today's topic is metal identification so you're in a manufacturing setting
chances are you could be doing some sort of a metal maybe the the subassembly you
may be making that subassembly maybe in just dealing with the raw material going into
that product that that you're manufacturing so you kind of have to have some
ideas about the metals at you dealing with today we're going to do just a very
brief topic of metals wanna talk about some items you should know and a few
test that you can do real quickly to see something to see what type of metals
that you're dealing with so we'll go right into some metal terms having a
basic understanding of different types of metals present in the shop
environment or manufacturer environment is very important to be an efficient worker
because if you're trying to deal with aluminum and you go to keep going over
and picking up carbon steel you are not going to be very efficient
but the difference between aluminum and carbon steel can be easily be to be to be found to be
seen
so you shouldn't make that mistake over and over if you kind of know some of the rules
behind it
many metals have the distinguished by their physical properties such as color,
weight, internal structure, even surface appearance simple tests can be done to
aid the craftsperson in metal identification. Metals can be classified by
either as ferrous or non-ferrous. We will cover those what each one of those is in
a second. Metal handling of metals I'm sorry material handling of metals will
vary by company according to the company's standard procedures and
policies and sometimes quality control. A ferrous metal
contains iron even though that I may have other elements or other other
metals added it has iron in it. So anytime that you know of iron, its ferrous no
matter how much iron is there the properties can be altered to meet
specification some of those includes cast iron, carbon steel, as well as the
typical
tools steel that everybody uses for tools and generic generic steel making.
Then you have the non-ferrous metals which do not contain any type of iron they're
they're usually
non-magnetic means that they the magnet want won't touch them and they are more
resistant to corrosion since they don't have the iron aspect to it, they are more
resistant to corrosion include aluminum brass and copper. Continuing with metal
terms, pure metal as a single element metal. Pure means that there's nothing
else added it is just that type of metal you know so there's nothing really else
added but if you have a mixture of two or more than is called an alloy and
alloys are created when specific properties are desired that pure metal
does not exist sometimes you have aluminum alloys lot of cars that we have
the rims on the car you want lightweight but you want strength so you
have an aluminum alloy to make up your rim. Ferrous metals can
include mild steel which is the most utilized ferrous metal. It is composed
0.15 to 0.3% that is not 15% percent that is 0.13 percent now
that's a very small amount of carbon with iron carbon steel is composed of
you have mild steel then you have carbon steel. Carbon steel does have a little bit
more carbon its 0.5 to 1.5% carbon steel is extremely tough allowing it to be
hardened and tempered. Steel which is a form of iron contains somewhere between
0.03 to 1.7% carbon just a generic common term called steel will fall
in and out of that range. Then you have stainless steel. It is an alloy of iron nickel and
chromium which has its very high resistant to corrosion since the
properties of it are allowed to be tough as well as stain resistant and or
corrosion
existence resistance so hence the name stainless steel since it's very hard to
actually stain and it's very tough so stainless steel is kind of how the
name came about six types of metals service sites there there are six types
of tests for medals will only discuss the magnetic and the spark test but but
there are others such as appearance, fracture, magnetic, chisel, spark, and torch
you'll see in the video that you watch the videos of the magnetic test
which is attached please go watch that video you can kind of see the appearance
of each one of them such as looks the sheen, maybe even the feel and the weight
you're holding the difference between aluminum and the high carbon steel you
will be able to see that there's a there's a difference in weight they're kind of all
falls inside their appearance. The magnetic test uses a magnet to see if
the metal has an attraction a strong attraction is usually an iron alloy or
pure iron of some sort
pure nickel stainless steel carbon still a slab attraction could be called to
call model which is high and nickel alloy of non and non-metallic metals
such as copper aluminum zinc and some other precious metals such as titanium
you'll see that on the magnetic slide as well as a go over and look at the video
on the only a few minutes along the magnetic test of different types of
materials another test that we have is the spark test it is a simple
identification tests used to observe the color spacing and quantity of sparks
produced by grinding of the metal. Spark test requires some practice to in order
to have reliable results because if you're putting you about the pressure I
put too much pressure on it you're gonna have too much sparks and then therefore
it's not going to show off the material or you would have not enough pressure on
it you better have enough sparks to be able to show off the material either so it takes a
little practice to get it right and you need to make sure you are using the same amount of
pressure for each
each metal or type of material being used.
