tig process

By TAMPALUIS (**)

Date 12-21-2006 16:24

I forgot to say that the cretification process is based on AWS D17.1: 2001, for aircraft applications

By amr Date 01-22-2007 19:22 Edited 01-22-2007 19:24

plz if any one have D17.1 i need it very much if any one can send it to me i will be glad e-mail: amr_aerospatial_2005@yahoo.com

By Lawrence (*****)

Date 01-22-2007 19:44

http://engineers.ihs.com/collections/abstracts/aws-d171.htm

By Lawrence (*****)

Date 12-21-2006 16:37 Edited 12-21-2006 17:46

Tamp

Thats alot of questions.

1. "cetified to which code/standard?   The code standard will dictate the importance of many of the variables and how/if they must be recorded.

(Edit. Ok D17) a nice standard indeed. One that allows production mock ups for procedure qualifications in many cases. (this is especially important in repair situations)

1,a It is important that you have a copy of the standard and refer to section:
4.4 Welding Procedure Qualification
4.4.1 Written Welding Procedure (if you defer to B2.1 Flux would be essensial and recorded)
4.4.2 Procedure Qualification
4.4.3 Method of Procedure Qualification
4.4.4 Alternate Methods of Procedure Qualification
1.b Important to note that not only all welders but *all* procedures for class A and B welds must be qualified by testing.

2. Flux is almost never used with Aluminum or Titanium GTAW

3. There are fluxes that are used (rarely) to increase pentetration and travel speed in some stainless/nickel alloys, there is plenty of data available.
3.a edit... Also solar flux may sometimes be used for field repairs where proper argon purge is not possible.
Solar flux is not an optimal fabrication choice, and scheduled, recurring post weld inspections are often
incorperated into on wing repairs involving solar flux. My personal view is that Solar Flux is unviable for
original fabrication or Depot level repairs. Further that welders who are not using Solar Flux regularly
should make mock up repairs on a semi annual basis. (the stuff is that hard to work with)

It sounds like you have a very big job ahead of you.

Overseas Aerospace repair depot? Just a guess.   If you are doing depot level repairs than you might be able to gain access to the standard practice manuals of the original engine/componant manufacturers. This will be a big help in preparing procedures.

I can remember having to jump through many hoops to satisfy the engineering folks at CFMI, while both Pratt and GE proved to be very helpful in repair development, especially when we shared our own engineering improvements to their processes.

By Lawrence (*****)

Date 12-21-2006 17:13

Here is some valuable data on work done by many folks and collected by FAA on Inco 718 behavior.

Special emphasis in turban componants repair should always be placed both annealing and post weld stress relief cycles.

Lots of data on cyclic influence on welds and cracks.

And good data on *rejuvination* of inco 718 castings. Not a perfect process but those compressors are not cheap so what can be done to extend their life span is worth the investment.

http://www.tc.faa.gov/its/worldpac/techrpt/ar97-88.pdf

By TAMPALUIS (**)

Date 12-21-2006 19:21

lawrence, thanks a lot, that is an excellent information

By TAMPALUIS (**)

Date 12-27-2006 21:02

The filler materials that I found for our base metals are:
- ER 4043 (6061)
- 6-4 (Ti-6Al-4V)
- inconel 718 (inconel 718)
are these materials correct?
And for the other stainless steel, I didn't find theier filler metals
Can anyone help me with that?

And I have another question, which are the storage conditions for these filler metals?

thanks

By Lawrence (*****)

Date 12-28-2006 04:24

Tam

First of all.

This forum is not the place to find technical guidance as specific as you are asking. Would you want the person making welding decisions for aircraft your children are flying on to be getting his filler metal selections from an internet chat room?

Those answers are found in the code you say you are adhering to. Get a copy.

It sounds like you could really use an expert consultant to help you get started.

By TAMPALUIS (**)

Date 12-28-2006 14:20

lawrence,
yes, I understand your point. but I am asking for help about where I could find the information, because I am new in this topic and the code that I am using is no speciifc, and is hard to me to get the copy of other codes.

By jon20013 (*****)

Date 01-22-2007 20:44

Lawrence, thanks so much for making that point. People tend to forget, just because we are all "experts" in a given path of our field, the Forum is not intended, and in fact is improper to be considered as a vehicle for gaining for in-depth knowledge.

By Lawrence (*****)

Date 01-22-2007 21:16 Edited 01-22-2007 21:23

Jon,

Sometimes I just don't know what to think.

It scares the dickens out of me when I think about Americas major airlines farming out their jet engines or engine componants to folks who don't even have the most basic idea of how to refurbish them. I'm no Xenophobe, but rather a free market Capitalist, and if a foreign competitor can do better work at a lower cost than they should win.

But some of the examples I have seen of over seas, and even some U.S. repair shops that are taking in the farmed out work of the Major Airlines is just stunning.

Pratt, GE, CFMI, Rolls Royce, Allison, You name the jet engine manufacturer... They all have standard practice manuals with guidelines for alloy/filler matching tables, surface prep, annealing, post weld stress relief, materials handling, surface temper etching for HSS, pre/post heat... you name it. How does anybody win repair bids for 5 million dollar jet engines without some mechanisim to get the correct repair specifications?

The makers also have repair specifications that are specific down to part number families that provide repairable limits and specific step by step procedures for every componant that a vendor authorizes to be repaired... And the repair procedures are often quite different from fabrication guidelines.... a very important distinction!

This stuff is complicated! There are no simple answers. A full blown quality program is essencial.

It's not my intent to be stingy with data but if a facility does not have all the data tools I have mentioned above, along with a qualified engineering staff to make process/welding decisions, they don't have any business touching those componants.

Ok my pulse is starting to even out.... more later

By jon20013 (*****)

Date 01-22-2007 21:22

Lawrence; I used to enjoy flying (a very long time ago) now, with so many miles under my belt I begin contemplating statistics when I board an airplane. Once upon a million years ago I worked for Boeing, all felt safe back then. Now, at least every other year I fly half-way around the world (and back)... it's a long flight to contemplate what if's....

By Lawrence (*****)

Date 01-22-2007 21:27

I have toured Boeings tube and tank facility in Everett.... There practices and methods are the toast of the industry. It was a real eye opener to see all those production catch phrases (first in first out, Synchronous Flow) actually put into action and work.

The process engineers at that facility are on the shop floor so that the craftspeople have access for realtime trouble shooting.... There excellence is unmatched.

And the oysters are good too.

By hogan

Date 01-22-2007 22:50

i used to x-ray a lot of airplanes and turbines up there. some had up to 400 shots per part, took a week to shot one.

By js55

Date 01-31-2007 18:03

Now this is touching upon some scary stuff.