I believe power plant stainless to carbon steel welds fail from differential thermal expansion at temperatures somewhere around 600F or higher, plus diffusion of carbon from the steel into the weld. State-of-the-art, or so I understand, is to use ENiCrFe-3, a.k.a. Inconel 182, covered electodes...
What alloy are you using now?
It looks melted to me. Usually if it looks melted, it is melted. And if it is melted you'll have a hard time finding something else that doesn't also melt.
In my experience, coal nozzles supposedly running 1700-1800F have been known to melt (Texas, during a 1980's...
While you may have started with pure NaCl, it picks up oxygen from the air, and entrained oxygen when you submerge the part.
No heat treat salt bath will prevent oxidation of aluminum.
Out of curiosity, how did you contain the salt, and how did you heat it?
In my opinion, you ought stay with...
Temperatures around 1000F can severely embrittle ferritic or martensitic stainless grades with 12% or more chromium. Specifically, 430 and 410 will both suffer "885F embrittlement", while type 409 ~11%Cr is supposedly immune to this embrittlement.
Be really cool to know for exactly what grades...
I agree with Ed.
Try using "Lemon Jxx", or some other soap with implied orange/lemon/whatevercitric acid. The dishwasher soap used by my wife sometime in the last decade made some deep, deep pits under white deposits on my 18-10 flatware when the washed dishes were left unattended (in an older...
We have seen 304 approximately 1/4" thick disappear completely from oxidation in a few months at 1700-1800F. One reason you cannot find mechanical data for 304 above 1500F is that the oxidation resistance is too poor to make a good test specimen. Agree there are no reasonably priced bar alloys...
In Rolled Alloys' experience, most weld failures at high temperature are the result of incomplete weld penetration. One simply cannot get the same penetration in a stainless weld as in a carbon steel weld. Any plate 3/16" or greater needs to be beveled to get the weld bead deep into the joint...
For 1100F (593C) and above, 316H design stresses for pressure vessel use are based on the long-time creep-rupture properties. Tensile strength cannot be used here.
The reason is at this temperature and above the metal will deform slowly with time, and at stresses much lower than the short time...
304 Stainless (18Cr 8Ni austenitic) has expansion 15.8/C x10-6 near room temp I am aware of no steel with expansion remarkably higher than this
James Kelly
www.rolledalloys.com
At elevated temperatures high cobalt alloys form a scale which is somewhat lubricious. That is, at red heat cobalt alloys are less likely to gall than are nickel base alloys.
James Kelly
www.rolledalloys.com
While it is S31803 that is in the code book, most 2205 now is dual certified S31803/S32205. This latter UNS number has chemistry modified for better weldability & corrosion. If it meets S32205, it also meets S31803. Eventually the code will get around to recognizing S32205.
James Kelly...
Our experience is as a supplier of wrought alloys for trays and fixtures, since ~1945 ('53 officially). We are aware of no effective preconditioning treatment. Life of cast heat resistant alloy components depends very much on the quality of the casting, that is, the foundry source. Broken trays...
This is just a guess as I have no experience with plastic corroding stainless. But, 304 does not well resist corrosion from chlorides. Molybdenum is the alloying addition to stainless that improves resistance to chloride corrosive attack.
The most commonly available grade that is a notch above...
Forge-welding stainless will require a good flux to flux the chromium oxide scale that forms. In this respect I suggest you contact other damascus makers, rather than typical engineers who are profoundly in ignorance of damascus.
I presume you want the stainless part to be hard. I also suspect...
