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Re: [MW:27577] RE: 27542] Rolling/forming method for Gr.91 Plate

By Materials & Welding
Pls have a look in PG-20 in ASME BPVC Section I

2018-03-23 16:25 GMT+02:00 PGoswami <pgoswami@quickclic.net>:

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

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Dr. Georgios Dilintas,
Dipl. Ing. In Aeronautic and Space Engineering
Ph.D in Mechanics of Solids - Computational Mechanics
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Welding, Stress Analysis, Corrosion, QA/QC, Failure Analysis, Risk Analysis

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