. Railway mechanical engineer . Fig. 1 —Radiograph of Steel Casting Showing a Blow Hole Belowthe Surface. The Circle Shows Where the Button Was Removed ever. The case now being described is a lung step in this di-rection. It is the object of this article to describe in detail whathas already been done in the way of an X-ray examination ofa certain steel casting of which suspicion had been aroused asto its homogeneity when in the machine shop. The original casting was 2^ in. thick and weighed about aton. When received at the Schenectady works of the GeneralElectric Company it had been machined
. Railway mechanical engineer . Fig. 1 —Radiograph of Steel Casting Showing a Blow Hole Belowthe Surface. The Circle Shows Where the Button Was Removed ever. The case now being described is a lung step in this di-rection. It is the object of this article to describe in detail whathas already been done in the way of an X-ray examination ofa certain steel casting of which suspicion had been aroused asto its homogeneity when in the machine shop. The original casting was 2^ in. thick and weighed about aton. When received at the Schenectady works of the GeneralElectric Company it had been machined down to desired shape and thickness. The amount still to be taken. Fig. 2—Machined Surfaces of thShown ButtorFig. from the faces was not more than % in., and in some placeswas only 1/16 in., but wiien this was removed it was found thatsome small imperfections had been cut into. These extendedover an-area about 5 in. long and lyz in. wide. The mechanicalilepartnienl at once chiseled away a part of the surface at thispoint, and then sent the casting to the research laboratory todetermine if, by means of an X-ray examination, it might be possible to reveal still other hidden blow holes or imperfections. .\ Coolidge tube especially made for use on high voltageswas set up in front of that part of the casting where the im-perfections had been found. An 8-in. by 10-in. Seed X-ray platewas mounted immediately behind the casting and the plate wasbacked by a large sheet of lead. The distance from the sourceof X-ray to the plate was 20 in. The tube was excited by aninduction coil with a mercury-turbine interrupter. The currenttlirough the tube was milli-
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
