Thanks for your detailed analysis.
we are using E316-17 and E316-16 in our power plant project.
After using these electrodes with quivers , we are not facing this issue now.
Thanks for your support
mahendra
From: "claes.gillenius@esab.se" <claes.gillenius@esab.se>
To: materials-welding@googlegroups.com
Sent: Mon, November 9, 2009 12:02:36 PM
Subject: [MW:3615] Re: E316 SS plate - porosity issues
The most commonly used stainless welding electrode (MMA) is the rutile acidic type, E3XX-17 (E3XX-16) according to AWS A5.4. This type of electrode contains only a relative small amount of limestone, which gives off the shielding gas (CO2) when welding. If the coating is not very dry, the content of water vapour in the shielding gas becomes high and there will be a porosity problem. Basic stainless electrodes , E3XX-15, according ro AWS A5.4, contain much more limestone, which gives more CO2 shielding gas. They can stand much higher coating moisture without giving porosity. Another problem with the -17 types is that they tend to pick up moisture rather quickly in warm and moist climate. Keep such electrodes in heated quivers, warm holding ovens etc. Rebake them at a rather high temperature, up to 350 °C. These electrode coatings are less sensible to heat than mild steel low hydrogen electrodes, so they can be rebaked at high temperatures many times if necessary.
Basic stainless electrodes (-15) can be rebaked too. They should be rebaked at a lower temperature, up to 300 °C, should be enough, and they are probably more sensitive to repeated rebaking than the -17 types.
Best regards,
Claes Gillenius
Development Engineer, MMA. (Spec. stainless and non Fe-alloys)
Direct tel: +46 (0)31 509315
Mobile +46 (0)707532012
Company ESAB AB
Address Box 8004, 402 77 Gothenburg, Sweden
Lindholmsallén 9
Company reg number 556005-7738
| mahen dran <cbemahendar@yahoo.com> Sent by: materials-welding@googlegroups.com 2009-11-07 14:57
|
|
Hi,
I am mahendra from KSA.
using 316L oerilicon electrode over 316L plate ((Flange joints - thickness around 8 mm)),
which creates porosity issue sometimes here . WPS and PQR are followed properly and there are no significant variation.
The electrode supplier suggests to use it in rebake oven.
We knows low hyd. electrodes which are ending with 5,6 and 8 are to be used with oven.
Is it correct way or normal proceudeure to use the SS electrode in oven ?
What is the control parameter to eliminate the porosity issue after welding (Especially in SS plate)
mahendra.t
This communication and any files transmitted with it contain information which is confidential and which may also be privileged. It is for the exclusive use of the intended recipient(s). If you are not the intended recipient(s), please note that any disclosure, copying, printing or use whatsoever of this communication or the information contained in it is strictly prohibited. If you have received this communication in error, please notify us by e-mail or by telephone as above and then delete the e-mail together with any copies of it. ESAB does not accept liability for the integrity of this message or for any changes, which may occur in transmission due to network, machine or software failure or manufacture or operator error. Although this communication and any files transmitted with it are believed to be free of any virus or any other defect which might affect any computer or IT system into which they are received and opened, it is the responsibility of the recipient to ensure that they are virus free and no responsibility will be accepted by ESAB for any loss or damage arising in any way from receipt or use thereof.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
-~----------~----~----~----~------~----~------~--~---
No comments:
Post a Comment