Skip to main content

[MW:1298] Re: max. Heat Input on WPS?

hi
for c.s ,if the fabrication process is TMCP,the h.i must be less than 25kj/mm.


From: PREM SHANKARDUTT NAUTIYAL <prem_nautiyal@rediffmail.com>
To: materials-welding@googlegroups.com
Sent: Tuesday, November 11, 2008 5:55:17 PM
Subject: [MW:1294] max. Heat Input on WPS?

  Dear friends

How do we specify heat input requirements for a particular process / material as per ASME Sec IX.
Now i have seen many clients specifying max. heat input as 2KJ/mm for Carbon steel welding. Some clients like BHAVINI / NPCIL specify max. heat input as 1200 J/mm for stainless TIG welding.
DO we have to put this heat input requirement on the WPS as per ASME Sec.IX if the construction code calls for impact testing ?? If there is impact testing involved then heat input becomes an supplementary essential variable, then how do we specify the max.heat input on the preliminary WPS before conducting the PQR ??
Are there any guidelines / thumbrule / literature available ?
How to calculate the optimum heat input requirement for various materials like Carbon steel , LAS, Stainless steel ( i am not talking about basic formula HI=V*I*60/Travel speed)

Please share ur valuable advice / experience .

Regards

Prem Nautiyal
Godrej, Mumbai

PREM S NAUTIYAL
CELL : 9820313278



--~--~---------~--~----~------------~-------~--~----~
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

Popular posts from this blog

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

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...

Materails FAQs

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...

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

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...
Rediff Shopping