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  • Users: CalvinKelly
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  1. CalvinKelly

    carbon steel to stainless steel weld

    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...
  2. CalvinKelly

    Material melting, or is it wearing away? see picture

    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...
  3. CalvinKelly

    Pitting During Salt Bath Heat Treating

    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...
  4. CalvinKelly

    Elevated Properties of Steel and Stainless Steel

    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...
  5. CalvinKelly

    What is the difference between AISI 430 and AISI 304-2B??

    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...
  6. CalvinKelly

    316 stainless and copper corrosion

    The copper will galvanically corrode. James Kelly James Kelly www.rolledalloys.com
  7. CalvinKelly

    Propeties of 304 stainless at 2000 deg F

    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...
  8. CalvinKelly

    Stainless Steel Selection High Temp Environment

    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...
  9. CalvinKelly

    Question about long term/short term stress in 316SS...

    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...
  10. CalvinKelly

    Searching for special ally steel

    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
  11. CalvinKelly

    Lubricity of cobalt

    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
  12. CalvinKelly

    Max. Allowable stress for Alloy 2205

    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...
  13. CalvinKelly

    Preconditioning of charge trays and fixtures.

    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...
  14. CalvinKelly

    CHROME EXTRACTED FROM STAINLESS STEEL

    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...
  15. CalvinKelly

    Looking for stainless steel that can be forged

    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...
  16. CalvinKelly

    Super Duplex 25 Chrome?

    A couple of other things to consider in alloy selection. The prime one is Availability--if you want a full mill heat you can get anything you want. But if your components total just a few thousand pounds of metal your choices are more restricted. Some alloys are only available as plate, others...
  17. CalvinKelly

    change in modulus of elasticity with high temperatures

    Modulus data for 304 may be found on Allegheny Ludlum's site, look up one of their Blue Sheets. The important point is that above ~1000F (540C) deformation becomes time dependent. Stress is no longer proportional to strain, i.e., Hooke's Law is repealed above this temperature. Nevertheless...
  18. CalvinKelly

    Stress Relieving 304/316 SS

    The usual steel stress relieving temperature, around 1100F (600C) does not relieve much stress in austenitic SS but can make things worse by causing intergranular carbide precipitation. One European oil company told me they were able to use 304H stainless in environments where polythionic acid...
  19. CalvinKelly

    Dr. Vogel's Sparbeize

    Does anyone know where an American might be able to purchase this aid to metallography? European stainless mills use it in their labs but the source is a secret to those of us on this side of the Atlantic James Kelly www.rolledalloys.com
  20. CalvinKelly

    Laser cutting titanium

    Thanks for the laser site, all I need to do now is figure out which book I need. We already do waterjet cutting, laser is fa$ter with much better tolerances (with all respect to Socrates, we do not question the breeding of our customers). & why would one have hydrogen embrittlement laser cutting...

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