SA105N Flanges - Fine Grain Practice 4

[Krausen]

I believe this has been posted before, but I have not seen a satisfactory response. How does one go about ensuring a SA105N flange is produced to a "fine grain practice" in order to meet the impact test exemption of VIII-1, UCS66 for these under Curve B?

 

[SnTMan]

Krausen, the usual way would be to, first, specify fine grain practice on the PO and second, to insure it is reported as so on the MTR.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Krausen]

Thanks SnTMan. Is there an industry standard that can be referenced to vendor to ensure "fine grain practice" production for CS forgings/flanges?

 

[Christine74]

See here:

https://docplayer.net/48868523-Ncpwb-technical-bulletin-may-2016.html

-Christine

 

[Krausen]

Much obliged, Christine74

Tolerance is the virtue of the man without convictions -GK Chesterton

 

[SnTMan]

It is specified here and there in the ASME product specs. For a single example, SA-20 states "5 or higher (finer)".

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[EdStainless]

I don't know where ASTM/ASME stand on this, but the AMS aerospace specs have all been updated to allow meeting fine grain by measuring or by chemistry. Considering that the measurement is actually of the 'prior austenite grain size' the chemistry is a more reliable indicator.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[SnTMan]

Without dragging it back out, SA-20 has some alternative language about aluminum content or some such...

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Geoff13]

If your flange suppliers consider FG to be special order perhaps getting an off-the-shelf flange, like SA350-LF1, will be cheaper.

 

[Cobra17]

Alberta has an information bulletin regarding the subject (see attached)

Documentation Required for Flanges Produced to Fine Grain Practice
It should be noted that since the SA-105 material specification does not provide a definition for ‘fine grain practice’, Figure UCS-66 General Note (e)(2) refers to SA-20 for its definition.

In order for SA-105 flange material to be acceptable for use as having been produced to fine grain practice, the requirements of SA-20 §8.3, ‘Fine Austenitic Grain Size’ must be met. It is not acceptable for the material test report or any separate correspondence or certificate issued by the material manufacturer to simply indicate that the material was produced to fine grain practice. The material test report issued by the material manufacturer is required to be marked with one of the following, to the satisfaction of the Authorized Inspector:

 Indication of a McQuaid Ehn austenitic grain size number of 5 or more for the heat, as required by SA-20, §8.3.1
 Indication of a total aluminum content of 0.020% or more by heat analysis, as required by SA-20, §8.3.2.1
 Indication of an acid-soluble aluminum content of 0.015% or more by heat analysis, as required by SA-20, §8.3.2.2

 

[SnTMan]

Cobra17, nice exposition, thx

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Morcuse]

Refer to recently published PVP2022-84867 "Flanges Impact Testing Exemption Assessment" for more information.

 

[Krausen]

Refer to recently published PVP2022-84867 "Flanges Impact Testing Exemption Assessment" for more information.

Very good, thank you Morcuse

 

[ElCidCampeador]

My AI, acc. to this problem, answered me as follows:

-For MDMT -18°C and warmer, if flanges are standard acc. to B16.5 or B16.47, UCS-66 (c)(1)(-b) applies, so as-forged condition, without grain issuee, is sufficient.
-For MDMT between -18°C and -29°C, fine-grain practice is required and yes, according to note (e)(2) you must refer to SA-20 and its conditions. "Fine grain practice" only written on MTR, without any indication about Al% or grain size is not sufficient.

Please notice that if A105, in any condition, has impact test certificied @ MDMT, any discussion here doesn't apply because you do not have to apply anymore UCS-66 exemption.

This is what my ASME inspector told me: actually this means that requirements of SA 20, for standard flanges, are indeed applicable only for MDMT between -18°C and -29°C (@ higher temperature, as forged condition is enough)

 

[jmec87]

Is there a significant cost advantage or other advantage to using fine grain SA105N rather than SA350-LF2-Cl1?

 

[weldstan]

Fine grain SA 105N does not equate to SA 350 LF2 in terms of toughness. There is more to toughness than fine grain melting.