<Basic
Welding Terms - Part-2Non Ferrous - Does not come from iron ore.
It is mined pretty much in its true form such as copper, aluminum, nickel etc.
Nozzle - A brass attachment that is about three inches long and
shaped as an open cylinder. It is put over and insulator (to keep the nozzle from
being electrically charged which would short out on the PARENT METAL and shock
the heck out of someone not using a glove.) and seals at the top giving the shielding
gas one direction to go
out over the weld. It is real important to
continuously clean built up SPATTER from out of the NOZZLE. Anti-spatter sprays
and dips help keep the spatter from sticking to the inside of the nozzle which
blocks the SHIELDING GAS. Open Circuit - Cross your arms across your
chest. Now uncross them. When they are crossed, they are like a "CLOSED CIRCUICT."
When they are not crossed, they're like an open circuit. When the switch on the
welding machine is open, it is not completing the circuit, therefore electricity
can not flow. When it is closed, the switch joins the two conducting parts
completing the circuit, allowing electricity to flow across. Oscillate
- While dragging (back hand) or pushing (fore hand) the weld PUDDLE, you oscillate
by moving side to side. (Think of an oscillating fan.) This feathers, or washes
in the sides of the PUDDLE into the PARENT METAL. Ovens - see POROSITY,
and also check out the ovens on this site. Overfill - Similar to
overkill, many welders think the more the weld deposited, the better the weld.
Overfill is a waste of time and material, and can weaken the steel by placing
too much heat on the joint. (Opposite of this is UNDERFILL) Parent Metal
- also called "base metal", this is the metal or steel that you
are actually welding on. Peening - When you're mechanically working
the metal, you are peening. How do you mechanically work it? You get a beater
(hammer) and beat on it. What it does is release stresses in the steel. Use
EarPlugs! Penetration - Is the FUSION or depth into the PARENT
METAL from its surface, or the amount of FUSION through an open faced joint.
Plastic Welding - Yep, there is actually plastic welding. It uses several
different processes. Saw one in the field with a hot air gun that almost looked
like a hair dryer, and a long plastic weld rod.
Plug Weld - Say you
have two pieces of steel you want welded together. One has a hole in it, the other
doesn't. You lay the whole piece on the solid piece, and then weld in the hole
making sure you burn into the bottom piece. You can either make one weld at the
bottom of the hole (properly TIED-IN of course) or fill the hole in flush. I
spent two full weeks at a power house plugging holes. After it had been damaged
by a tornado, it was decided to weld all the gusset plates and connections that
were usually bolted. They then had us remove the bolts and put plugs into the
holes, which served no structural value, but were for aesthetics only. To this
day, I wonder why the heck they didn't just leave the bolts in! And I still can't
believe I repeatedly risked my life working in very high, awkward situations,
just to plug a dad gummed hole! Polarity - Back in the day, we referred
to the flow of current as STRAGHT POLARITY and REVERSE POLARITY. In SP, the electricity
flowed out of the STINGER and into the WORK CLAMP. In RP, the electricity flowed
out of the WORK CLAMP and into the STINGER. For a better explanation see
DIRECT CURRENT ELECTRODE NEGATIVE and DIRECT CURRENT ELECTRODE POSITIVE, what
we now use instead of POLARITY. Porosity - Referred to as worm holes,
these are gas pockets trapped in the weld. A couple of reasons would be from not
enough shielding gas in MIG, or moisture in the FLUX in 7018 low hydrogen rods.
The moisture can easily be prevented by using one of Keen's rod ovens.
