Hi,
On capping pass towards forging 3.2mm electrode both for 6'O CLOCK POSITION & 12 O'CLOCK POSITION in 5F position.
Regards
Sachin.Sankhe
On Sat, 12 Jul 2008 ramu oruganty wrote :
>Hello,
>Can I know which dia electrode was used at 6 O'CLOCK & 12 O'CLOCK position.
>Â
>Regards
>Ramu
>
>--- On Wed, 9/7/08, sachin sankhe <sachin.sankhe@rediffmail.com> wrote:
>
> From: sachin sankhe <sachin.sankhe@rediffmail.com>
>Subject: [MW:907] Re: Hardness variation on a temper bead welded F65 forging
>To: materials-welding@googlegroups.com
>Date: Wednesday, 9 July, 2008, 4:20 PM
>
>
>
>Â
>Hi,
>Actually as stated by me early we have first carried qualification in 5F position & later on 2F position.
>I had mentioned 6 O'CLOCK & 12 O'CLOCK position for 5F position
>
>Thanks for explaining the reason.
>
>Regards
>Sachin.Sankhe
>
>On Tue, 08 Jul 2008 Bathula Raghuram(Mumbai - PIPING) wrote :
> >It is some thing tricky, and difficult to evaluate the exact cause. Your
> >assumptions regarding HI could be the reason for this at a particular
> >position.
> >
> >But one thing is not clear to me, you welded this piece in rotating, how
> >do you identify the 12'o clock position, where hardness is more?
> >
> >Yes your conclusions stated below will help us definitely in due course.
> >
> >
> >
> >Regarding your query on the previous statement the right vertical line
> >is toe of the weld and left vertical line is toe of the surface temper
> >reinforcing bead, this is mentioned to give a rough idea of surface
> >temper bead placement, please note these surface temper beads may remain
> >in place or may removed by grinding.
> >
> >
> >
> >Â The in tempered HAZ as shown with arrow. Attachment in the previous
> >post shows the same for tempering this arrow marked portion.
> >
> >
> >
> >________________________________
> >
> > From: sachin sankhe [mailto:sachin.sankhe@rediffmail.com]
> >Sent: Monday, July 07, 2008 6:59 PM
> >To: materials-welding@googlegroups.com
> >Cc: Bathula Raghuram (Mumbai - PIPING)
> >Subject: Re: [MW:904] Hardness variation on a temper bead welded F65
> >forging
> >
> >
> >
> >
> >Dear Mr.Raghuram/Members,
> >
> >Let me apologise for not putting subject.
> >
> >Yes I had taken care as mentioned in your mail
> >As u can see in attached figure that 8th pass was done on 6th pass.
> >Distance between welding edge of 6th pass & 8th pass(i.e vertical
> >distance in your mail sketch) was 3mm
> >Yes preheating was done min. 150 deg.C & INTERPASS temp maintained at
> >180-190 Deg.C
> >
> >Also why it give high hardness on 12 O'CLOCK POSITION ONLY whereas it
> >was accaptale in 6 O'CLOCK position
> >
> >Today I could see Macro of all specimen from DNV,Lab(Singapore).I
> >compared weld profile of both 6'O CLOCK & 12 O'CLOCK specimen.I have
> >noticed that fusion line in 12 O'CLOCK was not straight i.e When fusion
> >line deviated far into base metal at that point hardness value was too
> >high.So I think welder shall try to maintain fusion line straight.
> >Note that 2F position hardenss was OK
> >
> >So Conclusion is
> >If hardness is critical to achieve
> >
> >1.Weld in such aposition that more Heat I/P can be done.In this case
> >preferable position was 2F compare to 5F
> >2.During capping avoid welding on base metal
> >3.Grind 1/4th or may be 1/2 of last fill passes before doing capping so
> >that we can get good tempering of last fill pass
> >4.Last Capping pass(Temper bead technique) shall be not that close to
> >base metal so that it makes its own untempered HAZ in base metal
> >
> >Views on above concluded points are welcome
> >
> >I was not clear on your below statement can u be bit more clear on this
> >
> >"The distance between two vertical lines (as shown in attached sketch)
> >shall be small enough that HAZ of reinforcing bead tempers all of the
> >unaffected HAZ in the base metal, but not so small that it creates its
> >own untempered region."
> >
> >Regards
> >Sachin.Sankhe
> >
> >
> >
> >
> >On Mon, 07 Jul 2008 Bathula Raghuram(Mumbai - PIPING) wrote :
> > >Dear members
> > >
> > >Request to use appropriate subject line, thou the topic was very
> > >interesting to discuss, it may be ignored by many in absence of an
> > >appropriate subject line.
