Alloy 188 fabrication

[will123123]

I am looking to design a part that will be manufactured from cobalt alloy 188 (ie Haynes 188, Udimet 188..). This will be operated at temperatures between 700 and 1050°C. Would the standard final heat treatment of holding at 1175°C for 30minutes followed by fast cool be appropriate for the intention of stress relieving the welds and maximising strength and durability at those temperatures? Has anyone had experience with using the material!

 

[TVP]

Have you reviewed the recommendations from Haynes:

http://www.haynesintl.com/pdf/h3159.pdf

 

[will123123]

TVP,

No I had not read that reference thank you - it has given some food thought. There will be some machined components welded on to formed sheet, which in turn will not be subject to large deformations, so based on the document from Haynes a full solution treatment may not be the best thing due to the potential of excessive grain growth.

People's thoughts would be appreciated!

 

[EdStainless]

What is the thickness of the material and welds?
If this is thin I would probably go with 1170-1175 for 5-10 min and force air cool.

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Plymouth Tube

 

[metengr]

Talk to Haynes directly. I know at least one of their staff metallurgists and they know their product line.

 

[will123123]

The part is a fabricated tube with a wall thickness of less than 1mm, although some of the machined parts that have been welded on have a section thickness of around 5mm.