Wear Resistant Weld Overlay
Wear Resistant Weld Overlay
(OP)
We have an opportunity to take on a project that requires weld overlay of a part that requires a wear resistant overlay. Basically, the part (4130) has a rectangular track in which a roller bearing rides back and forth (we will overlay the track). I've done a little research, and noticed that Inconel 625 is sometimes used to hardface forging dies. We are comfortable with welding 625, so it would be nice if we could use it instead of experimenting with the many other hardfacing alloys out there.
Any opinions on using 625 as a wear resistant overlay for this metal to metal scenario?
Any opinions on using 625 as a wear resistant overlay for this metal to metal scenario?





RE: Wear Resistant Weld Overlay
Is there a reason that these tracks are not nitrided or treated with some other diffusion process?
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P.E. Metallurgy, Plymouth Tube
RE: Wear Resistant Weld Overlay
Have you considered machining the track in the 4130 part slightly oversize, hardening the track surface using gas nitride, and installing a new bearing with a slightly larger OD to match?
RE: Wear Resistant Weld Overlay
RE: Wear Resistant Weld Overlay
RE: Wear Resistant Weld Overlay
There isn't a specific reason why these parts weren't nitrided to begin with. The parts (pipe tongs for drilling) we are looking at are 25 years old with some wear after many years of use. Customer wants to refurbish them. So, we could overlay with carbon steel,PWHT, machine to spec and then nitride. Would there be considerable dimensional change after nitriding? Or would it be best to have the machine shop perform a slight skim cut after nitridng?
RE: Wear Resistant Weld Overlay
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P.E. Metallurgy, Plymouth Tube
RE: Wear Resistant Weld Overlay
"Would there be considerable dimensional change after nitriding?" The gas nitriding is performed at temps below 1100degF, and since no quench is required there should be little distortion. There will be an extremely small dimensional change on the nitrided surfaces, but probably not enough to require finish grinding for your application.
With either nitriding or weld overlay, you will need to do some machining of the part. But to me it seems like less effort to machine the track groove oversize, nitride the part, and use an oversized roller follower.
Of course if the track groove will require periodic rework, you might consider modifying the part to accept a bolt-in track insert. This way it can be repaired quickly and likely at lower cost. Downtime is usually a major concern with machinery repairs, so this approach might be attractive to the equipment operator.