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Service temperature is 650C (as I was informed). Of course size isn't typical for Laves phase and shape of voids is doubtful...

Dear all, Thank you for your reply! Yes I mean 347 steel, service time is tens of thousands hours. Of course it is very important to do examined area checking during work on site as well as select polishing/etching mode more carefully. I would like to clarify: it isn't carbides (these voids...

No it is replica surface, but I used DIC (Nomarski prizm) for 500x magnification photo. Too difficult condition on site to examine surface directly

Maybe I wasn't clear, but I did mean that these "features" are below pipe surface (I can see some bottom when I change focus. Silicon rubber was used for replica. I can say exactly it isn't remaining from cleaning (sometimes there are small drops of alcohol on examined surface, but it is clear...

Hello, The replica examination shows some cavities (acc. to focus changing) along grain boundaries. Electropolishing and Kalling's reagent was used in this case. I have some doubts about cavities formation reason. What is your opinion? Thank you in...

Thanks a lot EdStainless It is great if we have clear requirements for microstructure acceptance f.e. "unaffected structure" acc. to ASTM A923 method A or "no intermetallic precipitation' and etc. But requirement "adequate microstructure" isn't transparent...

Hello, There is very interesting requirements for duplex steel weld in EN ISO 13445-4 (PED: steel group 10 weld micro structure examination shall shows adequate microstructure. What do you think what it means? My problem: no any intermetallic precipitation, but there are some nitrides...

And photo at 500xhttp://files.engineering.com/getfile.aspx?folder=899adcc7-f1b7-4f85-bbed-86c6621c2ca8&file=500-2.jpg

Hello, Replica inspection of gas turbine blades was performed. I see some "strangeness" in micro structure. Please see attached (photo at 100x, photo at 500 in next message) Some precipitation along grains boundaries/in grains. Surface was cleaned carefully before replica... Is it possible so...

This pipe was damaged during removal from service. There are strong deformation line near OD surface and mechanical damage (like notching)of surface so identification of discontinuity isn't clear. I have attached other photo (with deformation lines, notching and cracks like SCC)...

Hello, We have examined SS pipe surface condition. There are some stress corrosion cracks on OD surface. But this subsurface discontinuity (please see attached file) is very strange. What is your opinion? I see the shape of defects like this in the first time in my practice. Thank you in...

Hello, Could you help me: what way is it possible to differ single creep cavity and hole from fallen carbide (at grains boundaries)? I have some doubt... Thank you in advance.

Thanks a lot! We have performed only hardness test (due to sample size). Hardness is around 125 HV10. Conversion in Rm (UTS) give acceptable result for steel S235, but as I understand in this case value of Rp0.2 (YS offset 0,2%) would be more significant... N.B. Could you please give some...

Hello, Could you give me some advice? Now I examine structural steel (S235) sample from fired construction. As I can see there is shperoidisation of perlite and some carbides along grain boundaries. Band structure is disappeared. Is it really possible this changing after fire...

I can't attach 2 photos. Sample No 2.http://files.engineering.com/getfile.aspx?folder=5e3b446f-65c5-4cf8-90af-524508cec324&file=Sample2.jpg

Dear colleagues, Could you give me any advice about evaluation of microstructure of steel 38MnVS6. Only ferritic-perlitic structure is acceptable. If sample 2 microstructure consists from ferrite and perlite (+sorbite?) microstructure of sample 1 consists from ferrite, perlite, bainite...

And one more comment: voltage 2B, current 0,18 A. No any jump on current/time curve.

What is interesting assumption! We use LectroPol5 (Struers) for etching (no "direct contact" examined section with electrode). We examine about 5-10 sample in day. Other sections were without any surprises. I think it can't be caused with etchant problem, but I can understand reason of...

I have attached photo for DSS weld. Etching time 2 sec (NaOH), magnification 1000. I think intermetallic phase is seen clearly. Hardness in this point was 305HV10 vs 245HV10 for BM.http://files.engineering.com/getfile.aspx?folder=d653447d-c872-4ce3-b8fd-2e586dde9417&file=2sec_1000.jpg

I have attached photo of SDD weld. If the first photo is weld surface, the second and this one is in 2 mm from weld surface. Welds was performed by SAW. It is local microstructure changing.http://files.engineering.com/getfile.aspx?folder=dcf93f9a-2fea-4f99-8a23-0656b033388f&file=SDD_weld.jpg