Ford catalytic converter electron beam welding

Six out-of-vacuum EB welders at Ford sealing stainless-steel clamshell converters around ceramic filters. Speed ~60 cm/s. Used as the canonical automotive high-volume EB case. Maintenance nightmare on out-of-vacuum head (deferred to later lecture).

Electron beam is used in two industries basically, and laser to a certain extent. Lasers are used in a few more industries, but electron beam is used in two. Anybody know which ones? Ninety-eight percent of equipment is sold into two industries. Automotive, where you have tremendous volume. The catalytic converters a few years ago on Fords — you've got two pieces of stainless steel coming together like a clamshell, with your ceramic filter on the inside. That seam between the two pieces of stainless steel was electron beam welded. They had six electron beam welders at Ford sealing up these catalytic converters. It may have been 100 centimeters a second, but it was probably 60. Because they've got millions of these things to make, and you start figuring out how many shifts a year and how many inches of weld. If they did that in gas tungsten arc welding at 10 centimeters, they'd have to have 60 machines. With two or three centimeters they'd have to have two hundred machines. So the capital cost is in favor of the very high productivity electron beam welder.

Ford used six Westinghouse out-of-vacuum EB machines to weld stainless steel clamshells on catalytic converters — would have needed ~200 gas tungsten arc stations for equivalent throughput. Maintenance was a nightmare (the German-trained engineer who pitched it; the Ford plant manager who would "pull out a knife" at the mention of the technology). Ford eventually abandoned.

With electron beam or laser welding, you've got to have very high production volume to keep it busy, or a very high-value-added part. Electron beams and lasers are typically used in automotive, where you have thousands of feet of weld to make lots of parts. To weld the stainless steel clamshell on a catalytic converter, Ford one time went with out-of-vacuum electron beam. They needed six of them to take care of all the production for Ford's catalytic converters. If they had gone with gas tungsten arc welders at a much slower speed, they probably would have needed 200 arcs to do what six electron beam units could do, because of the difference in travel speed. So it's a question of the economics of the equipment.