What’s up guys?!?!?! It’s Michael with Michael Talks Metal back for part 2 of our series’ 2nd installment of How to Read a Material Test Report.
We’re back for the one hundred and twenty second time, picking up where we left off last week in the middle of a type 321 stainless steel certification.
If you have not yet seen last week’s video, click here…..
Our next section requires a bit of explanation about a corrosion test, so here goes
Type 321 and its higher carbon version..321H, use an addition of Titanium to preferentially form carbides that otherwise would form with Chromium at grain boundaries. If Chromium carbides were allowed to form, it would have a negative effect on the corrosion performance of this alloy. In order to confirm that this alloy has the desired corrosion resistance, it is subjected to an intergranular corrosion test.
A sample is first “sensitized”….. a heat treatment that would promote the formation of any harmful chromium carbides at grain boundaries.
The sample is then exposed to a very aggressive corrosive media of boiling sulfuric acid and copper sulfate to attack the sample at the grain boundaries.
The sample is then bent 180 degrees and examined for any evidence that the acid had initiated cracks due to corrosion. When no cracks are observed under magnification, the sample has satisfactory resistance to corrosion under these extreme conditions.
Our next section contains various statements documenting that the material was solution annealed and verified free of harmful grain boundary carbides.
Macro and micro etch testing confirms a sound structure.
The reduction ratio is the cross section area of the cast size to the area of the hot rolled bar size.
Last in this section we have a statement that the material is DFARS compliant.
Next section indicates that each piece of the material has been verified as the correct alloy prior to shipping from the mill.
Page 3 continues with additional statements indicating all manufacture was in Italy, no weld repair was made on material, and that it has not been contaminated with Mercury or by any radioactive substance.
Last we have additional certification to the EU Pressure Equipment Directive and a Fraud and Falsification statement.
That’s gonna wrap us up for today as it looks like we are out of time so please don’t forget, ever, NEVER forget to CHECK THE SPECS!!!! This is Michael with Michael Talks Metal, Michlin Metals is a full service supplier and distributor of all things metal and steel check our website www.michlinmetals.com for more details. Thanks again for watching. Missed last weeks’ video? Click here. Still here and haven’t subscribed? Click here to help support the channel. Thanks for watching, this is Michael with Michael Talks Metal, see you next Thursday same time, same place. I’m out.