Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. pwtomlin

    Steel Casting Test Coupons, Differences

    I agree with arunmrao. An integrally cast test coupon needs to be physically continuous with the casting. A gated test coupon would be separated from the casting by the gating system. Both methods would ensure that the casting and the coupon were poured using the same metal, which you don't...
  2. pwtomlin

    Zinc presence in C95400 Aluminum Bronze Alloy?

    Cast C95400 typically contains small amounts of Zn, typically around 0.15 wt % or less. This commonly comes from the ingot manufacturers and contamination from other bronzes and brasses made in the same furnaces. I do not know of any problems with corrosion of this alloy resulting from Zn...
  3. pwtomlin

    c276 overlay of cast 625

    I have a customer who is having using overlaying part of a Alloy 625 casting with ERNiCrMo-4 (C-276) weld wire. I don't have a lot of details but they are seeing "tearing" (cracking?) at the weld-base metal joint. I realize that's a pretty vague description but has anyone encountered a similar...
  4. pwtomlin

    Casting cross over for Inconel 693

    I see this alloy has 2.5-4.0% aluminum. I really doubt you would find an ASTM specification for a cast version. You're likely looking at vacuum melting, and if the part you want can't be investment cast I'm not sure how much success you will have finding someone who can cast it at all. Not...
  5. pwtomlin

    Suitability of 2304 lean duplex vs 316

    I'm not sure how much cost savings you are going to see trying to transition from cast 316 (CF8M) to cast 2205 (CD3MN) or CD4MCuN. Obviously, there is less alloying content but the duplexes are harder to cast well so there is less competition. I would guess it might be easier to find a...
  6. pwtomlin

    CF8M - A351 vs A743

    While there are some minor differences in the chemistry between A351 and A743, I would be surprised if the foundry in question actually had separate grades of CF8M for each spec. It is trivial to adjust the internal chemistry ranges to work for either specification. I can't speak to all the...
  7. pwtomlin

    induction vs eaf to produce billets for rebars

    There are plenty of steel foundries in the US running arc furnaces in the 10-12 ton range. I can't speak to a direct comparison between induction and arc furnace but as others have noted you can get away with cheaper raw materials in an arc furnace than induction.
  8. pwtomlin

    The Mystery of ASTM A487 Grade 4 Pressure Service Castings

    The austenitizing temperature and tempering temperatures listed are both given as minimums. You are allowed to go higher if needed. Classes B and D do not allow for air cool, hence the higher required strength levels. As metengr already said, the quench must take the temperature to below 500...
  9. pwtomlin

    PWHT loading temperature

    I have a question regarding the furnace temperature when a load is placed in it for PWHT. It is generically about any stainless steel, but more specifically cast pumps/valves in CA6NM (wrought equivalent 415). Metallurgically speaking, is there anything detrimental placing a load in the...
  10. pwtomlin

    When steel =Austenite structure

    See if it attracts a magnet.
  11. pwtomlin

    Intermetallics. Metal molecules? Need clarification.

    A conventional alloy, like steel, has a metallic bond that is characterized by an "electron cloud" where electrons are not strongly associated with a particular atomic nuclei. Intermetallics contain bonds that are partially metallic, partially covalent, and partially ionic. This mixed...
  12. pwtomlin

    Cast stainless standards

    The following alloys are considered to be cast equivalents to the associated wrought grades. 304 - CF8 304L - CF3 316 - CF8M 316L - CF3M
  13. pwtomlin

    PWHT Stress Relief Time for Q&T

    Just my two cents, The hour per inch rule is a pretty standard rule of thumb, but it's application is to ensure that the part is stress relieved throughout. Larger sections will reach the furnace temperature in the center more slowly than smaller section. The rate at which the center heats up...
  14. pwtomlin

    No allowable stress for alloy 20.

    I'm surprised to hear there's no CA15 or CA6NM available.
  15. pwtomlin

    Material Certifications

    I think what most people are trying to say is there isn't any reason asking for certs should cost you significantly more. I think there are two possibilities here. 1. There is some reason particular to your industry/suppliers/situation as to why they cannot easily supply certs for cold-worked...
  16. pwtomlin

    How to measure "1 in 20 parts"

    Some sort of log where you track how many are poured? Or possibly better, a log based on orders.
  17. pwtomlin

    Specialist vs. Generalist

    I'm reminded of a book (Guns, Germs and Steel, if my memory serves) where the author described a well-known sculptor who still planted his own crops so he could eat. Specialization, in general, allows people to spend more time working to their strengths and less time on tasks they do poorly at...
  18. pwtomlin

    career start advice

    I'm not exactly experienced; I'm working at my first "real" job out of college. But I went through a similar thing period not too long ago, and looking back on it I wish I had done things differently. I may be repeating a lot of advice in this thread, but it doesn't hurt to have good ideas...
  19. pwtomlin

    cryotreatment of 316L steel

    316L is primarily austentic, with some ferrite. I wouldn't expect this to change at low temperatures. If your 4340 underwent a vanilla quench and temper, I wouldn't expect any change in the structure (tempered matensite) unless you had some retained austenite. If you did, then you should see...
  20. pwtomlin

    A352 LCB Inperfections in a valve seat

    It's not that surprising to find porosity in LCB. If it is a gas defect, it could be a melting process issue or an issue of venting (particularly if the defect is located off a core). If it's shrink, the foundry should be able to do something about it from a gating/risering design aspect. If...

Part and Inventory Search

Back
Top