A Niton XRF metal
analyzer used in metal distribution
An article in 2012 about
a Naval supplier misidentifying materials prompted the discussion internally
about what procedures and services we could implement in order to remedy a
situation like this. It offers peace of mind in knowing that the material you
are buying is actually what you are buying. Without this high tech piece of
equipment, you would have to depend on the reliability of your supplier and
their entire supply chain to get it right every time. It is simple math that
the more products that are handled, the greater chance for misidentification.
Positive Metal
Identification (PMI)
Another addition to
our services offered is the PMI of your material. You can request a PMI, which
is a Positive Material Identification, of the shipment. This will ensure that
our internal material traceability is verified. A report of the PMI check with
the composition, as read by the Niton unit, will accompany the shipment. Depending
on the item and quantity, PMI reports can be generated for as little as $50.
This is a very small insurance to prove the material identity, traceability and
pedigree.
The PMI report
documents what heat was evaluated and makes an identification of the material
grade. The report may also include a Purchase Order number and part number. The
Niton unit presents the operator with a grade designation based on criteria of
the composition measured. While the composition it measures may not fully
reflect the results found in a laboratory sample or as the mill sheet reports,
the elements are used only to classify and confirm a materials grade or alloy
designation. Any elements that are to be reported need to be established at the
time the PMI is ordered.
While the accuracy of
the unit is quite good, the results are only as good as the sample it is
reading. A clean and bright surface should be used, free of contaminants such
as oxides and materials that may transfer on to the surface. With some samples
it is not possible, due to cosmetic or tolerance reasons, to attain an optimal
reading. These potential samples usually occur when sampling finished parts,
tube or pipe that does not have a cut end large enough to sample. Scotch-brite
has proven effective to brighten a surface on bar, sheet and plate, but again –
for cosmetic reasons this may not be allowed for uniformity of the finish. On
scaled or oxidized items, a clean emery cloth or an abrasive grinder will be
used to create a suitable sample area. Unless proper cleaning is specifically
allowed, the chemical results may show an element out of tolerance. It should
be known in advance that the PMI composition should not be reason for
rejection, unless a laboratory analysis is performed after to verify any non-compliance.
An integral part of our quality system
The equipment is
utilized as a screening process of incoming materials. Materials are sampled as
they arrive to ensure that they are properly labeled from the mill. This
procedure during material receipt keeps unknown material from entering the
facility stocks. Older stock that has not been checked already is verified
before shipment and marked as being evaluated. These procedures ensure
materials are sampled at least once through the system before shipping to your
facility. This is only a small part of our commitment to quality.
Reverse engineering a
component
The Niton XRF unit can
also be utilized to identify materials used in service as well as reverse
engineering an old part. Half the battle of a new material recommendation is knowing
the current materials’ shortcomings. Once you can establish what materials are
being used, it becomes simple deduction to determine other materials more
suitable or capable of handling an environment. It is a simple tool that can be
part of a failure analysis, with a simple determination of what the material
actually is comprised of chemically.
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