7018 Rod...on Spring Steel

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how will this work? (im welding leaf springs...i know what you're thinking...why? long story)i normally use 309 stainless......i dont want them to come apart....i often plug weld them
Reply:I've attempted 7018 on spring steel several times in the past in a tight to get something back to the shop or to get thru a day or two.  Never seen it last as a permanent repair regardless of what it was welded with.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Being a highly hardenable steel, a weld on a spring without preheat and postheat will produce untempered martensite in the HAZ which is so hard and brittle the spring will crack at that location.  I'm not sure of the proper pre/post heat treatment, or if it is really effective in welding a spring, but if you have to weld it, this is your best shot.And as you mentioned, 309 SS is could be a better choice than 7018, depending on if the weld needs to be springy or not, since the 309 is ductile, it will absorb some of the applied stress and help prevent failure in the HAZ.Probably the best way would be to anneal the spring, weld with a high strength rod, maybe 8018, 9018, 11018 (not sure whats available or appropriate to match the spring), preheat/postheat, and re-heat treat, that way the weld chemistry better matches the base metal and the whole weldment has uniform properties.
Reply:Theres a better way, get some square tube which the ID matches the outside width of your springs.  Cut a ~1" piece off and cut the top off so it looks like |_|.  Then just cut another piece to sit on top of the spring, clamp it together and weld.  If you want you can drill a hole and weld a nut thru the top for a set screw but its not needed if you clamp it tight.I tried welding mine before to keep em together in a pinch and it doesnt work, and Ive never heard of it being done successfully.Have we all gone mad?
Reply:I tried welding mine before to keep em together in a pinch and it doesnt work, and Ive never heard of it being done successfully.
Reply:well i did it....do i like it? ehhhhh.....id rather use the 309.....im happy with the results but like the 309 for plug welding....its just smoother......the springs dont need to be 'springy'ive repaired springs like 88 said....when they have to be springy....i did use the torches after about 2 minutes to heat the stuff up.....kinda figured it out on my own it needed to be 'warm'.....i build demolition derby cars.....and build solid-*** 9 leaf packs with a 1" stairstepi dont weld them front to back end to end and kinda i have to hide what i do....under that stress that they go through, frames bending and the like.....ive never once broke a weld or had the springs come apart.....im doing something right.....everyone has always said and told me, from people that have been welding for 30 years right down to the spring shop.....u cant do it.....wrong =)i was curious about the 7018 cause...its cheap lol....and i know its a good rod on metals that need to last.....stainless rod is getting expensive (i remember paying $5 lb for it) and i wanted to try something
Reply:We cant see anything!