Weld Repair of Cast Iron
Weld Repair of Cast Iron
(OP)
We have a customer requesting we attempt weld repair of some cracks in a slag crucible. It's cast iron ~ 3" thick. I had PMI done reporting the following, C > 3.50%, P .052, S .062, Mn .066, Si 1.5, Cu .23. I'm thinking we need to pass. Anybody have any thoughts?





RE: Weld Repair of Cast Iron
Are any of these cracks through-wall? I would probably pass on any weld repairs because of the service duty and risk of developing more cracks.
RE: Weld Repair of Cast Iron
Yes, there are some cracks that are through the entire wall thickness. My thinking is that any attempt to repair a material such as this is likely to be fraught with problems. I've recommended to the owner that we steer clear of this one, but, I may be over ruled.
RE: Weld Repair of Cast Iron
Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.
Lower Alabama SolidWorks Users Group
Magnitude The Finite Element Analysis Magazine for the Engineering Community
RE: Weld Repair of Cast Iron
RE: Weld Repair of Cast Iron
it was 24" thick and 24" long weld.
the part was furnace brazed.
I am not sure if this material would meet your temperature requirements, the repair was stronger than the original cast iron, but weld metal may have a melting point lower than what you are doing.
Lock 'n Stitch is the company with their main office in California, but they travel all over the world repairing and welding castion that is not, for one reason or another, not economically of physically able to be shipped
RE: Weld Repair of Cast Iron
The name of the company is Engineered Casting Repair Services, Inc./METALOCK Corp.
http://www.casting-repairs.com/services.htm
Tommy's a good guy. Give him a call...he may either be interested in the work if you aren't, or he may be able to give you a good idea on the troubles that you might run in to.
RE: Weld Repair of Cast Iron
If worst comes to worst you might try to find someone who still does thermite welding of CI. This was a common way to repair slag transfer cars at one time.
Also depending on the size of you CI vessel you might want to talk to the people who do flood welding.
Also if you could heat/preheat the casting to 1325F you stand an excellent chance that the repair will be successful. This takes someone well versed in the art of welding cast iron.
RE: Weld Repair of Cast Iron
When preparing the damaged area, use arc gassing in order to obtain a good welding geometry.
This method will prevent carbon from being smeared on the surface and therefore reduce the risk of cracking when weld material is applied.
If it is possible, try to use an elevated work temperature, say 300 degrees Centigrade, during the welding process – followed by at slow cooling rate.
The filler material should be a Nickel-base (from 55% Ni and up).
After each bead, hammer on the weld in order to release tensions.
Repeat until finished.
There might be a different colour in the repaired are.
Do not forget to get customer acceptance in advance and notify machining company about different material data if turning or milling is used.
I have used this method when I worked in European foundries.