17-7 PH (semi-austenitic) has Al precipitate while 17-4 (martensitic) has Cu; thus the aging behavior would be different. As mentioned by metengr, the initial state of 17-7 is also important. You have to see the cross section and see how the welding affect the 17-7 and 17-4 microstructure; I...
I have a forging cylinder block from a nonstandard PH/ martensitic grade. PMI results show 15Cr-5Ni-1Mo-0.8Mn-0.2V with 35-39 HRC. I plan to do the spark test or take out a core sample to decipher whether this is a PH SS or fully martensite. The bores in the block are washed out due to sand...
Hi,
The atomic packing factor or unit cell density would affect that too. BCC and FCC have different packing factors. Different chemistry within Solid solution (Fe with C and other alloying elements) would affect that too. You couldn't say the bigger the lattice, the higher CTE.
Check one of...
Thanks for your inputs. No, our inspector found it in China.
The sand intrusion is not only around the centre bore. See the attached picture for the moulding. They used what they called it urea! I'll try to get more info for the sand...
Hi All,
We faced a problem with a Chinese foundry on a precision casting: They poured the same part from CD4MCuN with no problem before but now they have this sand inclusion problem with A216 WCB (as shown attached)! I am wondering if any body has experienced this kind of defect and know the...
My observation:
I agree with crack initiation site. Also around that as you pointed out by red oval, looks like fatigue clamshell marking to me. There might be a porosity or casting defect that act as stress raiser and initiate the crack. Cyclic loading (?) assists with crack propagation till...
Your welcome. HVOF does not have superior impact resistance though but easily can reach 1200 HV. If you go that path let me know I have robotic HVOF:-)
Thanks Arunmrao.
We are trying to go with 30% Cr. I would expect martensitic matrix with CrC precipitates in the hardened and stress relieved condition. What is the acceptable retained austenite/pearlite for that? Of course if I need more corrosion resistance than wear, more Cr is needed in...
Hi folks,
I am writing a spec for purchasing A532 Class III high Cr white cast iron as the A532 is very general and I want to restrict the hardness and ITP requirements. What specific requirements you would put in the spec for this material? I know the general ones for casting but looking if...
Why Raman? Have you tried XRD? You can try combined EDS and EBSD as well on SEM.
By the way, I used Raman and its not hard at all. You just need to find the associated wavelength for Ni3Ti from references. Give it a try!
If you dont want anything in A532 range, for high temperature I would consider Ni-Mo-Cr alloys (Hastelloy B, C, etc.) or possibly Stellite/other cobalt based alloys.
Also consider hard facing (PTA or laser) with Stellite or WC base coatings.
I assume you welded with A106-P1 WPS! In my opinion, there wouldn't be too many other factors. You could weld P22 with 7018 and to CS but perhaps with a P11 butter layer, proper preheat and PWHT. See here also:
http://www.eng-tips.com/viewthread.cfm?qid=365137
In addition to what you said...
@geesamand Your welcome. I agree with you and @ jgKRI on creating a standard as I did it myself as well. Thats also recommended in SSPC SP COM. Make sure you add "Accepted" and "Rejected" pictures both in that. However, if you happen to face an inspector which couldn't distinguish between mill...
This was a headache for me at some point of time!Particularly if you have a customer who does not have a good knowledge of Metallurgy.
Unless you are working for pharmaceutical or some nuclear jobs, heat tints, chemical spots are more than ok based on unwritten industry common practices! You...
Metengr, thanks a lot for your input. May I ask why Inco 82? Unfortunately we dont have a procedure for that readily and cant machine down 1/4".
We do have ERNiCrFe-7 (Inco 152) and ENiCrFe-3 (Inco 182) though.
This is totally dependent on the design and also the materials you are using. EdStainless touched perfectly on the design. On the Materials side, if you are working with Metals/alloys/MMC, I would say tensile is more important. On the other hand, Ceramic/some PMC and CMC/powder metallurgy stuff...