What’s up guys?!?!?! This is Michael with Michael Talks Metal back for number 115 to pick up where we left off last week with a deep dive into a mill certification of an aircraft quality alloy steel. Let’s do this!
If you have not seen part one…click the card right here now (or just click here) and remember, again, that today, we’re talking about how to read an MTR aka a Material Test Report. For the fully annotated test report click here.
Our next section has some results of tests performed to determine the actual grain size of the material. The previous section confirmed a fine grain size based on chemistry and this test has the actual result. A measured grain size is required by some specifications and others only the aluminum content. Both are reported here to comply with the various specification requirements.
Next we have a full report of the Jominy Hardenability that shows the heat treating response of this material under standard test conditions. Specifications may have requirements for minimums and or maximums at specific points. Some mill certifications would only report the specific points required to show conformance to the ordered specifications. In most cases this is a calculation made from the actual heat chemistry.
Here we have the results of the macro etch testing…. a test that confirms that the structure is free from injurious visible physical flaws. Multiple tests are performed to verify soundness from the first to last material cast. Ratings for the three characteristics S,R, and C with 1 as the highest quality rating.
Next we have the MAGNETIC PARTICLE TEST that shows the results of testing to assure the microcleanliness of samples to aircraft quality requirements. In this instance, the mill has reported testing and conformance to both AMS 2301 and the more stringent AMS2304 quality levels.
The next of the reported tests is to determine that the degree of decarburization that has occured in manufacture is within specification limits. In this case the depth has been determined by examining samples under a microscope and the depth from the surface measured.
Last we have a hardness test to confirm the material meets the restrictions in the ordered specification.
Well it looks like we are just about out of time for today, so stay tuned for next week’s conclusion and don’t ever forget to…..CHECK THE SPECS!!!!!!
Michlin Metals is a full service provider of stainless steel and other aerospace metals. Any more questions please visit our website www.michlinmetals.com
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