inspection in between runs

Date 12-03-2009 17:12

matin08
Not enough information to really help.
Are the electrodes maintained properly, is the material prepped properly, are you using backing, do you have a good root spacing.
SMAW here with properly maintained E7018 usually gives excellent results. I am not familiar with 700Re .
I wouldn't dye Penetrant anything I didn't have to until welding id complete as it might lead to contamination itself, but these are my experiences and thoughts. Check this paper out http://www.ligo.caltech.edu/docs/T/T060113-00.pdf and clause 5.1 last sentence, Dye Penetrant may only be used on a practice weld configuration and never on a final assembly.
Good Luck
Marshall

By 3.2 Inspector (***)

Date 12-03-2009 17:12

Yes, this is regular :)
Except I would use MT.

3.2

By Lawrence (*****)

Date 12-03-2009 20:19

Matin

I think Marshall put a good start to the conversation.. First off we need more information (pictures and procedures if possible)

But it is a dangerous road to take when you adopt the notion of inspecting quality into a project..

It sounds more like a process control issue that might be solved by getting a better handle on the process itself.

Adding inspection steps may..*may* just be an unnecessary and expensive addition... But we need to know more.

By matin08 Date 12-04-2009 09:36

Right,
It’s a repair weld on a plate for a crack about 1meter long 10mm plate The rods are straight from a sealed packed and run better with a little warming to 70c

Single vee welded from one side in PC , I think that is 3G to you. .(Horizontal). First run 2.5mm 70amps the rest are 4mm rods 130amps The plate is at 100c due to attachments on the back of the repair with a CEV of 0.5

The good bit. This will be issued to contractors out of my control. You can not UT or xray the finished joint and therefore I was thinking a good idea include a method. Do run one. Grind back dye pen photo, next run, grind back photo. Ect. Long winded but this is likely to crack again under load should it have large inclusions in it from a poor weld that the contractor knows will not be radiographed. Or just misses. add photos of repair to servise record and send them to me.

This in one off repairs, not production.

We have done two weld pros and both cleaned but failed xray on Pours and inclusion.

By Lawrence (*****)

Date 12-04-2009 12:15

Matin

Repair is a horse of a different color!

The notion of Dye Check on a repair makes some sense.. (with strict controls in place as welds and oil based dye are not friends)

I did not like your plan at first, thinking it was intended for production.

also: For us 2G is a Horizontal Groove weld. 3G would be vertical.. :)

Let us know how you ultimately decide to proceed and how the project comes out.

By flamin

Date 12-05-2009 03:27

Would the dye, developer, or cleaner have any contaminating affects on welding, if it were used for interpass testing? Once that stuff seeps into a void, it's virtually impossible (or so it seems) to completely remove it with the cleaner. I can see the heat of the arc burning it out, but would it contaminate?

By HgTX

Date 12-07-2009 16:18

Wouldn't the idea of the PT to begin with be to have to grind out the void?

I've seen people use it to make sure they backgouged enough for the second side of the weld. We made them use water-soluble products and spray the weld off and dry it before they continued. (And then there was that one time they "forgot" to clean off the stuff and started their preheat and baked it on...that was pretty.)

Hg

By 3.2 Inspector (***)

Date 12-05-2009 07:40

Standard question: Can the welders weld, or did you just pick them up at the pub down the road?
In my experience the cause of inclusions and porosity is due to bad welders.

You mention "sealed pack" is it vacum pack or just the regular old style packs?
Why cant you x-ray or UT the finished weld, I guess if you can weld it, you can also atleast UT it.

3.2

By matin08 Date 12-07-2009 08:13

vac pac, and then said welder is experienced. I am told that some of the repairs will be in places where is will be difficults to get a welder to to the job nerver mind a qualifed NDt tec. Somalia is one of the places. India another, anybody fancy it. My job is just to set the welding parameters and recomend method.

By CWI555

Date 12-07-2009 14:09

I am still a little unclear of why you can't radiograph it, but I will approach it from the aspect of a golden weld.
I am not familiar with your material spec 700re, . I will assume there is a reason your cannot MT the material in question. (If you can it would be your better option)

In the states, a golden weld is considered one where it cannot otherwise be examined by volumetric method in the Oil and Gas world (RT, UT)
For those welds, each pass is individual examined as you've described. However; you've listed a temperature limitation that is usually not allowed for PT.
"The plate is at 100c due to attachments on the back of the repair with a CEV of 0.5"
That's 212F. Typically, penetrant is limited to 125-135f.

Therefore you will need a specially qualified PT procedure and materials.
To my knowledge, only Sherwin and Ardrox manufacture Hi temperature PT materials.
http://www.sherwininc.com/crossRef.html
Sherwin Penetrant K-017 and Ardox P303A
Those will have to be used with their matching cleaner and developer.
This procedure will have to be qualified at the maximum and minimum temperatures expected.
Suggest using Sherwin's KDS panels which are in compliance with ASTM E-1417.
At best this procedure will provide a sensitivity level 1.5 or so.

If memory serves me correct K-017 is only good up to 350F.

Hopes this helps,
Gerald

By 3.2 Inspector (***)

Date 12-07-2009 16:29

Dont worry about India, plenty of skilled welders there.

I dont really see what we are talking about here ;(
Do MT after each run and do a final UT?

If there is space to do MT/PT there should also be enough space to do UT.

If you can't get a skilled welder to repair it, how can you get a skilled welder to weld it in the first place?
Before having a welder perform a weld in confined spaces, just set up a test equal to the conditions at site.

3.2