See How to Store Rods Properly
http://www.keenovens.com/articles/store-rods.htm Ports
- In a mig gun there are small orifices (holes) that allow the flow of shielding
gas. The NOZZLE then directs the gas out over the weld PUDDLE. Positioner
- These are usually found in the bigger more prestigious fab shops. They can
turn, tilt, rotate, revolve and that allows you to make most of the welds in the
flat or horizontal WELDING POSITIONS which is really NICE! Pre Heating
- Some steels will accept the weld better, and the weld will be more sound
if the steel is heated before being welded on. This is especially true up North
in the winter time. Adding hot filler metal to cold steel is NOT a good idea because
it could cause the steel to become brittle and crack. Most of the time
the weld specs will tell you what the PRE-HEAT temperature is. One way of checking
the steel is with heat pencils which melt at certain temperatures to show when
the right heat is achieved. See CRACKING. Post Heating - I know,
I know, it ain't in alphabetical order, but I just couldn't put POST-HEAT in front
of PRE-HEAT 'cause it just doesn't work that way. Post-heat is of course, exactly
what it sez
heating it up after you have welded. Actually what you
are doing is controlling the cool down of the steel. Instead of letting it cool
down on its own, you heat it periodically and slow down the cooling process. This
is more for the exotic metals, as a structural Iron Worker I never had to do any
post-heating. However, when working in a shop a few times on cast iron, I had
to post-heat the cast iron to make sure it didn't crack. Here's a great
site from Lincoln on cast
iron welding. Puddle - Ahhh, the puddle. My welding instructor
used to drill into my head "RELAX your hand and WATCH the PUDDLE!" The
PUDDLE is the same as the WELD POOL. It is the molten filler metal that is combining
with the PARENT METAL. You have to see it and manipulate it to make a good weld. The
following excerpt is from TheFabricator.com
I
learned welding from two of the best in the business. Phil Newell yelled in my
ear, telling me I was never going to be a welder because I didn't practice enough-scared
the hell out of me. Mike Waldrop was a laid-back, easygoing, go-have-a-beer-with-me-after-class
kind of guy. I learned all sorts of tricks of the trade from both of them and
am forever grateful. They had different teaching styles, but they both taught
the basics:
RELAX YOUR HAND WATCH
THE PUDDLE Correct rod angle Correct travel speed Correct amps PRACTICE,
PRACTICE, PRACTICE! Quench - Rapidly cooling the steel to make
it harder. The steel has to have enough carbon in it for it to harden. Mild steel
can't be quenched to harden it because it has only .33% carbon in it. You need
about .70% to be able to harden by quenching. You are changing the crystal structure
from one atomic pattern to another. I've touched on this in http://keenovens.com/articles/heat-treating-2.htm. A
very good article on hardness and quenching can be found at eFUNDA's
engineering company site. Radiation - The welding arc puts out
radiation that you must protect yourself and others from. It is important that
you announce to others that you are preparing to strike and arc. In my shop we
holler "WATCH YOUR EYES!!!" That means it's up to you to look away from
whoever just said it. See FLASHBURN. Besides burning your eyes, the radiation
emitted from the arc can also burn your skin similar to a sunburn. You should
always cover your skin with dark colored cotton, wool, or leather. Repeated radiation
burns of the skin can result in skin cancer later in life, which is a very fast
growing, and deadly form of cancer. Radiography - Is the enemy of
bad welders. The weld is x-rayed and it will show even the minutest WELD DEFECTS.
(Slag inclusion, porosity, or undercut!) Rods - See ELECTRODE.
What we call electrodes in the shop or field. Nobody asks for more "electrodes",
they ask for more rods. Just like the actual term is "SMAW", in the
shop or field we call it "Stick Welding." So, if I'm "stick welding",
I'm using "rods." Root Opening - If you're welding two
plates together that are beveled, (see BEVEL) the root opening is the gap separating
the two plates. Root Penetration - How far the FILLER METAL is
penetrating into and through the ROOT OPENING. Here's a nice illustration from
Integrated
Publishing
Safety - ahhhhh Grashopper, this is absolutely
the MOST important part of welding, the safety of you AND others! Welding
has all kinds of inherent dangers. I've had quite a few smashes, bumps, bruises,
cuts, scrapes, shocks etc. But the worst was when I was knocked off of the 3rd
floor of a building (well, actually right below the 3rd floor, but who's counting?)
and shattered my ankle. However, although dangerous by nature, it can be
relatively safe if the proper safety practices are followed, AND common sense
is used. One of my pet peeves is all the different shows on TV that show
people blatantly disregarding safety. All it takes is a split second to be hurt,
or hurt someone else. And usually it would've just taken a moment to do it right,
or get the right tool, or protective gear. There are all sorts of books,
articles and guides to welding safety. Just remember that you can get yourself
and others hurt or killed if you don't learn and follow these practices. Two
of the accidents that I hear about almost every year are eye injuries (from not
wearing the proper protective devices) and people hurt or killed from welding
on or near containers. Welding/Cutting on or near a container that you
don't know about is dangerous in three ways
It
can be toxic, flammable, and or explosive. NEVER, NEVER,
NEVER weld on a container that is not either new steel, or has been cleaned
and safety certified. I don't weld on used containers PERIOD. Ain't worth
life or limb to make a dang barbeque! Also, on cars or trucks, gas tanks
should be removed or made sure to be full so they don't explode. If it is full,
the most it could do is burn. If there are fumes and a wayward spark, or current
traveling the wrong way, you might just wake up DEAD! http://www.hobartwelders.com/pdfs/ms199776b.pdf
http://www.millerwelds.com/resources/safetyresources.html
http://www.lincolnelectric.com/community/safety/ Seam
Weld - The seam is right where the two plates, strips, etc. touch. It is important
that you get half of the WELD POOL on each side of the seam. In ARC GOUGHING
(where you are cutting an existing weld out) you want to cut through the weld
until you see the seam which will appear as a crack. This is where the two pieces
meet. The cut is on the weld with little damage or heat to the plates.
