method (ISO 20485 – 2017).
CONVENTIONAL WELD VS ELECTRON BEAM WELD