Skip to main content

Re: [MW:22101] Re: MW: 8258- How to control cracks when weld P91 and P91

By Materials & Welding
Dear friends,
In my current job we maintain the interpass temperature between 200 to 300deg C for P91 material and let it cooling down after weld completed for RT ,so far no crack observed and the hardness test after PWHT showing good result

Best Regards

Mazlan Abd Aziz
Freelance Inspector
Email: mazlanaziz66@gmail.com
    
Mobile:+6019-4772079

On Mon, Oct 13, 2014 at 7:30 PM, pras ari <alhanif.pras@gmail.com> wrote:
Boxbe This message is eligible for Automatic Cleanup! (alhanif.pras@gmail.com) Add cleanup rule | More info

Dear Sir,

What can I do, if PWHT can't continue after weld joint complete because it will conduct RT on lower temperature ( < 50 degree), after RT pass PWHT will be proceed (may be 1 or 2 day after).
Please give me reference and heat treatment chart.


On Tuesday, November 16, 2010 11:20:16 AM UTC+7, pgoswami wrote:
Hello Liu,
 
I've attached some information on recommended welding consumables and welding parameters for P-91 steel. Being the products of Metrode certainly these products are very well known in the welding world.
 
The typical formula for heat input as per Sec-IX is = 
  =380X35X60 / 25=3192 J/mm =3.2 KJ/mm
 
The heat input looks to be  at least 25-50% higher than the optimum level 2-2-5. KJ/mm. This may be controlled by increasing the travel speed. SAW welds produces wider HAZ, as compared to SMAW or GTAW. Impact properties for SAW welds are relatively less than GTAW -P-91 weld metal One of the possible causes for reduced impact strength could be higher "Si" in the weld metal and relatively higher input in SAW
 
As regarding PWHT-- all welds in utility (power plant) services would require PWHT at 760°C ± 14°C (1400°F ± 25°F) minimum, regardless of wall thickness or diameter.
 
Te preheat and interpass temperature looks fine.The recommendations  would be :-
 
Controlling Cracks:-For controlling cold cracks, maintain the preheat, interpass control,immediate cooling to 100deg C for complete martensitic transformation as below. Hot cracks could be controlled through a strict control of:C" and 'Si" in the weld.
 
As regarding PWHT:- Ensure the PWHT temperature does not exceed the base metal tempering temperature and stays in the above mentioned temperature range. In fact it would be advisable to work out the best welding parameters after verifying the base metal CMTR(especially impact)
 
Thanks.
 
 
Pradip Goswami,P.Eng.
Welding & Metallurgical Specialist & Consultant
Email-pgoswami@sympatico.ca,
 

From: material...@googlegroups.com [mailto:material...@googlegroups.com] On Behalf Of Roy LIU??
Sent: Sunday, November 14, 2010 7:30 AM
To: material...@googlegroups.com
Subject: [MW:8258] How to control cracks when weld P91 and P91

Dear All,
I just meet a problem from one of my customers.
It is a Boiler Manufactory in China.
 
Details as follow:
base material: P91
process: SMAW (root) + SAW (filler metals)
Heat Input: high  
I=380A
U=35V
V=250mm/min
Preheat, Interpass Temperature: ≤250℃
 
How to control cracks?
How to increase impact properties afer PWHT?


 

Best regards

 

Roy LIU

--
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.

--
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/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
 
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.
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.


--
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/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
 
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.
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Comments

Post a Comment

Popular posts from this blog

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

Re: [MW:10788] ON PLOT PIPING & OFF PLOT PIPING

By Materials & Welding
Piping systems involved for the flow lines and gathering lines from the well head isolation valve to the production facility or processing plant isolation valve are determined as OFF PLOT. ON PLOT defines piping system in the processing plant and production platform. ANSI/ASME B31.4 applies for off plot piping system. B31.4 allows the use of either API 1104 or ASME section IX (as appropriate). However, occasionally, a very small system such as piping within 500 feet of a processing plant (some client also said 400 feet) may be declared B31.3 rather than B31.4. When B31.3 is invoked, only ASME Section IX is used. before you decide which code to use for welding procedure and/or welder qualification for pipe welding, you have to know the design and construction code applicable to the system. Please read far enough into scope and diagram illustrating the application of either B31.3 and B31.4 hope this helps rgds 2011/4/21 pradip kumar sil < pradipsil@gmail.com > Dear all, ...
Post a Comment
Read more