Semi-Automatic Welding – MIG is an example. The machine runs
the wire (FILLER METAL) and supplies the SHEILDING GAS automatically, but it takes
a person to pull the trigger and manipulate the gun to make the weld. Seventy-five
/ Twenty-five – 75% Argon / 25% Carbon Dioxide, see SHEILDING GAS. Shielded
Metal Arc Welding – See also STICK WELDING. SMAW, is the process where
we use ELECTRODES or RODS. Although some of the other processes are more efficient,
there are some jobs where SMAW is the most practical, like climbing around on
a high-rise office tower, shopping centers and large spread-out structures. See
the following for advantages/disadvantages involved… http://www.thefabricator.com/ArcWelding/ArcWelding_Article.cfm?ID=584
http://www.thefabricator.com/ArcWelding/ArcWelding_Article.cfm?ID=3 Shielding
Gas – Gases such as argon or helium are inert, meaning they will not
combine with other elements. This makes them good for keeping atmospheric contaminants
out of the WELD POOL. Carbon Dioxide is not inert, but effective and used in MIG
either by itself, or mixed with inert gasses such as 75/25. Carbon Dioxide
gives a deeper penetrating weld, while 75/25 gives a smoother appearing bead and
less SPATTER than pure CO2. Skip Weld – A sequence used
to control warping (distortion). Once on a parking garage there were big beams
made of concrete with steel gusset plates on each end to be welded to gusset plates
on the columns. Concrete is never completely cured, it has moisture in it. If
you get a cutting torch close to it, or excess heat from welding, it will blow
up and send little concrete shrapnel shooting out like a dad gummed fragmentation
grenade. If we woulda' welded those plates solid, it would've blown concrete
out from around the plate and weakened the connecting points big time. So
instead, we skip welded the plates. We'd weld a couple of inches at the top, couple
at the center and a couple at the bottom. We'd let that cool, and then do it again
until the plate was welded solid. It's all about keeping it cool dude. Slag
– when the FLUX on a welding ROD melts it produces the SHEILDING GAS
to protect the weld, and then forms a hardened protective coating over the weld.
This has to be chipped off and thoroughly cleaned, usually by brushing. Slag
Inclusion – If you don't properly clean the SLAG from a BEAD, you run
the risk of it becoming part of the weld when you run the next bead. A good welder
will generally burn it out on the next pass, but if not, there will be a chunk
of slag in the bead which leaves a weak spot. Slag inclusions are one of the main
WELD DEFECTS. Slot – Slot welds are just like PLUG WELDS
except instead of being round, they are elongated. (Long and narrow.) Again Integrated
Publishing has a good picture of ‘em…
Smart Talk – When you have a boss who doesn't
know diddly-squat trying to talk like he is smart. Although this is usually very
irritating, it can also be quite amusing as well. Apprentices and politicians
are also notorious for this. Soapstone - A soft stone that is pretty
much compressed talc which makes it excellent for marking on STEEL. Solidus
- A SMART TALK way of saying solid. Solid Steel Wire - Mild
steel MIG wire used for
that's right, welding on mild steel. If you're doing
art work, you can use solid steel on stainless also. The welds will rust, but
they will hold as long as there is no stress on them. You would NOT do that on
anything structural as the weld is prone to cracking.
You can also use rolls of FLUX CORE (FCAW), STAINLESS STEEL (SST),
and Aluminum (Al).
Rolls come in a couple of pounds, five, ten, twenty, thirty-three,
and forty-four pounds that I know of.
Off the top of my head I'd say you can get wire rolls at
your local welding supply store, some hardware stores, Loews, Home Depot, Harbor
Freight, Northern Tools, and Grainger.
Spatter - When you weld, especially with the MIG process
and 60 series RODS, the arc force blows small droplets of FILLER
METAL out onto the surface of the PARENT METAL.
In MIG welding you want to either spray the inside of the nozzle
with aerosol, or dip it into a gunky substance that coats the inside
to keep the spatter from sticking. If spatter builds up in the nozzle,
it will obstruct the flow of the Shielding Gas. If using nozzle
dip, you wanta' heat the nozzle by running a few passes first or
you'll just have a nozzle full of gunk.
