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Up Topic Welding Industry / Technical Discussions / Base Metals
- - By RonG (****) Date 07-26-2000 15:37
I realize this is not an ASME Forum but a lot of you good folks know a great deal about Sect IX.
I have a question on QW-403.1, 4, & 5

If I have qualified P5A to P1 useing 309 in SMAW, GTAW & GMAW Am I correct in assumeing that each of the base metals are qualified to its self useing the same essential variables?

If so, this can save me from doing extra PQR's. And while I am at it! Can I use all three processes to weld one PQR. The way I read it, it should be Okay but it is confusing to say the least.
Parent - By R. Johnson (**) Date 07-26-2000 21:47
QW-403.1 and QW403.4 are not essential variables for any of the three processes you listed (SMAW, GTAW and GMAW). QW403.5 is a Supplementary Essential Variable for each of the three processes and will only apply if notch toughness tests are required. See the tables in QW-253, QW-255 and QW-256.
See QW-424 for base metals qualified by welding P5A to P1 materials. You get there because each of the table list QW403.11 as an essential variable and it takes you to QW-424.
You may qualify multiple welding processes on the same test plate, BUT you must pay attention to the weld metal thickness "t" (this is a little "t" and referrs to the weld metal thickness not the base metal thickness "T"). See QW404.30 which will take you to table QW451.1 for the limitations of weld metal thickness. This is why there is a weld metal thickness range on the WPS (QW-483).
Hope this helps.
Parent - - By Neal (*) Date 07-27-2000 01:05
Mr Johnson answer is right on the money, as usual. I am wondering about the reason for using this filler metal type for the base metal combination. Usually this combination is done with either the 70 series or 90 series depending on which side of the argument over strength match you want to take. Was PWHT involved?

Just kinda wondering why an austenitic was chosen?
Parent - - By RonG (****) Date 07-27-2000 18:10
Mr Johnson,
Thank you very much for your quick and informative response. I understood the "t" and "T" and was pretty sure of my ground on the other issues but I wanted to hear it from some one who knows. You make it look so easy. I spend a lot of time trying to familiarize my self and understand the code and mostly all I get is people looking down there nose at me. Your explanation was quite helpful it revield a new way to reference variables.
Neal and R. Johnson,
The application is not intended for joining but for overlay of seal and gasket faces also crush pads used to locate diffusers and diaphragms mostly in Boiler Feed pumps. The 309 gives good corrosion and errosion protection and reduces the need for PWHT. Not a high tech application I know but the powers that be have stated in there ISO manaul that we do all welding to ASME sect IX and they had know idea what they were getting in to and I was giving the dubious task of seeing that we do just that.
While I have you gentlemens ear. I am wondering if 309L might be a better choice. Dilution is not a problem for we premachine to keep the HAZ away from the finish. I know the 309L will work better in our new squirt gun but will I have to requailfy and would it be worth it?
I guess I am rambleing but if you dont mind, I would like to hear your thoughts on the subject.
Thank you for response.
Parent - By R. Johnson (**) Date 07-27-2000 20:38
No, you will not have to requalify when just changing from a E309 to an E309L. They are both the same F and A number.
I gather from your post that you are required to use the ASME Code but you do not have to have an AI inspect the part.
Parent - By - Date 07-27-2000 19:02
Just a short note to add to the correct information you have already been given. No, you may not use a P1 to P8 groove weld procedure qualification to write a P1 to P1 or P8 to P8 WPS. This is affirmed in Interpretations IX-95-22 and IX-89-78 (75).

I would like to provide a warning or perhaps a note. If you are claiming to qualify all welding in accordance with ASME Section IX, you had best not use the term corrosion resistance and overlay in the same sentence especially in the presence of your AI. If you do, your procedure qualification and WPS are governed by the QW-25X.1 welding variables and the requirements of QW-381 "Corrosion-Resistant Weld Metal Overlay". Most pelople try to avoid this if corrosion resistance is not of primary importance. But if corrosion resistrance is a significant concern or factor in your decision to perform the weld you must qualify this as an overlay not a groove weld. (see also QW-453, QW-462.5)

If you are trying to achieve corrosion resistance by all means use the "L" grade. The L grades (L means low carbon) of the austenitic filler metals are far less susceptible to intergranular stress corrosion or "knifeline attack" as the chromium remains in solution rather than forming chromium carbides along the grain boundaries. Carbide formation depletes the adjacent volume of chromium and it is the chromium that puts the stainless in stainless steel.

Parent - - By - Date 07-28-2000 00:37
In re-stating your first question, you've asked as per Sec.IX- If you qualified a PQR of a P5A base metal to a P1 metal with 309 filler metal using GTAW and by virtue of that specific test, can also claim (as an example) a qualification for a P1 to P1 and a P5A to P5A with the same filler metal and process?
Unless I've misread your question or somebody can show me where I'm missing something, the answer as per QW-424 is no.
If you had used a P5A-P5A test coupon, by that virtue you would have also qualified your P5A-P1 base metals combo as per QW-424 but not P1-P1.

As for your second question- "Can I use all three processes to weld one PQR"? The answer is yes and the previous posts give good quidance to thickness qualified.
Parent - - By RonG (****) Date 08-04-2000 02:49
It makes me dizzy at times but dosent QW-403.5 state that it does qualify? I know QW-424 Says P-5A to Any selection in the P-4,3 & 1. but back to QW-403.5 Dosent it elaborate on that?

I didnt mean that we used 309 for corrosion and erosion specificaly. Its paractice long established I suppose for in the field repairs to avoid the need for PWHT. I have a bad habit of useing those two words together, there should not (idealy) be any need for corrosion protection in this application. But they to get alot worm holes at times.

As for avoiding PWHT, sometimes when you are dealing with a finished machined part it is tuff to keep things from moveing around.

I am grateful for all the response for I know I am in over my head but at the moment I'm all we've got. And to make my point I have to ask,What is an AI?

I have a good idea but I need to know for sure.
Parent - By - Date 08-04-2000 11:58
Thank you for pointing out my oversight. The supplemental variable 403.5 does allow you to do as you've stated as the senerio described in my previous post.
Parent - By R. Johnson (**) Date 08-04-2000 13:38
An AI is an Authorized Inspector per definitions in ASME. Do you hold an ASME Code Stamp? Or are you just using the ASME Code as a reference?
Up Topic Welding Industry / Technical Discussions / Base Metals

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