Hello, I mig welded a galvanized ring to a stainless pipe(304) using 309 wire and a tri-mix gas. The pipe was 12" o.d. and got a lot of cracks in the weld and inside the pipe in the stainless. The pipe I am making is blow pipe so Im concerned about leaks, but I can not figure out why it cracks. The fit up was good , no cross wind ect. I have tried 308 wire and get the same results. Any thought or comments is greatly appreciated. Thank you -Ed
Contamination from the zinc.
Dip the galvanized part is Muriatic (Hydrochloric ) acid as used for etching concrete. The acid will strip the zinc off in a flash, but make sure to do it outside and wear goggles. You can buy it by the gallon at Home Depot or Lowes.
After stripping, rinse in water with some baking soda dissolved in it. That will stop the acid.
i suggest the following , try to remove skin of galvanised portion and weld , if the zn is stripped by muriatic acid and welded if the outcome is same like cracks, pl inform what is the thickness of pipe and gi portion . what is the ambient temperature. cooling rates are high there is possibility of hard structures which leads to crack etc. vbravi
ded a galvanized ring to a stainless pipe(304) using 309
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.