Hot Pressure Welding (HPW)

Date 08-07-2003 14:38

Check the net, or get in touch with an organization like International Institute of Welding or The Navy Joining center or Edison Welding institute. Someone should know something.

Good luck

By flashburner1 (*)

Date 08-07-2003 21:22

Hot Pressure Welding is a solid state welding process, the oldest of which (I believe) is forge welding. This may help.
http://www.key-to-metals.com/PrintArticle.asp?ID=51
Brian

By colins

Date 08-07-2003 21:32

Great link Brian. Cool !

Colin : )

By scmait

Date 08-07-2003 21:50

I oversee HPW everyday. What would you like to know? Do you know the source of heat that is going to be use? I assume this is tubular product. What type of sizes are you going to be welding?

If you would like we can take this off line. Let me know.

SCMait

By flashburner1 (*)

Date 08-07-2003 22:37

Please,
If at all possible, please keep this online so the rest of us can learn about it also. While I consider myself proficient at what I do on a daily basis, learning about different applications and procedures that I am not familiar with is one of the main reasons that I have continued to visit this forum (and others also). I only stumbled on this one when trying to change my mailing address with the AWS - it led me to other forums that I think are valuable for the welding community as a whole.
Thank you,
Brian

By TimGary (****)

Date 08-07-2003 23:40

Yes. Please share with the rest of us!
Tim

By happybearwelder (*)

Date 08-08-2003 00:55

I have so many questions. First, this is tube, about 12 inch Dia. The wall is (just a guess) 3/8, and material is 300M. This is a new contractor taking over from the original. The heat source was Oxyacetylene, the new contractor wants to change to oxy-mapp gas. I don't know if it is in vaccuum chamber, inert-gas chamber or just inertgas flow. How am I doing for a newbe to the subject?
Other questions, how hot does this process need to get? How much pressure? Is the pressure generated by mechanical, air, or hydraulics? Does it matter?
That should be enough for one night. With all the interest, lets keep it on the web so we can all benifit. Thanks

By scmait

Date 08-08-2003 14:50

To lay all of the cards on the table...I work for the contractor I believe you are referring to. If you would like I could go over some of the highlights of the HPW process, however this is a proprietary process and I cannot divulge all the details of our process on this forum.

Or I will hold back my replies so you can get impartial input, if you would like.

By happybearwelder (*)

Date 08-11-2003 22:53

I sent you an email, did you get it?

By scmait

Date 08-12-2003 15:37

No I did not.

Sorry to those that want to learn about this process for taking this off line. The following are the very basic steps to the HPW process:

1. The parts are aligned in fixtures on a specially designed press and put under a load.
2. When loaded the 360 degree burner ring is ignited. The burner ring is supplied by Fuel and Oxygen.
3. The part is heated under load which will allow plastic deformation to occur. When the desired hot gather is reached the flame is extinguished and the weld is complete. Ultimately a diffusion bond is created.

By CHGuilford (****)

Date 08-12-2003 20:04

I'm not familiar with your process. What are the typical end uses of your weldments?

What sort of shapes can be welded together?
I assume pipe or round rods from your posting, but I was wondering if other shapes are welded with the process?

Advantages/ disadvantages?

It sounds like a variation of friction/stir welding?

You've stirred my curiousity and I hope you won't mind answering these questions. I did notice you said some of the process is proprietary so I certainly wouldn't want to encroach on that but I (and others I'm sure) would appreciate anything more that you can add.
Thank you,
Chet Guilford

By scmait

Date 08-13-2003 11:49

The typical end use is structural components for aerospace. Typically the shapes are tubular (many different sizes) however other shapes could be done with the proper equipment. The major advantage is that the strength of the weld is above 90% of parent material and that varying part configurations (asymmetric) can be joined. The biggest disadvantage is that it needs to be a very clean process. It is not friction or friction stir welding in that the parts or nothing else mechanically heats the parts.

Hope that helps,
SCMait

By CHGuilford (****)

Date 08-13-2003 16:11

Thanks for the info, SC.

Actually, when I asked about friction stir welding I was thinking more of the applications than the physical process. You provided what I wanted to know. Being in a structural steel fab shop, I doubt I will encounter either welding processes in the near future, but it is always interesting to see what the rest of the world is doing.

Chet Guilford

By jwright650 (*****)

Date 08-13-2003 16:48

Same here,
John Wright

By happybearwelder (*)

Date 08-14-2003 02:52

This has been a real education for me in more ways than one. I think I do have a fair understanding of how the precess actually works now. I have looked at some of the websites you fellas told me about and discovered a true wealth of information. I have also learned about these message boards. I think they are really super. I wish I had time to read them all. I will carfully read all the responces I have had to this, and any more that come in after this, add it to my own knowledge and I think I will be able to hold my own on this upcomming adventure. Thanks to all who answered.
The happybearwelder.