Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / Inspection & Qualification / vibration stress releaving
- - By browland (*) Date 08-21-2013 12:38
I have a customer that is asking me to use a vibration machine on a part while we weld it. He claims this is something that not only removes stress from the materials but also smoothes the welds out and lays in better. I have seen these used for post weld stress relief but not actually during welding. What is the code position on something like this and does it affect the welder qualifications, WPS, etc.?
Parent - - By 803056 (*****) Date 08-21-2013 14:00
I do not know of any welding standards that accept vibratory stress relief in lieu of thermal stress relief. Having said that, there is no better proof than to qualify the WPS using the procedure proposed for use in production.

I have used it with a level of success on aluminum weldments in preparation for machining. It is easier to hold the required tolerances once the parts had been vibratory stress relieved.

I did not have the same level of success when using the system on high strength low alloy steel.

I have read about vibrating the weld during the welding process. The vibrations agitate the weld pool and "allow" to atoms to align more easily. I have no first hand experience with vibrating during welding. Maybe someone here has actually used the process and can provide some experienced based feedback.

Best regards -Al
Parent - - By browland (*) Date 08-21-2013 18:01
Thanks for your response Al. This is a B&P for a large scale repair job on Carbon Steel (A36) and on Stainless (304), seperate weldments.. My thoughts were to perform a PQR and qualify a WPS using the vibration technique but I really didn't want to add that cost in the job. They are now seeing a large quantity of these weldments cracking due to thermal stresses and have decided to try the vibratory method to see if this helps. I have suggested that we run a few mockups of these parts and see how they hold up rather than assuming that it will work. I know that none of my in house WPSs are going to allow this.
Parent - - By welderbrent (*****) Date 08-21-2013 14:22
I am not familiar with this process myself but I notice a couple of things in Al's reply that cause me to really wonder:

1) What materials are we talking about?
2) What process in being used?
3) What code is being invoked?
4) Are there any PQR's and/or WPS's being referenced that are in question as to applicability? 
5) Are there requirements in the Job Specifications to utilize it?
6) Is the job already underway or just being bid and set up?

Have a Great Day,  Brent
Parent - - By browland (*) Date 08-21-2013 18:06
Brent,

We are making 2 different types of weldments, one is A36 and the others are 304SS.
The processes being used are both GMAW and GTAW depending on where on the weldments we are working.
Code is AWS D1.1 and AWS D1.6.
As of now, there are no referenced PQRs or WPSs
The customer has not produced any documention in regards to the job specifications, we are in the early stages of discussing this.
The job is now in B&P

Thanks, Bobby
Parent - - By Milton Gravitt (***) Date 08-21-2013 20:43
We have used it after welding but never during welding.

   M.G.
Parent - By welderbrent (*****) Date 08-21-2013 21:54
HIJACK:  Happy Birthday Milt!!  End HIJACK

Have a Great Day,  Brent
Parent - By G.S.Crisi (****) Date 08-21-2013 20:45
Al is right. Up to now, no American Code or Standard accept vibratory stress relief in lieu of thermal stress relief, which is the only one they accept. However, you can use vibratory stress relief for a "non code" application, of which there are many examples. 
Back in 2004, me and a former pupil of mine at the Engineering School of Mackenzie Presbyterian University in Sao Paulo, Brazil, presented a paper before the Brazilian Welding Conference organized by the Brazilian Welding Association. In the paper, we made a comparison between both methods: thermal and vibratory.
You can download the paper for free and written in English at www.stressreliefengr.com/news.html
Same as you, I've never seen vibratory stress relief being performed during welding, always after the weld is complete. If I were you, I'd carry out a test following your customer instructions; in other words, I'd made a test weld while vibrating it and see what happens.

Giovanni S. Crisi
Sao Paulo - Brazil
Parent - - By SCweld (*) Date 08-21-2013 21:06
I posted a link about the weld conditioning that was used at a company I worked for about 10 years ago.  I worked there for 10 years and we used the vibratory stress relief and weld conditioning extensively.  The gentleman mentioned in the article, Carl Smith, was the quality control manager and writes articles for "The Fabricator".  He is a retired professor from WVU and now works for the department of education in WV.  He would be a good contact for the vibratory weld conditioning.  I welded many jobs while being shook by the machine.  It was generally a mild shaking by made you cross-eyed at times.

http://weldingdesign.com/operations/high-power-stress-free-fabricating
Parent - - By 803056 (*****) Date 08-24-2013 19:02
Nice article.

I have a friend that did a research project for the company mentioned in the article. The purpose of the research was to determine what the vibratory stress relief did and how to predict the outcome. Their success at meeting the objective of the research was somewhat limited. The process works. It works good on some materials, but on other materials the benefit was not as pronounced. How or why it works was not conclusive.

As I noted, we used it with good success on aluminum weldments that need to be machined and tight tolerances maintained. The same could not be said for high strength steel. Some benefit resulted from the process, but it was not as pronounced as the results when stress relieving softer, more ductile, low strength materials.

I would like an opportunity to see the vibratory method applied to an in-process welding operation. I have heard good thing about the process, but I have no first hand experience with it. To endorse it or to condemn the process without actual experience would be short sighted.

Nothing ventured, nothing gained.

Best regards - Al
Parent - - By browland (*) Date 10-03-2013 19:48
Thanks for all the input guys. I will be running these coupons in probably 3 weeks and we will see what happens!
Parent - By Tyrone (***) Date 10-09-2013 10:48
Hey browland,
If the Customer wants to use vibration during welding, give him a quote with and without. 
One of the other departments here are looking into the benefits of using this process (about a year ago).  I'll try to dig up some info, but I think I remember the company that sells the equipment stated increased toughness due to reduced grain growth.

There shouldn't be any cracking with A36 & 304 (commonly welded).  I think something fundamentally is wrong.  Vibratory weld process may not address the root cause.

Tyrone
Parent - By Tyrone (***) Date 10-10-2013 11:38
The company that sells the equipment is called Meta-Lax. 
www.meta-lax.com 

Here's a tidbit from their website:
In addition to stress relieving, the patented Meta-Lax vibrations can be used during welding to prevent distortion, cracking and weld defects, as well as for welding faster.

Tyrone
Up Topic Welding Industry / Inspection & Qualification / vibration stress releaving

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill