Need to know :(1) geometry and dimension of pipe ( outside diameter and thickness) (2) steel grade of tube (3) autogenous welding or by filler?.
All these info are indispensable in order to understand which kind of NDT methode could be applied.
Ed,
I didn't refer to spectographic analysis apparatus such a - for instance- Thermofischer mod.4460 ( ex ARL) used for final heat analysis certified by steel maker where "precision and accurancy" is mandatory. I did talk about OES mobile and XRF mobile ( such as Specro )widely applied by most...
I think there no difficulties to separete 430 FR and 430 F by use MPI. Also the spark of MPI( Spectrum or ARL) is a little be different.In any case, the value of Mn is wrong. Normallly , value of is Mn < 0,5% in order to increase the resistance corrosion for free machining ferritic SS and...
Maui, all my evaluations was done considering the available information. Therefore, darkness or not darkness of micro cannot be evaluated if the time or kind of etching are not available. In any case, the structure of sample A is coming from a fast cooling + tempering. In my previous mail,I...
Maui, I was forgetting. In order to complete these evaluations, you should verify what both certificates of Supplier A and B declare about the hardeness and/or mechanical properties in delivered conditon , size and chemical composition as well. The hardeness you have found verifying steel A...
Maui, most of induction heating applications, require a condition of hardening + tempering heat treatment of steel in order to obtain a tempered martensitic structure whose Hrc value ( or Rp 0.2 an Rm )will depend on final use. The reason why of this structural condition were explained in my...
Micro A is in hardened + tempered condition and NOT in as rolled condition because this grade cooled after hot rolling shows a microstructure of perlite and ferrite. (unless a special cooling process had been applied) --- Micro B is in annealed condition or slow cooled after hot rolling. A...
Chonghm, 410 has a tempered martensitic structure. F6NM shows a tempered martensitic structure with a certain amount of stable austenite depending on its chemical balance and tempering temperature. This kind of austenite is a good "airbag " in some aggressive and cryogenic environments...
Excluding a high level of segregations , it's very unusual that this grade with C% lower than 0,03% and N < 0,01% is affected by carbide precipitation with a rapid cooling rate from 1050-1150° C and with the right soaking. I am a little be perplexed about the declared Nitrogen content ( N=...
Ed Stainless:in welded (fused ) austenitic structures, delta ferrite doesn't transform in martensite after cold working. Only austenite could have this behaviour. Probably, you are reffering to transformation of delta ferrite into sigma phase.
I suggest to verify the certificate: what is Sulphur content ??? Indipendently if 316 L or 316, if S% is very low ( < 0,01), machinability will be poor. On the contrary, if S% = 0,02-0,03 , machinability will good. Moreover, as EdStainless said, if the structure were a little bit harder and...
Rebars have basically same kinds of seams of other hot rolled round bars.
Depending on kind of seam ( as crack ,if you like ), it's more easy to detect by visual testing on large diameters than in small ones.
Typical surface defects of carbon steel depending on poor surface quality of...
Evaluations of Ed and suggestion of Metengr are right. But, do you think it wouild useful to know which kind of Ni-alloy ( or ASS ) are you reffering ?
General speaking ,temperature of 2400 F for most kind of Ni-alloy is exagerated and close to melting (2550-2600 ). At first plastic...
Thank you for your answer and I agree with your evaluation. I think a knowledge of Hc and magnetization curve would suffice because Brem depends on the magnetic circuit condition and could vary.
Hello,
there is a specific reason why for relay application of both ferritic SS or Si-Fe alloys, Br and Hc values are generally required misuring at the maximum flux density of 1 Tesla ( 10kG) instead of saturation flux density Bs ?
Only now I saw the picture.
Annealing temperature is too low for these grades: intermetallic phase could exist also on surface, not only in the core.
This cracks is typical of not complete cooling as I mentioned in my previous post. You must wait for before come out from water.
Metengr is right when requires more info.
However, if you are sure internal cracking is not caused by a wrong preheating process (i.e cracking before quenching ), the reason why large round bars fails is due to a premature coming out of the water quenching tank. These grades must be cooled...
Redpicker is right ! In my opinion, for sealing performances , it's better to talking about Rmax or Rt ( max peak-to-valley height ) than Ra ( Average roughness height ) . You have to evaluate that a isolated pit, scratches or dent may cause leaking in zones where these ones could happen...
During these last years, I found that there is a lot of different opinions about the use of "improved or enhanced machinabilty of austentic stainless steels according to Nace MRO175-2009. I'm talking to standard Astm 304/304L and 316/316L and NOT to free machining stainless steel as Astm 303.In...
depending on final use. In other words, a certain % of Ferrite could be useful for autogenous welding but if this % were little bit higher ,it could be deleterious for hot working ( forging , hot rolling .. ) , for highest polishabilty, in case of soaking for a long time at temperature in...
