NON-DESTRUCTIVE TESTING 4

[loka23]

Hi,

Drawing callout material is 17-4 ph CRES per AMS 5643/H1025. Which non-destructive testing is better to carry like Liquid Penetrant testing per ASTM E 1417 or Magnetic particle testing per AMST E 1444 for this material.

Thanks,
Loka

 

[EdStainless]

How is the part made and what defects are you the most concerned about?
LP is strictly surface only.
MP will also indicate things just below the surface.
Neither will tell you anything about the interior.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[monkeydog]

Recommend looking into ASM Volume 11 for NDI techniques and capabilities.

 

[metengr]

Wet fluorescent MT.

 

[loka23]

Parts is made from bar with conventional machining. Drawing call out is 'Penetrant inspection per ASTM e1417, type 1 fluorescent Dye. I have attached picture.

 

[Ron]

Looks like you are only concerned about machining anomalies or surface cracks. Fluorescent LP or wet fluorescent MT as metengr suggests should be fine for this application and material.

 

[dik]

The attached was posted in a forum that seems to have disappeared.

https://files.engineering.com/getfile.aspx?folder=c13eb8eb-3086-47cf-8ccc-688feb540043&file=NDT.pdf

Dik

 

[WKTaylor]

loka23...

Magnetic particle and fluorescent dye penetrant inspection procedures can be successfully accomplished on 17-4PH CRES, any hardness condition.

The NDI procedures callout you outlined is incomplete, IE: (a) Liquid Penetrant testing per ASTM E 1417 or (b) Magnetic particle testing per AMST E 1444

DO YOU KNOW WHY????

When I specify magnetic particle and/or fluorescent dye penetrant inspection for Aircraft parts I typically do so as follows...

Fluorescent penetrant and/or magnetic particle inspect per MIL-STD-1907** Grade A.
**MIL-STD-1907 INSPECTION, LIQUID PENETRANT AND MAGNETIC PARTICLE, SOUNDNESS REQUIREMENTS FOR MATERIALS, PARTS AND WELDMENTS

This spec is applicable to materials, parts and weldments. It ALSO includes [as part of the Grade A, B, C, D system] all elements required for a successful NDI process callout: when-to, how-to, what-to, etc... and is very specific as to accept/reject criteria.

The 'how-to' ASTM specs you cited do NOT describe vital defect accept-reject criteria. MIL-STD-1907 lists very specific defect types/sizes/densities [#-per unit surface area] that are permitted within the grade category.

NOTE. I recommend a quick and dirty way to add a more rigorous/generalized accept-reject criteria, to the proposed callout (a) Liquid Penetrant inspect per ASTM E1417 or (b) Magnetic particle inspect per ASTM E1444., thus...

add...

NO detectable defects permitted during final NDI inspection after blending-out all defect indications to maximum limits as permitted by [drawing][repair data][etc].



Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[Ron]

WkTaylor....I agree with you except for one thing....the poster is not in the US and therefore MilSpecs do not apply. He has to specify to prevailing specs.

 

[WKTaylor]

Ron... may be, may be-not...

17-4PH CRES per AMS 5643/H1025
Liquid Penetrant testing per ASTM E1417
Magnetic particle testing per AMST E1444


Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]