NORMALIZING OF DIHED HEAD AFTER HOT FORMING

[asad azmi]

Dear All,

 

Greetings.

 

A Vessel has to be fabricated as per ASME SEC VIII DIV 1.  Vessel requires SPWHT as per Client requirment.

 

 A Dished head of material SA 387 GR 12 CL2, Normalized and Tempered - 80  mm Thickness, has been HOT Formed at temperature 920 deg. Celsius. 

 

As per Hot Forming Procedure after reaching soaking temperature of 920 deg celsius and holding for 1 hour,  Hot forming operation was performed outside the furnace and immediately after hot forming dished head was put back in the furnace and  temperature was again increased upto 920 dec celsisus before transferring dished head in Shop Floor for  cooling.

 

As per ARAMCO Standard Noramilizing and tempering  shall be perforemd as seprate operation after Hot forming as per below clause.

 

13.2.14.1 Heat-treatment, as a separate operation, shall be performed after a forming operation (hot or cold) for any of the conditions listed below. The heat treatment shall be annealing, normalizing, normalizing and tempering, or quench and tempering, as required.

 

Please be informed that as per hot forming procedure Noramalizing after forming has to be performed at 920 Deg Celsius.

 

Contractor has not performed Normalizing sepratley after Hot forming.  as per reports test coupon has also undergone only ONE Normalizing Cycle.

 

Please advise whther Normalizing can be avoided as the hot forming was done at Normalizing temperature. 

 

As per ARAMCO requirement Heat treatment cycle  for Dished head & Test coupon should be  Hot forming  + Normalizing + tempering + SPWHT.

 

Please suggest.

 

Thanks in advance.

 

Regards

 

Asad Azmi

[Vanchinath S.A.]

dear,

normalising cannot be avoided even if dish is hot formed in normalising range.

vanchi

--
To post to this group, send email to material...@googlegroups.com
To unsubscribe from this group, send email to materials-weld...@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.

[R.Lenin]

Dear Azmi,

According to 32-SAMSS-004 paragraph 13.2.14,heat treatment such as
normalizing,annealing,normalizing and tempering or quench and
tempering shall be performed after forming operation for heads or
other double –curvature components with nominal thickness exceeding 50
mm and / or any hot formed components.

This requirement may cause a problem when tempering operation is done
at mill because subsequent teat treatment above tempering temperature
at mill will ruin the mechanical properties certified at mill. Many
mills produce heavy wall plates using tempering process to meet
mechanical properties required by project specifications.

Recently ARAMCO revised the same paragraph of 32-SAMSS-004 to allow
PWHT as the heat treatment for the parts.

The temperature of PWHT can be set below the tempering temperature ,so
it will not be a problem.

Thanks & regards,
R.Lenin
QA/QC Engineer,
GHI

On Feb 6, 9:58 am, asad azmi <azmiasada...@gmail.com> wrote:
> Dear All,
>
> Greetings.
>
> A Vessel has to be fabricated as per ASME SEC VIII DIV 1.  Vessel requires
> SPWHT as per Client requirment.
>
>  A Dished head of material SA 387 GR 12 CL2, Normalized and Tempered - 80

> mm Thickness, has been *HOT Formed at temperature 920 deg. Celsius*.

>
> As per Hot Forming Procedure after reaching soaking temperature of 920 deg
> celsius and holding for 1 hour,  Hot forming operation was performed
> outside the furnace and immediately after hot forming dished head was put
> back in the furnace and  temperature was again increased upto 920 dec
> celsisus before transferring dished head in Shop Floor for  cooling.
>

> *As per ARAMCO Standard Noramilizing and tempering  shall be perforemd as
> seprate operation after Hot forming as per below clause.*

>
> 13.2.14.1 Heat-treatment, as a separate operation, shall be performed after
> a forming operation (hot or cold) for any of the conditions listed below.
> The heat treatment shall be annealing, normalizing, normalizing and
> tempering, or quench and tempering, as required.
>
> Please be informed that as per hot forming procedure Noramalizing after
> forming has to be performed at 920 Deg Celsius.
>
> Contractor has not performed Normalizing sepratley after Hot forming.  as
> per reports test coupon has also undergone only ONE Normalizing Cycle.
>

> *Please advise whther Normalizing can be avoided as the hot forming was
> done at Normalizing temperature. *
> **
> *As per ARAMCO requirement Heat treatment cycle  for Dished head & Test
> coupon should be  Hot forming  + Normalizing + tempering + SPWHT.*
> **
> *Please suggest.*
> **
> *Thanks in advance.*
> **
> *Regards*
> **
> *Asad Azmi*

[vijayan]

Hi

 

// As per Hot Forming Procedure after reaching soaking temperature of 920 deg celsius and holding for 1 hour,  Hot forming operation was performed outside the furnace and immediately after hot forming dished head was put back in the furnace and  temperature was again increased upto 920 dec celsisus before transferring dished head in Shop Floor for  cooling.//

 

Generally the necessary heat treatments shall be applied after the specific fabrication process. Here the dish end heated to 920 deg C for ease of fabrication and as part of fabrication and could not be considered as heat treatment. The heat treatment if any shall be done separately followed by fabrication.

 

// Contractor has not performed Normalizing sepratley after Hot forming//

 

Normalising shall be done after forming as a separate process. After forming, the dish end shall be brought to at least 425 deg C and reheated to normalizing temperature. ref UCS-56d1.

 

// as per reports test coupon has also undergone only ONE Normalizing Cycle.//

 

The test coupon also shall undergo the same heat treatment cycle as required for the final vessel. (here the hot forming cannot be considered as heat treatment and can omit for test coupon.) Ref UCS-85(c)

 

// Please advise whther Normalizing can be avoided as the hot forming was done at Normalizing temperature. //

 

Hope the above clarifies the situation.

 

BR

M.Vijayan

--

To post to this group, send email to material...@googlegroups.com
To unsubscribe from this group, send email to materials-weld...@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.

---

This communication and any files transmitted with it are confidential and may also be privileged. It is for the exclusive use of the intended recipient(s). If you are not the intended recipient or the person responsible for delivering it to the intended recipient(s), please note that any form of distribution, copying or use of this communication or information contained in it is strictly prohibited and may be unlawful. If you have received this communication in error please return it to the sender, and delete the material from any computer. We reserve the right to monitor email communications through normal internal and external networks. We believe but not warrant that the email and the attachments are virus free. The statement and opinions expressed in this communication are those of the writer and do not necessarily represent those of Madina Group, whose registered office address is

P.O. Box 20459, Doha, Qatar.
Tel. +974 44600818
Fax. +974 44603143