Re: [MW:20670] RE: 20642] Re: Stress Relieving of Titanium Grade 2 Tubes

On 4/22/14, pgoswami <pgoswami@quickclic.net> wrote:
> Hi Ashis,
>
> Please see the data sheet for general guidance. Titanium is usually
> considered immune to SCC. However cold formed bends may require stress
> relieving to keep the hardness under control, especially in the sour
> environments.
>
> What's your clients' specific requirements (hardness control) under the
> given design considerations.
>
> For example MR-15156-Part -3, Table, A-41, requirements are as follows:-
>
> *
>
> Specific guidelines shall be followed for successful applications of
> each titanium alloy specified in this part of ANSI/NACE MR0175/ISO 15156.
> For example, hydrogen embrittlement of titanium alloys can occur if these
> alloys are galvanically coupled to certain active metals (e.g., carbon
> steel) in H2S-containing aqueous media at temperatures greater than 80 °C
> (176 °F). Some titanium alloys can be susceptible to crevice corrosion
> and/or SSC in chloride environments. Hardness has not been shown to
> correlate with susceptibility to SSC/SCC. However, hardness has been
> included for alloys with high strength to indicate the maximum testing
> levels at which failure has not occurred.
>
> Thanks.
>
> Pradip Goswami, P.Eng,IWE
> Welding & Metallurgical Specialist
> Ontario, Canada
> pgoswami@quickclic.net
> pradip.goswami@gmail.com
> pradip_goswami@yahoo.ca
>
>
> _____
>
> From: materials-welding@googlegroups.com
> [mailto:materials-welding@googlegroups.com] On Behalf Of Raghuram Bathula
> Sent: Monday, April 21, 2014 6:19 PM
> To: materials-welding@googlegroups.com
> Subject: [MW:20642] Re: Stress Relieving of Titanium Grade 2 Tubes
>
>
> A stress relief treatment is sometimes employed following severe forming or
> welding to avoid cracking or distortion due to high residual stresses, or
> to
> improve fatigue resistance. Cleanliness of titanium parts to be heat
> treated
> is important because of the sensitivity of titanium to contamination at
> elevated temperatures. Titanium fabrications should be cleaned carefully
> prior to heating, using nonchlorinated solvents or a detergent wash,
> followed by a thorough water rinse. Handling following cleaning should be
> minimized to avoid potential surface contamination.
>
> Most titanium grades are typically stress-relieved at about 1000°F (538°C)
> for 45 minutes and annealed at 1300°F (704°C) for two hours. A slightly
> higher stress relief temperature [1100°F (593°C), 2 hrs.] and annealing
> temperature [1450°F (788°C), 4 hrs.] are appropriate for the Grade 5 alloy.
> Air cooling is generally acceptable.
>
> Although no special furnace equipment or protective atmosphere is required
> for titanium, a slightly oxidizing atmosphere is recommended to prevent
> pickup of hydrogen. Direct flame impingement for extended periods, leading
> to temperatures in excess of 1200°F (649°C), should be avoided because of
> the potential for contamination and embrittlement. Hydrogen or cracked
> ammonia atmospheres, also, should never be used, because their use would
> lead to excessive hydrogen pick-up, and embrittlement.
>
> more info can be found at
>
> http://www.keytometals.com/Article97.htm
> <http://www.linkedin.com/redir/redirect?url=http%3A%2F%2Fwww%2Ekeytometals%2
> Ecom%2FArticle97%2Ehtm&urlhash=WUkd>
>
> http://www.azom.com/article.aspx?ArticleID=1245
> <http://www.linkedin.com/redir/redirect?url=http%3A%2F%2Fwww%2Eazom%2Ecom%2F
> article%2Easpx%3FArticleID%3D1245&urlhash=oqin>
>
> On Tuesday, April 22, 2014 3:48:01 AM UTC+5:30, Materials & Welding wrote:
>
> Our client requirement states that Stress Relieving of Titanium U bends is
> mandatory. Our Metallurgy of Tubes is SB 368 Gr. 2 (UNS R50400)
> Tube side fluid is sea water and Shell side fluid is sour gas (172 bar
> Pressure and 170 deg cel at shell side)
>
> In view of above , please let me know , Is it really require to perform SR
> of Titanium U bends.
>
> NACE states that Titanium is susceptible to Stress corrosion cracking.
> Vendors are not in opinion of doing SR.
>
> Please provide your valuable input
>
> Thanks
> Ashish
>
>
> --
> 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/
> http://www.linkedin.com/groups/MaterialsWelding-122787?home=
> <http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk
> =anet_ug_hm> &gid=122787&trk=anet_ug_hm
>
> 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.
> ---
> You received this message because you are subscribed to the Google Groups
> "Materials & Welding" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to materials-welding+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>
> --
> 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/
> http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
>
> 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.
> ---
> You received this message because you are subscribed to the Google Groups
> "Materials & Welding" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to materials-welding+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>


--
Thanks & Regards
Pinaki Boxi.
Deputy Manager(QA/QC)
IOT-Paradip Site
Mob-+919178466059

--
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/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm

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.
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.