Thanks to everybody for participation in solving my problem and helping me to search in the right direction. Just for your information problem is solved with decreasing of current in hot pass through decreasing of wire feed speed from 11 to 10.5 m/min. Process is now stabilised with no more...
We use the constant voltage power supplies and yesterday I decreased voltage on the power sources for 1 V and advised welders to increase the bug trevel speed (welding speed) in the area 3-5 o'clock and 9-7 o'clock (two welder operators CW - CCW) but did not solve the problem. We have 5 or more...
We can check visualy both ends of the pipe before fit up and didn't discover any low spots. In the meantime we decreased voltage on the source for 1.5 volts and now we still notice some spot fromtime to time but with less depth from botom side. Now it is acceptable concavity in the root. But it...
We are welding an offshore pipeline with Auto-GMAW process using copper shoes for backing during root pass.
We have a problem with root pass that ocurs like concavity spot 5 mm in dia. In front and after fault weld is completely sound. What could be the reason for such kind of fault? Is it some...
Please, could anybody explain to me in brief how to menage with toughness classes(CV1 to CV2ZX). Is it some characteristic to ask steel manufacturer to test toughness in special way and how it reflects WPQ CVN testing? What the supplier must do with CVN testing?If I am preparing WPQ for...
unclesyd
I am still checking this page but not from Sakhalin.I left Sakhalin project a month ago because of some other tasks in Europe. I was learned by my colleagues that nothing special has been happened on the project after earthquake. They even didn't feel it.
Concerning the problem we were...
I am afraid I did not understand you unclesyd. Why you said so?
Anyway, today we shall have the sample welded after all useful suggestions applied. In a few days will be the test reports and I shall let you know here about them.
Thanks stanweld.
I have the same question for you as I asked grampi1.
The content of Nb,V and Al in the pipe were:
Al=0.0031; V=0.075; Nb=0.045
Is it considerably higher in your experiance to contribute to diminish CVN particularly after PWHT?
We are now on the way to change ER 80S-Ni1 (Elgatig...
Thanks gramph1
Sorry for neglecting forum for a last week, but today I found some interesting contributions.
First, hardness values in WM and HAZ after PWHT were much lower than 250 HV with only two peaks in pipe side (with chemical content stated in one of my previous messages). May be it has...
Thanks 'metengr'.I agree.I think I am much closer to solve the problem.
Anyway I will try to use other rod for GTAW (with PWHT garanteed values)and take a care about welders skill and technique.
Please, contribute once more with your opinion, after receiving all asked clearances from the others...
Thanks 'stanweld', you were pointed a new fact for the problem.
It is true. We did had 4.65 - 6.22 cm/min speed for GTAW.
Regarding chem. content of X65 find it below and tell me your opinion...
Thanks 'GRoberts'.
I think I will follow your instruction to use ER80S-D2 or any other with properties after PWHT.
Your words 'Make sure plenty of filler wire is added to the root pass to help with this potential issue' mean that it is necessary to have such technique to diminish dilution with...
Thank you 'unclesyd' for your point of view and contribution, but let me ask you some details to make me clear your respond.
We have 3.5-4.2mm root gap which means less dilution in the root then with no gap. Do you prefer as much as possible less dilution and smaller amount of weld metal in the...
Thanks 'unclesyd' for your contribution to solve my problem.
I do not know about this application of TIG as a third pass. What should be the purpose of it? Usualy TIG is used for the root and after from the hot to the cup passes SMAW is used.
But you gave me an idea with "walking the cup...
Thanks for urgent response.
E8018-G is BOHLER electrode FOX EV 65 with:
C=0.06
Si=0.3
Mn=1.2
Ni=0.8
Mo=0.35
with 80J at -60 deg. C from BOHLER catalog
ER70S-6 is ESAB rod OK Tigrod 12.64 with:
C=0.1
Si=1.0
Mn=1.7
with 47J at -40 deg. C or
with 70J at -30 deg. C per ESAB catalog
If I am...
In this moment I am working as welding engineer on Sakhalin pipeline project. In the last few weeks we are faced with constant notch toughness failures in welding qualification program. In spite of all my experience there is lack of time and possibility to explore the problem in details and...
Thank you 'metengr' and 'stanweld'. You both helped me.
It was my humble thought (extended time), but I'll have to take care during proscribing of WPSs and qualification about this extended of time regarding EN 13445-4 (Page 46) and some limit of 3 hours and PWHT temperature to be less than 30...
I agree with you 'metengr'. It is also logical to me, in the light of welding technology, but I realised that ASME sentences and statements sometime are clumsy expresed. So I should wright gor 407.1 a(1) No/Yes PWHT or with/without PWHT and it would be much clearer and in correlation with our...
Thanks 'metengr'. Seems to be my angel on haven.
But, let me ask once again. I understood you and 407.1 demands concerning transition temperatures. But let me ask directly:
If I have qualified WPS without PWHT, can I apply stress relieving PWHT (below lower transformation) in production without...
metengr;
I have qualified WPS with PWHT. I want to apply this for the repair procedure of the same weld without re-qualification of all this in a row (weld+PWHT+repair+PWHT). Is it possible?
