Giovanni,
If I may be picky for a moment, just a point of interest. Some of the alloys in power piping are very sophisticated. Grade 91 used frequently for main steam and hot reheat came out of Oak Ridge and DOE research for nukes in the 60's. Grade 92, Grade 122, and many others of Japanese and German proprietary designation (spawned as well from this research) are rapidly finding application. Nickel, Vanadium, Niobium, Nitrogen, and other elements in extremely precise volume percents are finding there way into base alloys such as the traditional 1 1/4 and 2 1/4 Chromes, creating alloys of precise bainitic, martensitic and ferritic percentages.
And If I may, as an addenda not immediately applicable to your post, some of these alloys have evidence of some reheat cracking. Essentially any alloy with the potential for precipitation hardening, the potential for 'intra' granular precipitation of hardening carbides (often either V or Mo) or containing certain target elements (As, Sn, Cu, etc.), will. But typical PWHT regimes for many of these put them out of the range of robust formation of variables that initiate reheat cracking.
Your probably already aware of this but I thought it applicable. Its a good discussion. Reheat cracking a very real concern. But it has also become a catch phrase, and a marketing ploy. There is no escaping the need to engineer a safe and viable, and economical solution, and for a welding engineer to FULLY understand the alloy they are working with.
Sorry for the brief soapbox.
js,
thanks for the lesson. One learns something new every day.
You see, I live in a country where 90% of electric power comes from hydro plants.
With a couple of exceptions, the thermal plants belong to industrial mills (oil refineries, petrochemical, pulp and paper etc.) where the pressure very seldom exceeds 900 psi.
Out of the two existing nuclear plants, one was designed 30 years ago by a well known American company (which isn't General Electric) and was a fiasco. The other one was designed by Siemens and is working OK, but frankly I don't know the material the high pressure piping is made of.
And now let me ask you a question:
What do "picky" and "soapbox" mean? I'd have thought that soapbox is is a box full of soap that you buy in the supermarket.
Giovanni S. Crisi
"Picky" usually means being overcareful about the small details, and being hard to please. (I've sometimes used it to describe my mother. :) )
"Soapbox" is a reference to giving a lecture, sometimes but not always on a political subject. You're right that people could buy boxes of soap -- soapboxes -- at the supermarket; people used to use them to stand on to deliver lectures to a crowd when they needed a quick and easy way to stand up higher so the crowd could see them. So the term is now used as slang for lecturing someone.
Hope this helps!
-- Christine
Christine,
Well thank you. Let the record show that I neither intended to lecture our esteemed colleague, nor do I feel I was overcareful or hard to please.
And as a matter of tangent applicability, I recently printed up a power point presentation on a new Alstom Boiler Design, for those that are interested, or curious. And the alloys being utilized are staggering.
15Mo3, T91, 304H, Alloy 174, Alloy 617, Alloy 740, CrMo44, P92, Alloy C263.
Folks, this ain't your grandpa's boiler any more.
Back to the books.
No such implication was meant on my part :)
Christine,
I know. I suppose I didn't state myself well. We're cool.
js,
I'm going to ask you a favor and a question.
1st. Favor.
Two of my students at Mackenzie Presbyterian University in Sao Paulo are willing to prepare a monograph on 50% chrome and 50% nickel alloy, under my supervision.
The ASM Handbook shows a phase diagram of that alloy starting at 500° C. Here at Mackenzie's library there's nothing better than the ASM Handbook regarding metals and alloys.
Do you have a 50% Cr/50% Ni phase diagram starting at room temperature? If so, could you send it to me? My pupils and myself would thank you very much if you could do that.
2nd. Question.
Do you work for Alstom? I understand that Alstom boilers are the same that years ago were known by the brand of Combustion Engineering, because Combustion Engineering was bought by Alstom. Is that right?
Regards
Giovanni S. Crisi
Combustion sold to ABB, then ABB sold to Alstom. Alstom has made some changes, not many however.
Giovanni,
I'll be gald to look and see what I have.
As for Alstom, no I don't work for them. I was googling boiler design just trying to keep up with technology. I've been out of the power loop awhile. I thought I'd post the alloys. The sophistication and specificity of the alloys utilized surprised me, though I suppose they shouldn't have. I would certainly think that other boiler OEMs are designing to specifications just as sophisticated.
Giovanni,
I haven't forgotten you. The only thing I've found thus far are Pseudobinary phase diagrams with Cr and Ni in an Fe matrix. The iron being stable, while the Ni and Cr vary in reverse of each other. This is typical of stainless steel soldification studies. This is where I started looking.
I will keep looking but I really don't think I have such a beast.
I have a bunch of nickel base stuff in storage. I look there next.
js,
I'm sorry for the disturbance I'm causing you. If you think the search is troubling you so much, please give up.
Giovanni S. Crisi
Giovanni,
Its really no trouble at all. I have steadily been pulling some stuff out of storage. There are some other things I'm looking for and have ben unable to find. The EPRI report on weld discontinuities discussed in another thread, Gunn's book on duplex (not cheap-Ido not wish to buy this one again), and actually the most important is a book on Mechanical Metallurgy that I can't find. So I'm looking through this stuff ayway. Not to worry.
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