. Railway mechanical engineer . Iron, Continued By Alfred S. Kinsey* AFTER making welds in cast iron, as described in thisarticle last month, the next step is to determine if thewelds have been made as nearly j>erfect as is especially important in some cases where the weldsare subjected to more or less severe stress in service. 14. Examination of Weld.—.\fter a cast iron weld iscompleted and cold, if it is of much importance it shouldbe examined for porousness and other defects. It shouldnot be assumed that because the joint lias been reinforcedall has been done that is pwDssi
. Railway mechanical engineer . Iron, Continued By Alfred S. Kinsey* AFTER making welds in cast iron, as described in thisarticle last month, the next step is to determine if thewelds have been made as nearly j>erfect as is especially important in some cases where the weldsare subjected to more or less severe stress in service. 14. Examination of Weld.—.\fter a cast iron weld iscompleted and cold, if it is of much importance it shouldbe examined for porousness and other defects. It shouldnot be assumed that because the joint lias been reinforcedall has been done that is pwDssible to insure a good strongweld. After the metal is cold the surface of the weld mightbe cliipped with an air chisel or hand chisel sufficiently deepto remove the thin harder surface here and there over theweld. This will lay bare the upper metal of the weld andexpose any porousness or lilow-holes which may have devel-oped. If such defects are found they may be due to thefollowing: (a) Too lilxral use of flux, (b) Not enough. Fig. 1—A Typical Iron Casting Welded by the Oxyacetylene Torch I>uddling of the molten metal with thu wilding roil, (c)Improper adjustment of the torch tlame. (d) Allowing theweld to cool too quickly. A good wehier can avoid all ofthese weaknesses. If the weld contains blow-holes or showsgeneral porousness, the surface should be chipped deeperuntil gtxxl homogeneous metal is found, and then the jointshould be rewelded. If the defeds ap|K-ar to go entirelythrough the joint the whole weld should be (hi|)|H-d out, andthe jolj done over with greater care, liie weld should alsol>e examined for small shrinkage cracks l)oth in the jointand particularly adjacent to the weld on both sides. Thesecracks may not Ik; due to welding at all. They may hav(-Ijeen caused at the foundry when the casting was math-, byimproper Cfxjling, ])r venting of the sand mold, improperramming of the sand, poor mixing of the metal in the cu[>ola,improper balanc ing of the che
Size: 1841px × 1357px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
