robertsolo

I would really love to answer that question , but I think you are figuring it out already , I feel like those germans no mater how few clues you drop , someone will figure it out . I am jeopardizing my job at this point , sorry but I must stop .

But with two material solution the temperature of the metal is lower , I thought we were talking about two material solutions now , in any case cold working the material is going to achieve necessary strength (at 1700 F ) I can tell you that with even testing it .

My numbers are from experence , even a thin liner can knock off the the top several hundred degrees , but as you go lower it gets harder and harder , like 2500-2000 is low hanging fruit , and 500- 200 is much harder to achieve . any theories ? ladle liners are usually oxides , remember fluorine will use oxides as Fuel . As to the different coefficients of expansion High conductivity is the way to fight that , carbon migration there are solid rocket nozzles (castor booster on the delta I think ) course that is very short duration but the shuttle boosters might accumulate some time maybe there was a study ?

Haynes International , reduction of the metal thickness when you cold roll most metal you will strengthen it that is how music wire ( drawn up to 440,000 PSI tensile ) and razor blades ( 500,000 -600,000 PSI Tensile ) are hardened . You were looking at the dead soft annealed numbers , look at the " Effect of Cold Reduction upon Room-Temperature Tensile Properties*" in the Haynes brochure and extrapolate from there , also razor blades have almost no elongation but are tougher than carbon fiber (low modulus ) with 4 % so there is more to it , or at least the rules don't seem to hold at very low elongations , any one got any theories ?

The company only gives properties up to 50% reduction that is very mild , on the Atlas program every time the ends did not meet they just specified a greater reduction , also just making a educated guess I would bet that the graphite lowers the temperature at least 700 F ( I can't make educated guesses in metric , I'm old school) and 900F does not sound unreasonable , also who knows what they are using . and even with 50% reduction you get 100,000 yield at 1700F and 33% elongation (at temperature) now raise the reduction you will increase yield and reduce elongation ( and you have some to spare there ) ... easy pesy , but I got to give credit where credit is due . It would be a smidge fragile when it was cold but still tougher than carbon carbon ( the 24 carrot gold solution , but getting cheaper ) Not wrapping it , lining it.

I am not proud of this but I read a paper ( a while ago ) written by a competitor (German) and they did not say ANYTHING specific , but they could not help but drop a few clues , and it just "clicked" , what the "Germans" are doing they are using a high temperature alloy probably similar to HAYNES® 214® alloy (UNS N07214) a nickel - chromium-aluminum-iron alloy, witch is off the shelf and way cheaper then some of the solutions I was thinking about and bonding a layer of graphite over it ( Graphite is good around fluorine and somewhat insulates the alloy armature and it is dirt cheap ! ) . They thought outside the box if you cannot find one material to do the job , try two ! I got to hand it to the Germans they got some good engineers , they made me feel like a amature , I am sure we will be copying them . Thanks guys

Yes yield is plastic deformation , before that you have elastic deformation , elongation happens after yield and before failure , In "critical" structures one tries ( but does not always succeed ) to have 10 % elongation in order to have a "tough" structure that bends ( hopefully away from the load , lessening it ) some , before failure . I am not trying to play "twenty questions" I work for a company in a competitive business . If you define "steel" as having 50% iron (not a accurate definition , you need to limit the carbon , or you will include cast irons ) then a lot of alloys I mentioned are steels but plenty are not and most of the high temperature alloys are not in high temperature alloys iron is used to reduce mix cost and provide sigma phase control . but what I am looking for is 200C beyond my experience with "common of the shelf " but 200C is just too close to not be possible today , especially with my willingness to make it a replaceable part with a limited lifetime.

8% that is nothing , lots of alloys/heat treats have elongations of 40% or more that is very common . Sorry I did forget to mention 85 hours of 10 minute " hot cycles" then cooling to room temp 20C

mind defining "steel" ? and that was not a requirement any way ,

Your kidding 125, 000 is not very high , there are hundreds of alloys/heat treats that exceed 125,000 PSI yield , I use alloys that exceed 220,000 Psi yield every day , and they been common since the 1950's , 2100F-2200F is very easy using off the shelf tubing , I am assuming a powder metallurgy alloy of some sort would be all that is required to raise the temperature 200F , not "off the shelf" but something that could be custom made if I find a facility with the right experience and no other jobs at the moment . I would guess yield at temperature of > 40,000 is within easy reach and 125,000 is a not unreasonable goal to shoot for.

I am sorry I thought I used all the common temperature scales but you seem to have a uncommon scale , very uncommon , why ? As to your Question I feel I have answered it.

Looking for a metal that can live in a Aluminium fluoride (AlF3) vapor > 1,290 °C (2,350 °F; 1,560 K) environment , have elongation > 5% better >8% . yield ideally >125,000 Psi. , lifetime > 85 hours . looking for something that will get the job done without "overkill".