Help welding cast iron

Mike

Link

Above are two links to former posts on this MB that I think will help you with welding cast iron. For this type of repair which is more replacing missing metal as opposed to repairing a break that extends through the metal you're getting off easier.

You need to control the heating and cooling of the piece so you don't end up breaking it from stress. Based on my past eperience with similar items, Clean as normal with grinder/wire brush to remove any slag and then a chemical clean to remove the oils. You should heat the part completely to around 400F before welding. For this you can use about any type of cast iron electrode because you don't have to machine it at all. A high nickle will probably be best but I'll leave that answer for Steve from US Alloys.

Run short stiches of weld only 1/2" - 3/4" long at a time opposite each other as not get a big HAZ (heat effected zone), use the lowest amperage setting possible so that the rod barely maintains an arc. Immediately following you stopping the bead, use either a chipping hammer with the pointed end or a needle gun to peen the weld and to both sides of it. Don't beat the piece to death but don't go too light either. I prefer using a needle gun running around 65 psig of air, this is fastest and maintains a steady peen action. Try to maintain the steady 400F all the time on the part during the welding process. Once done with the welding, cool the part slowly by reducing the pre-heat a little at a time and keep the part out of a draft or other ambient or compressed air flows.

Using the small stiches, you'll not only keep the heat down but have less of a chance of warping the part too. Good luck!

The 110V wire welder is too small for this job. You will have to go with stick or powder. An alloy high in Ni content will be most machinable.

I am not familiar enough with the part you mention to visualize it. But, if you do need to weld that groove to restore part integrity and it needs to be entirely remachined inside (due to shrinkage) to get the original size back, the lost dimension could be easily restored by one of the metallising processes. Choosing the proper metallising process will not put excess heat into the part. Part temp can be held to around 500�F wih the cold spray powder torch and to less than 200�F with the twin wire arc process. Keep in mind that these deposits are coatings and are not designed to add integrity to the part in as much as a joining process is concerned. These deposits are only used to take up space or provide corrosion or wear protection.