Canadian foundryman (1921) . twas not of a severe enough nature to bea true measure of the quality of malle-able iron. About this time, also, demands werebeing made on the industry for a pro- duct that would consistently pass atest based on the tensile strength andelongation. The standard specificationfor malleable iron of the AmericanSociety for testing materials then calledfor a tensile strength of 38,000 poundsper square inch and an elongation of5 per cent, in 2 inches. This, it will beagreed, did not put the material on avery high plane and the Associationbent its energies toward developin
Canadian foundryman (1921) . twas not of a severe enough nature to bea true measure of the quality of malle-able iron. About this time, also, demands werebeing made on the industry for a pro- duct that would consistently pass atest based on the tensile strength andelongation. The standard specificationfor malleable iron of the AmericanSociety for testing materials then calledfor a tensile strength of 38,000 poundsper square inch and an elongation of5 per cent, in 2 inches. This, it will beagreed, did not put the material on avery high plane and the Associationbent its energies toward developing aproduct that would easily surpassthese figures. Standard five-eighths-inch test barswere made daily by each member fromhis regular heats and submitted to themetallurgist for test. Exhaustive in-vestigations of the failures were carriedon, ovens and furnaces were redesigned,temperature control apparatus was in-stalled and finally the Association wasable again to report progress. Carefulrecords of these tests have been kept. FIG. 3 —TEST WEDGE AFTER RECEIVINGSUFFICIENT BLOWS TO BREAK IT, THUSDEMONSTRATING WHAT ITS REALSTRENGTH IS. and the improvement made can beshown by the following figures. In November, 1915, of all the barssubmitted for test per cent, failedto reach 40,000 pounds per square inch,tensile, while only per cent, of allthe bars exceeded 52,000 pounds. InDecember, 1918, the latest figuresavailable at this writing, only twenty-five hundredths of one per cent fellbelow 40,000 pounds, per cent ex-ceeded 44,000 pounds and 39 per cent,tested over 52,000 pounds per squareinch, with an average elongation per cent, in two inches. Theselast figures give the result of testsmade in 1257 bars. To further illustrate what is possibleof accomplishment, we give below therecord of a run of 24 successive heats. First Lot—Twelve BarsAverage ultimate strength, .58,493Average elongation, per cent .... Second Lot—Six BarsAverage ultimate stren
Size: 1373px × 1819px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectfoundri, bookyear1921