If the spatter chips off easily, it's no
big deal, if the spatter won't chip off, your temperature is too hot. Also,
if you are working on artwork or something that you really don't want spatter
to get on, you can spray the PARENT METAL or spread the gunk on it and it will
keep the spatter from sticking. One of the stupidest/craziest/nonsensical
things that happened in my teaching career was a student eating a glob of nozzle
dip. It was nasty dirty from months of use, and out of the blue, he ate it. Luckily
it was not toxic and somehow did not make him sick. When I asked him why he did
it, he just looked at me with a weird smile on his face! Spot Weld
- Used on thin gauge metal like car bodies, you have a couple of prongs that grip
the steel kind of like a pair of pliers. In between is a small glob (I like that
word.) of FILLER METAL. The prongs shoot current through the steel melting the
filler metal while firmly holding the steel together. As long as it's set right,
it will melt the filler metal and make a very small, yet strong weld. If it's
set too cold, the weld won't hold. If it's set too hot, it'll just wash the "glob"
of filler metal away, or burn through the steel. It's a good idea to use
it on some scrap pieces of steel to get the AMPS right before doing the real deal.
This
is a small Hobart spot welder. They come in all sizes, some MUCH larger Steel
- Steel is iron ore mined from the ground, purified in blast furnaces, and
then carbon added in its molten stage. If called for, ALLOYS can also be added
while molten. See Steel
Furnance Article. Stick Welding - See SMAW and http://keenovens.com/articles/stick-welding.htm. Done
with either electric powered, or gasoline/diesel operated machine. For heavy fabrication
and construction in structural steel, DIRECT CURRENT is usually used because it
runs smoother than ALTERNATING CURRENT. One exception was when we used AC
machines to run 6011 RODS at a black iron plant I worked at. Stiffening plates
(plate put in the web of a beam to give it extra strength and keep it from sagging)
that we routinely put in could be done with 6011 and it was cheaper using AC current.
On most everything else there we used DC with 7018, or FLUX CORED ARC WELDING. In
the Iron Workers Union, I welded for years pretty much exclusively using 7018
RODS with DC. (7018 are also called Low Hydrogen or LoHi) About the only time
we didn't use 7018 was when we were using 6010 RODS on decking. (We'd burn through
the sheets on the roof into the joists below.) Miller eTraining has a nice
site for basic
electricity
Sticking - A heck of a frustrating occurrence
when the rod sticks to the steel instead of starting an arc. It's usually caused
by the heat not being hot enough, or the wrong ROD angle. The end of the
rod heats up just enough to fuse to the base metal without starting the ARC. This
frustrates the heck out of new welders and that's bad because they then grip the
STINGER even tighter making it likely to again stick the rod. (You gotta' relax
your hand when welding!) If you jerk the stinger quickly enough, you can
free the rod, otherwise you have to disconnect the stinger from the rod, and then
break the rod free. (NOTE: Keep your hood down when disconnecting because it will
make a bright flash.) If FLUX breaks off of the end of the rod, you will
need to "long arc" (hold the rod a quarter inch or so off of the plate
and let it burn) until it burns the exposed FILLER METAL back down to the flux.)
Beginners should practice striking an arc over and over again to learn
how to strike it without sticking. Stick-out - How far the wire
sticks out from the end of the NOZZLE in MIG welding. Stinger -
What we call the ELECTRODE HOLDER in the shop or field. In SMAW there are several
sizes of stingers, from lightweight, to heavy industrial sized. In the field we
would connect the WORK LEAD on a column for completion of the circuit which allowed
us to only drag the stinger lead to where we were welding. (As long as the structure
was steel.) It's a heckuva' lot easier doing that than dragging both leads, especially
working up high walking around on narrow beams! Stringer Bead - The
first bead you should learn after you master starting the arc. Depending on the
rod or process, this bead will be done with a drag action on flat surfaces with
little or no OSCILATION. After the first bead, the others are run parallel to
the first. For flat (see SURFACING) build up welds the beads will overlap
each other. In other words, the bead should wash in to about the halfway point
of the existing bead. That way there is a good TIE-IN making a connection of the
two beads. After several of these are run, the top will be smooth if done correctly.
See also CRATER and OSCILATE. Submerged Arc - When
I was attending a welding school long, long ago, we toured a massive steel plant.
What I saw with them melting down the iron in huge blast furnaces, blowing out
drain holes with dynamite, bright orange molten steel flowing into different forms,
and all the major machinery, was awe inspiring! So I see this guy sitting
by a big machine just kind of watching it with a cig hanging out of his mouth.
I asked what he was doing and he politely said "What the hell does it look
like I'm doing? I'm welding!" "But there's no arc."
