From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Bathula Raghuram (Mumbai - PIPING)
Sent: Wednesday, September 23, 2009 11:53 PM
To: materials-welding@googlegroups.com
Cc: piping_valves@yahoogroups.com
Subject: [MW:3297] 3295] Welding qualification of very low sulfur steels.
Dear Kannan
Welcome on board after long time
Before seeing the link provided below, I thought you were asking for a CS material, and quite surprised by this claim that low sulfur will affect the weld quality?
Sulfur is an impurity in terms of steel making, and even weldability point of view, it was never an issue at least for process plant equipment or piping welding, the lower is the better.
It is quite common for offshore O&G application (where HIC/SOHIC/SSCC is envisaged) with such low sulfur content (Dillinger is one such manufactures for plates, their Dicrest series plates are guaranteed with S £ 0.0010 %).
Your specified sulfur conentnt restriction is for SS or CS ( or Duplex?)
The article mentioned in the below link related to small dia SS tubing welded with Autogenous Orbital GTAW, it’s a typical case. Never an issue for our type of applications
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of S. Kannan
Sent: Thursday, September 24, 2009 12:05 AM
To: materials-welding@googlegroups.com
Subject: [MW:3295] Welding qualification of very low sulfur steels.
----- Forwarded Message ----
From: kannan_cit <kannan_cit@yahoo.com>
To: piping_valves@yahoogroups.com
Sent: Wednesday, September 23, 2009 7:26:46 PM
Subject: [piping_valves] Welding qualification of very low sulfur steels.
Quit some time ago, I was having great difficulty in finding mills manufacturing steels with sulfur limited to 0.001% max. due to a wrong prescription by one of the well known PMC. Though it was resolved with higher relaxation later, I started to look into the issues concerning the restrictions posed in the sulfur content in steels, which were mainly added to increase the machinabilty, in various applications including the H2S/Sour service applications. The article in the link provides an insight in welding a low sulfur material.
The issue in the context of welding is that, while sulfur content is reduced the surface tension is reduced resulting in wider concave welds with lesser penetration, which pose a problem in thick walled pipes which are common in sour services. The insert ring solution proposed in the link below may solve the problem of higher weld penetration, which calls for different weld procedure. Similar to ASME BPE standard's prescription of limitation on, weld sulfur with appropriate quality check, does such requirement called in the BPV.
I seek our member's suggestion on the subject of welding procedure qualification, in such applications where sulfur content is restricted from 0.002% to 0.010% in sour/H2S applications.
http://www.thefabri cator.com/ tubepipefabricat ion/tubepipefabr ication_article. cfm?ID=533
With regards,
Kannan
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