P91 - Main Steam Piping Failure - CHINA

I am just catching up on a rather spectacular failure of a P91 Main Steam system in October 2006 at a powerplant in China...

Although there seems to be a lot of speculation at this point, there are two excellent threads on www.eng-tips.com about the failures.

http://www.eng-tips.com/viewthread.cfm?qid=176859&page=1

http://www.eng-tips.com/viewthread.cfm?qid=172967

There is speculation, at this point about improper heat treatment ( a classic problem for P91 materials) and possible fraud in the substitution of seamed pipe for seamless.

I am only sorry that this incident occured in China, as a detailed investigation and scientific study of the incident probably will not occur due to the politics and secrecy of this nation. You could bet that there would be hell to pay if this occured in Europe or the US.

Does anybody have any other references or experiences to add or know anything more about this failure ?

Regards

_MJC

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I don't have anything to add, I just want ed thank you for posting the informative threads.

Our AI sent us the two pictures attached to the second thread a few weeks ago, but none of the details were included.

This kind of thing adds fuel to the petro-chem industry practice of conducting PMI on materials used for high energy systems.

It's a real shame this occured.

Charles

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Thank you for your comments Charles..

I have been researching and following the "saga" of P91 piping in the industry for a couple of years. I have seen all of the slick sales presentations by MBA laden "managment teams," consultants, snake oil salesmen and others who extol the virtues of a material with the remarkable high temperature properties of P91. "Thinner pipe.....less cost.....less structural support steel".....yeah yeah...

I have been most deeply concerned and interested in the problem of correct post weld heat treatment and "Type IV" cracking......a type of defect which only shows up after a couple of years of service.

Proper post weld heat treatment seems to be something only the Europeans can do correctly, not a lowest-bid US contractor......and certainly not the "slap-it-togther" Chinese..

By the way, there was an announcement yesterday of the first "ultrasupercritical power plant" to be built in the US. Will we use the new higher chrome material for this plant ?

In my opinion, people will be killed from poor seam welding and heat treatment, similar to what has happened to all of the low chrome-moly P11 piping installations in the 1980s-1990s. (anybody remember the deaths at the Mojave Plant and the disaster at Mt. Storm ? There are still P11 systems out there...)

I only hope and pray that when the next poorly welded P91 system lets go that a State Governor or US Senator or CNN is in close proximity. Then and only then will this threat be addressed.

This is my opinion only.....

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