Laser Cladding Info

[matkenmd]

I'm looking for input from people who use or have used laser cladding to reclaim or rebuild parts. I have a large high dollar 316L weldment with some sealing bores on it. During final machining or testing the tolerances were blown out of spec.

We want to add 316 or something even better perhaps to the bore. The finished product will be exposed to still sea water for years and must not develop a leak (extremely painfull high dollar downtime)

In the past we've declined to look into HVOF or other techniques without a mechanical or metallurgical bond. This laser cladding business is new to me, but seems promising. Can anyone tell me about their experience? Pitfalls to avoid, important tests to run during qualification phase, etc.?

Thansk.

 

[unclesyd]

What are the bore/s sizes and length?

Through or blind holes?

How much correction do you need to make?

 

[matkenmd]

"large" 11-13", blind sealing bores. The addition from current is usually under .010, but I understand we'll be making an undercut and building up so we don't cut through the fusion zone when finishing.

Hey, I was the one asking the questions, remember?

 

[MikeMet]

I have not seen laser cladding done on the ID only the OD. With that large a diameter, you can use old school fusion weld overlay. I can only assume you are worried about weld porosity or other internal defects that might effect the quality of the machined sealing surface. If done correctly by a company that knows their way around an arc, you can get a very high quality weld overlay. As for laser, it works well and I have not done any NDE or evaluation differently than one would use for fusion weld overlay. However, I admit I have only used for hardface overlay, not for corrosion resistance. You might consider a corrosion evaluation test, such as ASTM A262 on any weld overlay coupon. I would not think 316SS would be good choice for long term sea water exposure where a leak "must not" occur.