welding 4140 to mild
welding 4140 to mild
(OP)
we are having a problem welding 4140 square bar to mild plate. we have tried 9598 and similar but with no success. the part will be in operation for a month or so then split. the 4140 is 2x2 sq.bar and a 5" x 1-1/4 flat bar is welded perpendicular to it so the 5" f.b. is welded to the 12' 4140 bar. If anyone has experiance making this stick please fill me in.





RE: welding 4140 to mild
What is the heat treatment condition of the 4140?
Use E7018 H4 weld rod or equivalent if using another welding process other than SMAW.
Apply a local preheat of 350 deg F. Depending on weld size, you might need to stress relieve.
RE: welding 4140 to mild
What is the load on the flat bar?
RE: welding 4140 to mild
RE: welding 4140 to mild
RE: welding 4140 to mild
If the electrode recommended above gives you any trouble you may want to try 312 SS rod, commonly used as a proprietary universal welding rod.