Brazing 441SS to 441SS

[LargeNCharge86]

Hi all,
I apologize if this is the wrong subforum for this. We are brazing a 441SS bushing (4mm thick) to a 441SS pipe (1mm thick). Our company has not done brazing before and I'm having trouble finding the appropriate filler material and flux to put on the drawing. The only requirements we would have is that it needs to be able to withstand at least 650°C and support vibrations you'd expect to see in a vehicle's exhaust system.

Any suggestion on what to go with? Thanks!

 

[metengr]

At 650 deg C exposure temperature, braze metal will be ineffective. You need to consider autogenous welds using GTAW.

 

[LargeNCharge86]

I see a number of high temp filler materials rated for 800°C+ so I've got to believe it's possible to find something.

 

[metengr]

The problem is not the melting temperature but that the silver braze metal will creep and loose strength. If you decide to braze, go with the silver braze/flux for stainless steel.

 

[CWEng]

The only typical fillers that would come close are the BNi series. For ASME Section VIII, they are allowed to be used up to 650C without any special testing. However, some are a bit brittle, so I'm not sure about the vibration requirement.