> > >
> > >
> > >
> > >There are chances that toe of the weld, where no tempering of HAZ has
> > >occurred, in addition there is weld metal that is also not tempered, it
> > >may be necessary to add a layer on top of the completed weld and grind
> > >it off to get the desired results. This results in tempering of the
> > >remaining untempered weld and HAZ. But be careful not to let this extra
> > >tempering layer penetrates to base metal, if it, then you may create a
> > >new untempered HAZ.
> > >
> > >The distance between two vertical lines (as shown in attached sketch)
> > >shall be small enough that HAZ of reinforcing bead tempers all of the
> > >unaffected HAZ in the base metal, but not so small that it creates its
> > >own untempered region.
> > >
> > >(Remember) Cooling rate during welding : Thicker one cool faster than
> > >thinner ones, with lower heat input cool rapidly than higher heat
> >input,
> > >cooler base material cool quicker than hotter ones (did you preheat
> >this
> > >one?)
> > >
> > >
> > >
> > >
> > >
> > >Invite more discussions, and active participation, irrespective of your
> > >views whether right or wrong as only in discussion we can improve
> > >
> > >________________________________
> > >
> > > From: materials-welding@googlegroups.com
> > >[mailto:materials-welding@googlegroups.com] On Behalf Of sachin sankhe
> > >Sent: Saturday, July 05, 2008 6:52 PM
> > >To: materials-welding@googlegroups.com
> > >Subject:
> > >
> > >Dear Friends,
> > >
> > >Recently we have come across welding situation as mentioned below
> > >
> > >Details are as follows-
> > >
> > >1.Material used -API 5L X65 TO A694 F65
> > >2.Position-5F
> > >3.Welding Process-GTAW(Root,Hot)/SMAW(Fill, Cap)
> > >4.Welding consumable-GTAW(ESAB OK 13.09),SMAW(E8016 GH4R)
> > >5.Welding Technique-Temper Bead Technique
> > >6Reference Codes-API1104/NACE MR0175/DNV 0S F101
> > >7.Hardness Requiremnt as per Client Spec-248 HV10
> > >8.Size(12" O.D X 27.3 mm Thk to 2" O.D X 8.7 mm Thk)
> > >
> > >Situation-
> > >1.We carried out welding procedure qualification and sent for testing
> > >2.Testing to be carried out-NICK BREAK & HARDNESS
> > >3.Hardness on capping pass (12 O'CLOCK )at forging side found above
> >250
> > >HV10
> > >4.However at 6 O'CLOCK it was below 248HV10 & hence acceptable
> > >5.Due to failure at 12 O'CLOCK POSITION,we decided to re-qualify.
> > >6.This time we maintained high heat input(1.6-2.0 kJ/MM) on caping pass
> > >at forging side
> > >7.Hardness result again we found high at same location as
> > >previous,however on 6 O'CLOCK position it was less then 248 HV10
> > >8.Due to failure we decided along with client following option
> > >Â a)Two procedure to be qualified one in 5F position like prevoiusly
> >but
> > >this time we decided to rotate the pipe when welding capping pass on
> > >forging side i.e Welding to be carried out only b/w 9-6-3 o'CLOCK
> > >POSITION only.Thus avoiding welding in 12 O'CLOCK POSITION
> > >Also we decided to use even higher heat i/p by using larger dia.
> > >electrode (3.2 mm)in place of previoiuly used 2.5 mm electrode
> > >Â b)Secound procedure we decided to do in 2F position and maintaining
> > >higher heat i/p(1.8-2.5 kj/mm)on capping pass(Forging side)
> > >
> > >9.After hardness testing for 5F position results on 12 O'CLOCK position
> > >forging side again failed
> > >10.However in 2F position it was satisfactory with same heat i/p as
> >that
> > >in 5F position
> > >
> > >Would like to know the reason of such behaviour
> > >
> > >Sachin.Sankhe
> > >Engineer-Inspection
> > >Aker Kvaerner-Malaysia
> > >Mobile:012-2896901
> > >Email1:Sachin.Sankhe@akerkvaerner.com
> > >Email2:Sachin.sankhe@rediffmail.com
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >>
>Sachin.Sankhe
>Engineer-Inspection
>Aker Kvaerner-Malaysia
>Mobile:012-2896901
>Email1:Sachin.Sankhe@akerkvaerner.com
>Email2:Sachin.sankhe@rediffmail.com
>
>
>
>
>
>
>
>
>
>
>
> Unlimited freedom, unlimited storage. Get it now, on http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/
>>
Engineer-Inspection
Aker Kvaerner-Malaysia
Mobile:012-2896901
Email1:Sachin.Sankhe@akerkvaerner.com
Email2:Sachin.sankhe@rediffmail.com
 |
Comments