Stud welding

Date 12-05-2005 21:22

Does anyone know why AWS requires 5/32" or 3/16" electrode size for welding studs over 7/16". See AWS D1.1 7.5.5.6 (page 255 of the 2002 code book). I would like to know the logic behind this requirment.
Thanks
Jim Hughes

By waynekoe (**)

Date 12-05-2005 21:29

'tis my understanding that the larger the rod, the greater the heat, the more heat, the longer it takes to cool, which leads to the more hydrogen is able to difuse from all the materials. Of coarse, I could be mistaken. Its happened once before. Wayne

By jwright650 (*****)

Date 12-05-2005 21:41

Table 7.2 may be an indication, look at the fillet sizes for 7/16 dia and up.
Notice in C7.5.5 ......"The electrode diameter is specified to help ensure that minumum heat input is provided in conjuction with the applicable preheat requirements of Table 3.2."
John Wright

By waynekoe (**)

Date 12-05-2005 22:56

Well, what do ya know. Again, A new wrinkle in my brain.

By Jim Hughes (***)

Date 12-05-2005 23:25

Thanks John,
we give coins on this project for good work. I owe you a coin! Your reply make sense. But when you have a welder having to weld up a stud on to an inbed and he can barely see the stud much less get a 5/32" (bat) electrode down where he needs to weld, it's hard to explain to him why he needs to use that size electrode. But now I can show him in the commentary section.
Thanks
Jim