Skip to main content

[MW:8713] RE: 8654] MW:8637- tempering of plates

By Materials & Welding

Dear sir,

 

In that case coupon plate (from the same heat) shall be placed during the hot forming operation and shall be tested (mechanical test required as per material spec) to ensure the properties retained after hot forming operation. My understanding is correct please confirm.

 

Regards

M.M

 

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of pgoswami
Sent: Friday, December 10, 2010 4:54 AM
To: materials-welding@googlegroups.com
Subject: [MW:8654] MW:8637- tempering of plates

 

Asad,

 

The plates are supplied with normalizing and tempering heat treatments, which is done in the mills with a great control. Since the head will be hot formed , forming temperature is typically > AC1 temperature (typically over 920 deg C for LAS), the effect of Mill-tempering would be lost.

 

Hence following hot forming the dished head has to be re-tempered (preferably at the tempering temperature used in the Mill).

 

How much is the variance in tempering temperature performed in the mill,i.e required as per code vs done at the mill(as indicated below). If the variance is minor, re-heat treatment of the plates would not be desirable. However tempering following forming (as mentioned above) would be needed.

 

To be on the  safe side and be assured of the plate quality, you may please ask for simulation test coupons (with multiple heat treatments as above) from the mill.

 

Thanks.

Pradip Goswami,P.Eng,IWE.

Welding & Metallurgical Specialist & Consultant

Email-pgoswami@sympatico.ca,

pgoswami@quickclic.net

 

 

From: asad azmi <azmiasadayub@gmail.com>
To: materials-welding@googlegroups.com
Sent: Wed, 8 December, 2010 6:47:01 PM
Subject: [MW:8604] tempering of plates

 

Dear All,

 

Greetings.

 

A vessel is to be fabricated as per ASME SEC VIII DIV 1 for data as below- use  

 

Plate Material  -  SA 387 GR 12 CL2  ,   80 THK.

 

Plate is to be used for dished head. as per the  ASME SEC IIA  normalizing and tempering is required for the plate.

 

forming of Dished head will be  by hot forming.

 

during reveiw of MTC it was observed that Tempering temeprature was not meeting the requirement.therefore re - tempering is required for the plate.

 

My question is whether re - tempering is required for the plate OR it can be done after Hot Forming of dished head.

 

As per the requirment after hot forming, dished head will under go Normalizing and tempering.

 

Pls suggest.

 

Thanks in advance for your valuable suggestions.

 

Regards

 

Asad Azmi

 

 

 

 

 

 

 

--
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/
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.

 

--
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/
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.

 

--
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/
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.

 

--
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/
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.

Comments

Post a Comment

Popular posts from this blog

Re: [MW:34105] SA266 GR4N 4 Cycle SPWHT

By Materials & Welding
Hi,  You are correct, Minimum refers to the one cycle for which this part will expose until final work shop PWHT. hence mill test certificate shall include this.  Max. SPWHT, refers to additional cycles of heat treatment that are reserved for future repairs during equipment lifetime.  Again, these simulated no. Of cycles shall be specified in MTC.  The idea is we need to make sure that steel mechanical properties are not compromised upon exposure to multiple repairs (i e 4 cycles in your case).  One could say, if steel is subjected to 4 cycles and is ok, then it should by defacto be good for one cycle, yet, this is wrong assumption cause mechanical problems and microstructure of materials varies accordingly based on no. Of cycles for which material will expose. This is apparent in alloy steel and especially for impact test values as an example.  In your case, this forged CS with properties before PWHT can be understood to be " as forged" condition (i.e. Wit...
Post a Comment
Read more

Materails FAQs

By Materials & Welding
Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...
21 comments
Read more

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

By Materials & Welding
Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...
Post a Comment
Read more