Weld overlaid by flux wire process using a wire TP430.
Weld overlaid by flux wire process using a wire TP430.
(OP)
We have an exchanger shell plate A335 P12 15mm thick that was internally weld overlaid by flux wire process using a wire TP430.
After weld the clad deposition of TP 430, the dye penetrant inspection revealed that TP430 weld overlay was found with lots of pores and cracks.
What went wrong in this welding procedure?
Wrong filler wire?
Lack of PWHT?
Will it be beneficial to use of TP410S filler metal instead of TP430?
Thanks
luis





RE: Weld overlaid by flux wire process using a wire TP430.
It looks like from your OP you may have missed one critical step for a dissimilar metal weld - where is 309 stainless steel for the 1st pass prior to depositing the 430 wire? You cannot deposit 430 stainless steel filler metal directly on carbon or low alloy steel substrates because of dilution concerns. The cracks are probably the result of an intermediate chromium-containing martensite that has little ductility.
RE: Weld overlaid by flux wire process using a wire TP430.
RE: Weld overlaid by flux wire process using a wire TP430.
Thanks for your empathy.
luis
RE: Weld overlaid by flux wire process using a wire TP430.
A 309 first layer and 439 (the stabilized grade) for the over lay would be my thought.
They probably tired to build it all in one pass. The ended up with a high Cr martensitic weld that has no chance of not cracking.
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Plymouth Tube
RE: Weld overlaid by flux wire process using a wire TP430.
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Weld overlaid by flux wire process using a wire TP430.
The version of API 582 that I have doesn't list 430 as a final overlay option without the approval of the end user (B1.9).
RE: Weld overlaid by flux wire process using a wire TP430.
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Weld overlaid by flux wire process using a wire TP430.
RE: Weld overlaid by flux wire process using a wire TP430.
Because it exhibits lower weldability in relation to other stabilized grades of ferritic stainless steels.
The 309 or Ni-base filler metals will work for buttering. The reason for the cracking in the OP is that 430 stainless was deposited directly on carbon steel or low alloy steel base metal with no buffer layer. This resulted in ferrite and most likely an interconnecting network of untempered martensite and subsequent cracking.
RE: Weld overlaid by flux wire process using a wire TP430.
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04