The speaker is a 48-year-old White man with a college education from Greenfield, Wisconsin; he was recorded in 1968.
|Inf: Ok, we'll uh talk about the, uh, manufacture of large seamless rolled rings. Uh,
FW: Just like the ones you got out the front of the plant?Inf: That's a small seamless rolled ring.
FW: Oh, gee (laughing).Inf: Uh, we had best uh define the term large seamless rolled ring. Large, by arbitrary definition, would be anything over one hundred thousand pounds in weight. And, seamless is contrasted with various methods of making rings. Starting with, uh, the boiler shop concept of taking a strip of steel and rolling it from a flat length into a hoop, and
FW: Well you, how do you, join the ends on that then?Inf: And rivet the ends together. That's a boiler concept. And so it has a, a seam, a riveted seam. And, this is limited to very small cross-sections, maybe half-inch, maybe one inch maximum.
FW: And yeah, can you [?]Inf: Yeah, the thickness of the plate. Then there is another means of manufacture of a ring, which is called butt-welded. And this is a process whereby you take a strip of steel, either flat or contour cross-section, in the same manner that you roll a riveted ring, roll it into a hoop, and then, by applying a electrical potential across the two ends that are butting or adjacent to each other, you cause a arcing or sparking to occur. And this gradually heats the ends of the metal to the point that they become molten at the ends. And then, by pressure, you squeeze the two butted ends together, and this exudes all the oxides which are preventative towards welding. You extrude them out of the cross section and form a weld. A weld that is butted together, hence the term butt-weld.