I replied. In a mean, sarcastic, cuss-word filled voice, he told me how
they use a bare ELECTRODE set with flux spread out on top of the steel. The flux
cover kept the arc from being seen, so all he did was set the machine, then sit
there and make sure it was working right. It's a very good process for long, continuous
welds. Surfacing - Welds used to build up worn down equipment to
its original form. A good example is a bulldozer. On the back is a sprocket to
make the track go forward or backward. Wheels at the bottom and a few on the top
keep it in line. At the other end from the sprocket is an idler wheel. Its purpose
is to keep the track in place as it continuously rolls. All of these wear
down with use and it is way cheaper to re-surface these welds rather than buy
the new equipment, especially for large shops and jobsites. So a build
up weld is done, usually with a hard surface rod which does just that; it adds
steel and alloys that are very hard so that they don't wear down easy. My
first welding job was doing surface welds on idler wheels. I sat there and slowly
spun the wheel, running the rod back and forth, about 4" left to right. We
started at 8AM. I would weld and figure it must be getting close to lunch and
check my watch
it'd be 8:15AM! It was BORING! But you gotta' start
somewhere, and by sitting there doing a weave pattern over and over, day in day
out, I learned to run a really good continuous bead, so it was a good start. Tack
Weld - Small weld used to hold what you're welding on in place until you weld
it solid. Used extensively in fabricating, tack welds can be easily broken off
if a change needs to be made. It's REAL important that you make sure to
weld ALL points on something that has been tacked, especially if it is going to
be used structurally. One time a fabrication guy welded a "dog"
(temporary lifting eye to hook the shop overhead crane to) on a set of stairs
to lift them a few inches off his table. He forgot to take it off and it shipped
out with the dog still in place. When it got to the field, an unknowing
rookie hooked it on and up it went. On something like that, you tack only on one
side so you can knock it off when you're done. That was plenty for the shop, but
with it swinging in the air the tacks broke loose and the stairs fell about 26
floors to the ground. Miraculously no one was hurt, but the job superintendent
yelled so much it nearly melted the poor shop foreman's phone that day! Make
sure to burn completely into a tack when welding, and don't start or stop a weld
by or on a tack. Tee Joint - When flat, two plates put together
where if you turned them upside down, they'd look like a T. Hmmm
I wonder
if that's how they got their name? Temper - Some steels can be
hardened by heating, then quickly quenching. When our chipping hammers get dull
we sharpen, then temper them.
Using a cutting torch, we heat them to what's called "cherry
red" (orange to me), then stop and let them began to cool until
they're a dull orange. (It's important to keep the tip of the torch
a few inches away to make sure it doesn't melt or scar the steel.)
Then we quickly dip it into a bucket of mineral oil to quickly
cool it. Water will work also, but not as good, and you need to
make sure it is cool or cold.
After that, you've got a re-hardened hammer. After
use, the crystal structure in the steel changes. In hard steel, the crystals are
small and close together. In softer, more ductile steel, the crystals are longer
and further apart from each other.
When the hammers are exposed to heat and constant beating, the crystals
elongate and the ends get dull. We heat them making them flexible and taking the
stress away, then cool them quickly which causes them to contract. Your
pocket knife blade is very hard steel with a high carbon content, which holds
an edge well. If you were to sharpen it on a machine bench grinder and allow it
to heat up, it will no longer keep a good edge because you change it's make up.
Temper is also something that my boss' lost when I was a wiseass to them. Tensile
Strength - Welding RODS such as 7018, 6010, etc. are rated in tensile strength
per square inch. The first two numbers tell the tensile strength in thousands.
(A low-hydrogen 10018 rod would be the first three.) 7018 has 70,000 pounds
of tensile strength per one square inch of weld. 6010 would have 60,000 lbs. That
is a lot of strength for a little amount of weld! Tensile strength is the
ability to resist being pulled apart by TENSION. Strength is measured at the point
it takes to bring the steel or metal to its fatigue point where it fatigues and
tears apart. I do a demonstration where I TACK WELD a 6" X 6"
plate to the end of a table placing only ½" of weld at each end of
the top side with 7018. I then ask students if they would stand on it if
it were 30 stories in the air. Most say they wouldn't so I climb up on the table
and do that stupid crane stance from the Karate Kid standing one legged on the
plate. It shows how much tensile strength two small tacks have, easily
supporting my weight. p.s. Don't tack a plate 30 stories high and do the
crane stance! It's for demo only! And by the way, when we tacked our welding
baskets to stand in working up high, we were always tied off with a safety harness
before we got in them! Tension - Pulling taut or stretching with
force. A good example is a rubberband. Tension is where you stretch it apart.
