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XRF results, confusion in the form of Excell spreadsheet, Help ID this material.

SShep71

Hot Rolled
Joined
Sep 17, 2014
Location
San Diego, Ca
I had a lot of metal samples scanned a while back with an XRF gun. I am going though the results and while most have compositions that match, several have "ODD" compositions. One I am looking at right now.

98.515 Fe
0.737 Mn
0.32 Cu
0.161 Ni
0.12 Ti
0.096 Cr
0.031 Mo

This is a solid 8" diameter piece that is over 72", I need to make some gauges out of it but I want to make sure this stuff isn't just going to walk all over the place after final machining.
Does this data make any sense, I cannot seem to find a comparable material with similar chemistry ?
 
No I don't have the gun anymore, I had a guy come up for the day. I sanded the material down to shiny metal before he shot the test.
 
Those results indicates likely scrap re-melt steel. But without a carbon and phosphorous readings (you won't get that on a typical XRF) pretty hard to tell what it is

I get similar result from checking samples at work (we have a light-end lab XRF). Many of the minor concentrations you see are erroneous - unless in the hands of a experienced tech, XRF can be very misleading and the raw data needs interpretation. "One shot and read" like a scrap yard gun is really crude. Our machine does a large number of samples over a period, then performs a great deal of processing on the results. Even then, we don't get perfect correlation to our standards (very accurate alloys we check against). If we care, we get an fire assy done. In reality, results are not absolute, but a statistical probability of likely concentrations.

Cut a piece and turn it - that will tell you a lot.
 
just the first two get you to 99 1/4 - and you are not reading carbon - which could be anything between 0.15 and up.

Here are contents for 4142

4142.jpg
 
Can you spark test it to get the approximate carbon? Otherwise drill it and send the chips for LECO C/S.

Mn is right for 1018 or similar grades, 0.737 Mn. Ni, Cr, & Mo are all at residual levels. Cu is a little high, but that could be from the precision of the XRF. The Ti is a head scratcher - maybe some sort of microalloy addition to improve strength?
 
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The Ti is what has me guessing as well, I am looking at the spread sheet and element composition and everything else is within limits for the other samples. There are several that came up as *No Match* "Fe/CS"
 
So - Last guess is that this is a 10B22 grade. XRF would not see boron and would not be calibrated for a Ti addition, so a 0.03% Ti might be read as 0.12%. Trouble is a boron addition on a non-alloy bar at 8" dia. would be pointless. Unless the mill was getting rid of surplus as no-grade 8"... Again this is a last chance WAG.
 
Without knowing what type of instrument, or what the XRF was calibrated for, what kind of LODs and LOQs you can expect, etc. it is not possible to tell you if the results make sense.

Shave off a bit and send it into a lab for ICP-OES or ICP-MS analysis if you really want to know for sure. That amount of iron may be problematic, though. XRF is still in its infancy compared to other, more robust, methods. I had plenty of interference issues when validating T-XRF for wastewater treatment use (trace elemental analysis application for regulatory compliance).
 
I am pressed for time so this piece (and several others) are going to have to get put aside or reserved for non-critical jobs. Rack another stick of material up to "30 seconds with an engraver could have prevented this". Mark your material guys and gals. Not just a sharpie mark, don't just tape the paperwork to the piece. Hard engrave, both ends and the middle. If you cut a piece off, re engrave the drop. A dedicated Dremel engraver left at the band saw with an old piece of carbide (mine is a snapped off 1/8 endmill that I sharpened to a point) will cost you nothing compared to the cost of having mystery metal hanging around. Paperwork stay in the office, gets a serial number attached to it, the serial number gets engraved on the material as well as the length, diam, and type. I can pull up a spread sheet on my phone at any time and look at what material I have, on what rack, and know all the critical information. No standing there scratching my head to try to figure out if I need to buy a piece.

Just my way of doing things, not the right way, not the wrong way, just my way.

Be kind, please rewind.
 








 
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