I'm making some large parts out of 17-4ph HH1150. The HH1150 is the heat treat designation which results in the material being pretty soft. That is, soft for 17-4. Well, a drilled hole went oversize and now it's too large for the 1/8 pipe threads that need to go in. So, I can either weld the hole and re-drill and tap, or machine oversize and thread in a plug that is already tapped for 1/8 pipe, or throw away a $400.00 part. I think I can get away with putting in a plug with 1-20 threads on the OD and 1/8-27 through and then welding the perimeter of the plug to retain and seal it. It needs to hold 15,000 psi. I would rather fill the hole with weld though and just re-machine it. What I don't know is if I weld it what the hardness of the weld and the HAZ will be. If the 17-4 is held at 950 degrees for an appreciable length of time it will reach maximum hardness. But if I use 308 filler I don't know what the resulting alloy will do. Any suggestions? Before I do anything to the part the customer will be notified and will need to give me the OK. And he will be doing the pressure testing. I have looked on line for info about welding 17-4 and it is possible but I have not found any real world examples. Thanks, Eric
- posted
12 years ago