Also the kind of headache I used to get when I worked up high and looked
down. Test Coupon - I've written about how welders have to prove
themselves more than any other trade or career. This is done either by a destructive
test that destroys the steel, or a non-destructive test such as x-ray. This is
how you become a "certified" welder. On a destructive weld test
in structural welding a GROOVE WELD is made with either an open ROOT, or using
a BACKUP STRIP. Both sides of the plate are ground flush and cut into 1 ½"
strips which are bent in a JIG. The strips are then checked for cracks,
or other defects. If none are found, you get the job, fail and down the road you
go. Usually two strips from the ROOT and two from the FACE will be bent. Sometimes
the strips will actually break in two pieces. If this happens, you might want
to check out another career or get to practicing! Throat of Fillet Weld
- This excellent site from TWI shows various fillet throats. http://www.twi.co.uk/j32k/protected/band_3/jk66.html
Tie-in - After running a STRINGER BEAD a tie-in is made
when another stringer bead parallel to the first, is burned halfway
into it. Instead of them being two beads side by side, they are
intertwined together. Ahhh
they have become one Grasshopper.
Tie-in is very important to give strength when making multiple
pass welds.
TIG Welding (GTAW, Gas Tungsten Arc Welding) - Was called
Heliarc, then Tig, now GTAW. However, most welders out in the field
still call it Tig. If they call it Heliarc, they're old. WAIT a
minute
I've called it Heliarc!!!
This welding process joins metals by heating them with a non-consumable
tungsten electrode. That means the electrode, which is TUNGSTEN,
doesn't melt into the weld the way filler metal in a ROD does.
In STICK WELDING the ROD is being consumed as you weld. As you're
burning into the steel, the rod is melting so you need to be pushing
into the steel as you go to compensate for the end of the rod being
consumed, which makes it shorter.
In Tig you hold the tungsten the same distance from the PARENT METAL
as you weld because it is not being consumed.
It can be done by melting two pieces together with no filler metal,
or with a filler rod that you hold and feed into the weld.
It takes a lot more skill and patience to Tig weld because you
use both hands for different functions and have to feed the rod
correctly. That means a lot of coordination, so if you can't walk
and chew gum at the same time, it's gonna' take a LOT of practice
to get it down.
Basic beads are relatively easy, but out of position, exotic metals,
pipe and tubing, and confined spaces can be very difficult, and
take a long time to master.
That said, if you are going to use it for hobby type, working on
your race car, motorcycle etc. don't let it intimidate you. With
practice you can become proficient.
It uses argon, helium or mixtures of inert gases for shielding
the weld, and with little to no smoke produced; it is very easy
to see the WELD POOL. (Except for Aluminum where the puddle is fairly
hard to see.)
Tig Torch - Made up of a head to protect the tungsten, collet
(sleeve to hold the tungsten) collet body (that's right, it holds
the collet), TUNGSTEN and a ceramic cup. The tungsten carries the
current which produces an arc. Orifices in the collet direct shielding
gas to flow out of the ceramic cup and surround the WELD POOL. Different
people hold the torch different ways. I don't care how you hold
it as long as you're relaxed and the weld comes out ok! Some torches
are air cooled, while others use water or anti-freeze. If you use
a liquid cooled torch, you better be real careful not to set it
down on a hot piece of metal. Spring a leak and you could get shocked
real bad with DC and if you're using AC, you could wake up dead!
The smaller the torch, the faster it gets hot.
Tungsten - This stuff is hard! It also has the highest melting
point of any metal, with only the element carbon having a higher
one. This makes it a good ELECTRODE to use in TIG. It is non-consumable
whereas stick electrodes are consumable. They burn up as you use
them, tungsten doesn't. It carries the arc and makes heat for FUSING
the steel. See TIG.
If you want to pull a good ask for Wolfram. That is the original
name for tungsten because it is mined from ores, one of 'em called
Wolframite. After they ask what the heck you're talking about, explain
and act surprised at their limited metallurgical knowledge.
Undercut - This is the CARDINAL SIN of welding grasshopper!
Cutting into the steel with the force of the arc leaves a cut out
groove in the weld. If this is not filled back in with filler metal,
it leaves a WELD DEFECT which is a weak point that can cause the
joint to fail. This can cause property damage, injury and even loss
of life. See WELD SIGNITURE.
Underfill - is a weld DEFECT that happens when you are not
depositing enough FILLER METAL according to the welding specs.
Underwater Welding - I'm very tempted to put "welding
under water" here. It is either done actually in the water,
or in a hyperbaric chamber which is a submersed room where the water
has been pumped out. If done in the water it is usually for an emergency
repair because there is no way to make a good looking weld underwater,
although you can make one that will hold.
Here's a site with a great paper on the subject
http://www.metalwebnews.com/howto/underwater-welding/underwater-welding.pdf
There are several schools for underwater welding located in different
areas of the nation. Two good ones I know of from visiting or researching
are
The Ocean Corporation
and Santa Barbara
City College. There is also one in Florida and Washington
State that I know of.
