Mitsubishi Heavy Industries spherical stainless steel reactor vessel welding

The one heavy-section EB welding application Tom considers a real success. Two-inch-thick stainless steel spherical vessels, welded in a chamber the size of a two-story building, ~10 minutes per pass. Justified by hundreds-of-vessels production volume for a nuclear program. Stainless steels are also more weldable than carbon steels in heavy section.

Welding with lasers and electron beam — the theme is they're actually very different processes. You can get very thick sections in theory, but you have all kinds of big problems that people haven't really solved. So most laser and electron beam welding is not done over about a half an inch thick. People have been saying this is the solution to heavy-section welding, but no one's ever — well, the one application I know of, I think it was Mitsubishi Heavy Industries, had to make a bunch of spherical stainless steel vessels that were 2 inches thick. They built a vacuum chamber that was about two or three times the size of this room, and they could fit the whole vessel in. It's 2 inches thick stainless steel and they could go around it in about 10 minutes. They had to make hundreds of these for some nuclear reactor or nuclear physics experiment, so they could justify this very expensive vacuum chamber the size of a two-story building to weld these things. But that's sort of a specialized thing. And stainless steels are easier to weld than carbon steels in many ways due to their metallurgy.