Thanks for sharing the information. A thickness of 18mm may be possible to be cold formed, subject to the heat treatment, mechanical properties and the level of NDE done on the plates in the mill. Any cold forming with deformation(strain) exceeding the specified value as below should be followed by short stress relieve cycle , prior to any welding.
Or else it better to do warm forming of the plates. You may directly approach the manufacturer if procured directly any mill.
Irrespective of cold or warm forming, it's always advisable to have a good shop QA/Q.C , Welding & NDE practices in place while handling Grade 91 steel.
Thanks.
P.Goswami.P.Eng, IWE.
Welding & Metallurgical Specialist
Linkedin: https://www.linkedin.com/in/pradip-goswami-2999855/
Email:pgoswami@quickclic.net,pradip.goswami@gmail.com
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Brajendra Singh
Sent: March 24, 2018 3:03 AM
To: materials-welding@googlegroups.com
Subject: [MW:27554] RE: 27548] RE: 27542] Rolling/forming method for Gr.91 Plate
Dear Sir,
Thanks for your valued suggestions.
Thickness & dimensions of shell & dish end are as below.
For shell: requirement of diameter to be formed is 26" with thickness 18 mm.
For Dish End : required diameter is 26"
Regards,
Brajendra Patel
Sent from Mail for Windows 10
From: PGoswami
Sent: 23 March 2018 19:55
To: materials-welding@googlegroups.com
Subject: [MW:27548] RE: 27542] Rolling/forming method for Gr.91 Plate
Hi,
What's the thickness and the diameter involved? It's not always possible to guess the thickness from photographs due to enlargement. Cold forming generally should be avoided for grade-91 steel.
Grade-91 steel is a high tensile steel. Cold bending could lead to cracking and other metallurgical consequences.
API-TR- 938-B recommendations for cold bending of this steel are as follows:-
- The degree of cold working is usually limited to 17 % maximum (wall thickness reduction), if steels are applied at creep range temperatures.
- Most users would require that cold worked 9Cr-1Mo-V steels be normalized and tempered if the steels are applied in the creep range and the degree of cold working exceeds 17 %.
- Cold deformation requires heat treatment by most codes for deformation greater than 5 %
You need to think about warm forming to be on the safe side.
Appreciate response with details.
Thanks.
P.Goswami.P.Eng, IWE.
Welding & Metallurgical Specialist
Linkedin: https://www.linkedin.com/in/pradip-goswami-2999855/
Email:pgoswami@quickclic.net,pradip.goswami@gmail.com
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Brajendra Singh
Sent: March 23, 2018 3:19 AM
To: materials-welding@googlegroups.com
Subject: [MW:27542] Rolling/forming method for Gr.91 Plate
Dear expert's,
Please share the forming/rolling requirements for A387 Gr.91, we have tried cold forming/rolling of shell & dish end but always cracking.
Attaching photographs for refrence.
Thanks in advance
Regards,
Brajendra Patel
Mob:+917057406907
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