Visual Inspection - is the easiest and most fundamental
WELD TEST. After the weld is made, a qualified instructor, inspector,
foreman, superintendent etc. will examine the weld by carefully
looking at it. It will be checked for the "Cardinal Sin"
of UNDERCUT, POROSITY, UNDERFILL, etc.
It only shows the surface, not what is inside. However, you can
pretty much see if someone knows what they are doing by visually
inspecting their welds.
Voltage - is the force that makes the electrons flow through
the conductor. (Make sure you don't become a conductor by always
wearing gloves when you weld, and staying dry!) It's kind of like
when you turn on your garden hose. The water flows because it is
pumped. The pump is like the volts, and the water is like the AMPERAGE.
Warping - is when the steel deforms either by twisting,
bowing, or bending because of heat from the weld. Not usually a
problem with thick steel, but a MAJOR problem with the thin stuff.
There are steps you can take to prevent warping such as putting
the steel in a jig, clamping it down, or immediately cooling it
after it is welded. (Immediately cooling can not be used on some
metals and alloys because it would make them brittle.)
Watch Your Eyes!!! - is what we yell out in our shop to
let people know we are about to strike an arc. You should always
let people know before you strike an arc so they don't get FLASH
BURN.
Weave Bead - is usually used on the last bead, or cap of
the weld. It is made when you OSCILLATE the rod in a wide pattern
back and forth, and in my experience done mostly with 7018 RODS.
Weld - although there are many definitions, the one I like
is the bonding or fusing of two materials. It can be done with or
with out filler rod or wire, and can use all kinds of crazy processes
such as explosive, pressure, laser, and others. My late, non-mechanical
brother used to ask me if I was going to use "jumper cables
and sparklers" when I was STICK WELDING. Many people think
of a welder as some dirty guy standing there with a cig hanging
out his mouth. In some instances, that's the way it is, but there
are MANY welding Processes out there, and new innovations being
discovered all the time. You could be working dirty as heck on some
greasy conveyor belt system, dangerous as heck way up in the air
on a high-rise, or in an absolutely clean, air conditioned and safe
aerospace shop. Welding is a heckuva' diversified trade.
Weldability - is if a metal or steel can be welded, and
with what process?
Weld Blanket - Used to keep sparks, molten steel, and SPATTER
from burning, scarring, or catching surrounding area on fire when
welding or cutting. They're made out of material with a very high
resistance to heat.
Weld Defect - UNDERCUT, POROSITY, SLAG INCLUSION, and UNDERFILL
are all defects which can adversely affect a weld usually causing
a crack which weakens it. Weak welds can damage equipment or materials,
injure or even kill.
Weld Electrode - see RODS.
Weld Face - is on the opposite side of the ROOT OPENING at
the top of the plate. It is where the CAP pass goes.
Weld Gauge - Comes in different sizes and is used by the
WELDING INSPECTOR to check the size of a weld. Measures how much
FILLER METAL is deposited from the ROOT OPENING to the WELD FACE.
Weld Gun - In STICK WELDING we use an ELECTRODE HOLDER which
is called a STINGER in the field. When FLUX CORED, or MIG welding
we use a gun with a trigger on it. When you pull the trigger it
causes the wire to feed and activates the electric ARC.
Weld Joints - Lap, Butt, Edge, Corner and Tee are the five
basic weld joints. Beer and Strip are also a couple of joints many
welders know of.
Weld Metal - is the melting together of the FILLER METAL
(ROD or Wire) and the melted PARENT METAL which forms the welding
bead.
Weld Pass - Made when you deposit the filler metal on the
plate or joint while traveling the length of the PARENT METAL. In
some cases one pass is enough while others require multiple passes.
Just depends on what you're working on.
Weld Pool - see WELD PUDDLE.
Weld Positions - in structural steel there's Flat, Horizontal,
Vertical and Overhead.
Fillet welds are done on a Tee Joint:
1F = Flat Fillet, 2F = Horizontal Fillet, 3F = Vertical Fillet,
and 4F Overhead Fillet
Groove welds are done on plate:
1G = Flat Groove, 2G = Horizontal Groove, 3G = Vertical Groove,
and 4G = Overhead Groove.
Weld Symbol – is the design on a WELDING SYMBOL that tells what kind of weld you are to make. i.e. Fillet, Lap, Butt etc.
http://files.aws.org/technical/errata/A2.4errata.pdf
Welding Certification – papers showing what test/procedures a welder has passed. Many people put too much emphasis on being “certified.” You might be able to pass a test 100% in a controlled environment. That is a whole different ball game than making it 30 floors up in the air, with the cold wind blowing down your neck while standing on a 2” wide beam!