Of course determining the grades of the metal by spark test is just not
practical so looking at a low carbon steel which is 0.3 percent mild steel
will produce sparks in long yellow orange streaks that may erupt in the white
forked sparklers and this is what you see when one has been in sparked I'm going
to show the video in a second so we're gonna go over this medium carbon steels
0.3 to 0.6% exhibits increased forking from low-carbon produce a wide range of
spark links and or more near the actual grinding over its means that are closer
than they're not so far away there closer than you have carbon steel
producers and increase the amount of bright yellow orange sparks high carbon
steel has a lot of carbon in point six to one percent. And then you have aluminum which doesn't create
sparks at all.
Stainless steel will give off a few little sparks depending on how much carbon is
in that you see in the video the stainless steel we
have has very low carbon you don't you can kind of see very very few sparks and
then you've got copper which does not create any sparks at all
when tested so ok we'll move over the video and start the video the video
online or have some some music and and some talking there real quick so there's
the grinder that we used for the video we did some practice to make sure we got
the the the the pressure down right and the first one you see is aluminum and
listen the video is pretty loud so you can't hear me talk about it but aluminum, you don't see any
sparks do you so in the spark that you buy saw was something that was on the
grinding wheel itself so so does sparks that's just kind of the the characteristics of
aluminum. It's also very sheen is also pretty light ok here you talked mild
carbon steel. Mild carbon steel you see the orange to a yellow sparks with the white
sparklers see how far goes off you can see the sparklers going there I get a
handle on the second you kind of see it but you can see the the white sparkling
forks sparklers at the end you can see them right there toward the end there nice forks
next one stainless steel should have very few sparks you can see it there
there's there's not as much as the other ones it all depends on the type of iron
content that you have but you can see here very little sparks long red
streamers long orange and yellow streamers with very little fork in the
end very typical of stainless steel.
next you have copper and you see there pretty much nothing there. Copper does
not create any sparks when tested. The little sparks that you're seeing are probably
metal residue left inside of the grinding wheel and coming out as we apply
pressure with the copper but there's nothing no real sparks there. Of course you
can see by the appearance too that it is copper. Here's a high-carbon steel
produces increased amount of red and orange sparks look at that as you can
see the increase of it does definitely there in the middle of the plume and it's
got the the white sparklers and there but it's the volume you can see the
volume from the from the amount of carbon steel is as much increased the
amount of there in the middle of the sparklers are much much greater. Titanium
we don't really talk about titanium much, but look at this
titanium. Wow bright white sparklers at the end very dynamic very easy to
identify titanium from any other type of metal really pretty easy to make that
make that determination hey that is titanium you won't be quizzed on it or
nothing on the the exam but I wanted to show titanium. Of course you see I was
able to secure small little piece for demonstration today
oK so that's our spark tests. Moving onto a metal terms with on getting some
stainless steel stainless steel is as a big metal that with that you use in
manufacturing especially because of its properties. It's tough to corrosion
it's hard to stain but still very durable now keep in mind though
stainless steel is more expensive than normal tools to a low-carbon steel it is
very expensive and sometimes it's not found in manufacturing because of that
depending on what's being made but typically somebody wants a part to
last they're going to use stainless steel and if you do I want to know
there's the there's a there's different types. There is the austenitic which is
created by adding nickel or manganese and nitrogen this type
has ability to be welded and formed. It is most frequently used in which is the
most frequently used type of stainless steel there is then you have the ferritic
it's chromium based. Ferritic steel possesses a minimum less than 10%
in quantity of carbon and have a similar microstructure to carbon and low
alloys given the absence of toughness and welds. Ferritic steels are
suitable to use in thin segments only when you have of course these words
don't get any easier to say you have the Martensitic steel like ferritic
stills martensitic steels are chromium based however they contain a greater
level of carbon you have up to 1%. Duplex are half ferritic steel or 50% and the other half
is austenitic stainless steel so duplex
steels have a higher strength and are resistant to stress, corrosion, cracking,
precipitation hardening sorry pH is the addition of copper and aluminum which
creates a PH steel which has a very high strength level so today we've gone over
understanding of metals trying to find ways that you give you some basic terms
to help you manufacturing this is just a small little tidbit that we have in our
in our course the videos are there to help you should have a video for a
magnetic test as well as the spark test but look at the while you are
doing that look at and you can see the the types of appearance you better see
the different types of bands from smooth or rough to a grey or shinny material
into a copper and of course to a titanium so you will be able to see different types of
metals right there should help you go a long way information here today
should help you with also your your exam and quiz that you have at the end of the lecture
So good luck!