Annual'Meeting, May 2-3, IS
-i^cIüSE OF FAILÄr^ IN BOB^R PLATES«^/jfef_
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yPALTER ROSF^NIJAIN, D.Sc, F.R.S., and D. HANSON:MJ8c (Fkom tsIs Nationai, Physical Labobatoby.)
|_1-biri 3K3. met witE'
atjional cases of failures in boiler plates met witfi m five formed the subject of several papers and discus-ions before the Iron and Steel Institute in recent years.1 A mmber or such cases have been investigated by the authors, and it eems desirable to present an account of one which offers features of larticular importance which do not appear to have been previously ioticCd. These features are of special importance, because it may ie found that they afford a clue to the cause of failui e in other ases, particularly in boiler plates of the largest dimeijsicns.
The failure in question occurred in the last stage of the manu-icture of the plate. The size and dimensions of the plate are Iustrated in the diagram, Fig. 1. I he plate has a thickness
IINE Of FRACTURl
: If inches and measures 4 feet 4 inches in width by 11 feet in ngth. It was manufactured under a stringent specification, ut cracked during the straightening of the edges after the ending operations had been completed. Inquiry showed that ie bending operations had been carried out in stages in the »ld, the plate being subjected to intermediate annealings be-reen the various stages. The position of the crack which rmed in the plate is indicated in the diagram, Fig. 1. The material of the plate was first submittal to chemical
1 Houghton, Journal of the Iron mid StteJ Iwstittite, 1914, No. I. p. 266. Wolff, "bid„ 7, No. II. p. 137.