There are many different certifications and several different institutions that offer them such as…
- American Welding Society – structural steel.
- American Society of Mechanical Engineers – boilers and pressure vessels.
- American Petroleum Institute – oil and gas pipelines
Welding Procedure – How they want it done. Listed on blueprints or notes to the welder as a WPS or Welding Procedure Specification, it tells you how to prepare the joint, what process to weld it with, size and dimensions of the weld itself, how many passes, and what kind of finish it will have. i.e. chip and brush, machine grind or buff.
Welding Symbol – (see also Weld Symbol) - Shows what type of weld, where it's gonna' be, the size and dimensions.
It has an arrow that points to where on the joint the weld will be, a reference line where the WELD SYMBOL is, and a “tail” for information on the weld itself.
Welding Technique – is how you make the weld. There are different techniques for different welds. For STICK WELDING using 6010 you OSCILLATE the ROD in either circles, or a “whip and pause” where you are whipping the rod in and out of the WELD POOL. This is a radical technique compared to 7014 which you drag steadily with little ossicalation.
Some instructors will insist you use ONLY their technique. I don't care if you stand on your head gargling peanut butter as long as you get the weld right. If your technique makes for a sound weld, then it is fine by me.
Wire Brush – A real important tool for both pre and post-cleaning a weld. In welding “Cleanliness is Godliness” ESPECIALLY in Mig welding. Mig doesn't work worth a dang if there is paint, rust, or dirt on the metal. Although STICK and FLUXCORE can burn through some paint, rust and dirt, it is still preferable to have a clean surface if at all possible. The cleaner the surface, the better your chance of a good, pure, sound weld.
There are hand brushes, brushes that fit on hand grinders, and brushes that fit on bench grinders.
After running a pass it is important to brush it good, especially if you are going to run another pass over it.
If you are showing your weld to your instructor, or turning it in for a certification test, it is in your best interest to clean the weld properly. The better you clean it, the better it'll look!
Weld Procedure – The AWS sez a weld procedure is "the detailed methods and practices including all joint welding procedures involved in the production of a weldment." When I first started welding and I read definitions like that I was like “What the? Who the? Where the? Are you freaking kidding me?” So here's my translation…”how you're gonna' do the weld.”
Blueprints have weld procedures which tell what kind of process, and what number, thickness, width and length of the weld is required.
On a big job, the superintendent will go over the weld procedures with the general foreman, who will go over it with the foreman, who will go over it with the welder.
In a shop the foreman will go over it with the welders.
Weld Puddle - or WELD POOL, is the molten metal produced while the weld is being made. It can be made from melting the PARENT METAL alone, the PARENT METAL combined with FILLER METAL, or mostly FILLER METAL in SURFACING.
It needs to be protected from atmospheric contaminants by a gas shield produced either from the flux of an ELECTRODE, or SHEILDING GAS.
Weld Size – Yes grasshopper, in welding size DOES matter. The size of the weld is located on the WELDING SYMBOL and should not be any more or less than what it calls for.
Weld Symbol – is on the WELDING SYMBOL and tells what kind of weld is going to be made. A good site I found illustrating this and welding symbols is http://www.tpub.com/steelworker1/29.htm
Weld Test – There are Visual tests, Destructive tests, and Non-Destructive tests in welding. In welding you have to prove yourself more often and in harder ways than any other trade.
Visual Test - See VISUAL INSPECTION.
Destructive Test – In structural welding two plates welded together are then cut into coupon strips usually 1 ½” wide. The FACE and ROOT OPENING sides of the plate are grinded flush.
They are bent in a jig, two face sides, and two root sides, and if they bend with no cracks or POROSITY, or SLAG INCLUSION, you get the job.
Photo from http://www.wtti.edu/coupons.html
If they have cracks, porosity, or slag inclusion…head on down the road.
Non-Destructive Test – is used when it is impractical to do a destructive test, or to get a complete view of the weld. There are several types such as X-ray, Magnetic Particle, Ultrasound, and Liquid Penetrate Dye tests.
X-ray shows pretty much EVERY part of the weld. If there is ANYTHING at all wrong, it is gonna' show up! Welds done to X-ray codes have zero tolerance. That means you better weld it perfect EVERY weld, EVERY time!
In my years as a structural welder in the Iron Workers union I tested on jobsites with Destructive Bend tests, or X-ray. There are many other tests done, but here I'm only describing these two. You can find more on the other testing methods in most any welding journal, or search ‘em on the net.
This
list of Welding Terms is brought to you by Keen Ovens, leader in Welding Storage
Ovens.
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