HIP FORMING OF SUPER DUPLEX ?
HIP FORMING OF SUPER DUPLEX ?
(OP)
Out of my comfort zone here ...
We have to engineer an offshore platform wellbay to accommodate around 1000 barG through to production and test manifolds. The production manifold will need to be approximately 500mm OD and around 100mm thickness. Around 10 branches of about 300mm OD and 70mm thickness will enter the manifold at around 1500mm spacing.The proposed material is super duplex stainless.
That's the easy bit. My question is ... how might we manufacture the manifold and branches ?
Hot isostatic pressing looks attractive because we could tailor the design to accommodate required pressure reinforcment, but ... it possible to use HIP with super duplex ?
If HIP is possible, are there significant welding problems with joining super duplex at this sort of thickness ?
Comments appreciated !
We have to engineer an offshore platform wellbay to accommodate around 1000 barG through to production and test manifolds. The production manifold will need to be approximately 500mm OD and around 100mm thickness. Around 10 branches of about 300mm OD and 70mm thickness will enter the manifold at around 1500mm spacing.The proposed material is super duplex stainless.
That's the easy bit. My question is ... how might we manufacture the manifold and branches ?
Hot isostatic pressing looks attractive because we could tailor the design to accommodate required pressure reinforcment, but ... it possible to use HIP with super duplex ?
If HIP is possible, are there significant welding problems with joining super duplex at this sort of thickness ?
Comments appreciated !





RE: HIP FORMING OF SUPER DUPLEX ?
I would suggest you contact Bodycote, as they have done this kind of thing quite often. Get them involved with the design phase as it will be much cheaper to have their input from the get-go.
Not sure if this is going subsea and connected to cathodic protection (can't tell from the description), but Hipped super duplex also allows for higher stresses without the risk of HISC.
RE: HIP FORMING OF SUPER DUPLEX ?
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: HIP FORMING OF SUPER DUPLEX ?
RE: HIP FORMING OF SUPER DUPLEX ?
Diffusion bonding is a "solid state" joining process, which means the resulting joint interface is of very high quality since the materials never undergo a phase change like that occurring with fusion welding processes. Since the materials being joined are never exposed to temperatures above their melting point, virtually any type of metal can be diffusion bonded, including super duplex stainless.
Hope that helps.
Terry
RE: HIP FORMING OF SUPER DUPLEX ?
RE: HIP FORMING OF SUPER DUPLEX ?
http://content.rolledalloys.com/dotAsset/9851d07e-...
RE: HIP FORMING OF SUPER DUPLEX ?
Thanks for posting that paper. I work in aerospace and when the term HIP is used it is generally associated with densification of structural castings. Powdered metal components are not common in aerospace, so I failed to consider that this process is indeed an application of HIP.
A couple years back, I looked at using HIP for densification of a large structural titanium investment casting. One of the issues that came up was finding a domestic vendor that had a HIP chamber of sufficient diameter to accommodate the part. The only US sources I could find with large HIP chambers were Howmet and PCC. Thus if the part is large or bulky, the number of parts the chamber can process in each cycle may be quite limited. It can cost upwards of $10K to run a single batch of parts through a large HIP chamber. I also found that access to these large HIP chambers was sometimes limited. So processing cost and access to a HIP facility are a couple more things that C2it may wish to consider in his trade study.