Embedded Files
Link to = Google Classroom
Welding Classroom Code: See Instructor
Welding 1 3rd Period Technology
Welding is nothing more than the art of joining metals together. By comparison, wood is joined by nails, bricks are held together with mortar; metal is joined by welding! What makes welding such a big deal is that the world’s infrastructure depends on it! Everything you touch everyday that is made of metal is most likely welded in one form or another. It is one of the most valuable technologies that played a huge part in the industrial revolution, and is the back bone to the world’s militaries. Welding today is comprised of three main ingredients which are required to join metals together.
An electrical power source to produce an arc.
Some form of shielding to protect the weld from the air.
Filler material to fill the weld joint.
The ways these three ingredients work together are:
First, the weld area needs to be shielded from any air around it. This is important because oxygen and other gasses in the air make welds brittle and porous.
Second, is the electricity to produce an arc. An electrical arc melts metal in fractions of a second and is hot enough to melt any known metal!
Finally, the filler metal is added, which is how two pieces of metal become one.
Stick Welding is a slang term commonly used for Shielded Metal Arc Welding or “SMAW”. Stick welding is the most basic and common type of welding processes used. It is also the first process learned in any welding school. Stick is the most trouble free of all of the welding processes and is the fundamental basis for all the skills needed to learn how to weld!
Stick welders have four main components.
A ground lead or clamp.
A welding lead or stinger.
A constant amperage power source.
The electrode or welding rod to weld with.
The process is simple! The ground clamp is attached to the work or metal to be welded. Then the welding lead, or stinger, gets the electrode inserted in it. Finally, the power supply is turned on and only requires the user to strike the metal to ignite it. Once that is done. the arc starts and the electrode begins to burn. This creates a shielding gas and deposits metal into the joint that is being welded. The slag from the electrode needs to be cleaned or chipped off as soon as the weld is finished.
MIG Welding is a slang term that stands for Metal Inert Gas Welding, the proper name is Gas Metal Arc Welding or “GMAW”, and it is also commonly referred to as “Wire Wheel Welding” by Unions. MIG Welding is commonly used in shops and factories. It is a high production welding process that is mostly used indoors.
MIG Welders have five main components.
A constant voltage power supply.
A wire feed to feed the filler wire through the welding lead to the MIG gun.
A ground lead or clamp.
A welding lead or MIG gun.
Shielding gas to protect the weld area from the air.
MIG welding is not that simple when it comes to setting up the equipment but the skill required is a lot less then Stick welding. The way MIG welding works is you attach the ground clamp to the work then power source is turned on and finally the shielding gas needs to be turned on. After that you need to set the voltage, wire feed speed that is counted in IPM (inches per minute), and shielding gas flow rate that is counted in CFH @ 20 (cubic feet per hour). Then simply hit the trigger and the MIG gun starts feeding shielding gas and wire to the weld joint. Once the wire hits the weld joint it begins to arc and the wire melts and starts filling the joint.
Flux Cored Arc Welding “FCAW” is nothing more than a different welding wire or electrode for a MIG welder! FCAW wire is a hollow or tubular wire that has a flux inside of it that provides a shielding from the air when it is welding. What this does is help a MIG welder to weld in windy conditions and it increases how much weld can be welded per hour. The powder flux inside also has metal mixed in that increase the weld deposit rate.
FCAW is the fastest of all of the manual welding processes. FCAW wire has two types.
Self Shielding.
Dual Shielding.
Shelf shielding wire is just that! It has enough flux inside that no other shielding source is needed.
Dual Shield is a wire that helps shield the weld but also needs a source of gas just like a MIG welder.
Flux cored arc welding is similar to Stick welding when it comes to slag. It also has a slag that covers the weld that needs to be cleaned after the weld is finished.
Oxy-Acetylene, commonly known as Oxy-fuel, is one of the oldest welding processes, though in recent years, it has become less popular in industrial applications. However, it is still widely used for a variety of applications. Oxy-fuel equipment is versatile, lending itself to welding, brazing, braze-welding, silver soldering, metal heating (for bending and forming) and oxy-fuel cutting. Our book will highlight the welding and cutting processes.
A well balanced neutral flame is used for welding most steels. To be sure the flame is not oxidizing, it is sometimes used with a slight acetylene feather. A very slight excess of acetylene may be used for welding alloys with a high carbon, chromium, or nickel content. However, increased welding speeds are possible by using a slightly reduced flame. Avoid excessive gas pressure because it gives a harsh flame. This often results in cold shuts or laps, and makes molten metal control difficult.
The tip size and volume of flame used should be sufficient to reduce the metal to a fully molten state and to produce complete joint penetration. Care should be taken to avoid the formation of molten metal drip heads from the bottom of the joint. The flame should bring joint edges to the fusion point ahead of the puddle as the weld progresses.The pool of the molten metal should progress evenly down the seam as the weld is being made.The inner cone tip of the flame should not be permitted to come in contact with the welding rod, molten puddle, or base metal. The flame should be manipulated so that the molten metal is protected from the atmosphere by the envelope or outer flame.
The end of the welding rod should be melted by placing it in the puddle under the protection of the enveloping flame. The rod should not be melted above the puddle and allowed to drip into it.
http://www.artic.edu/webspaces/portal/irfm/IntroOxyAcetylene.pdf
Information is from the above PDF and is an excellent resource for you the student.
Welding Torch Flame Types
Welding Torch Flame Types
Shown: Carburizing flame (left), Neutral flame (center), Oxidizing flame (right)
Neutral Welding Flame
Neutral Welding Flame
Temperature Gradient of a Neutral Welding Flame
The neutral flame has a one-to-one ratio of acetylene and oxygen. It obtains additional oxygen from the air and provides complete combustion. It is generally preferred for welding. The neutral flame has a clear, well-defined, or luminous cone indicating that combustion is complete.
Neutural welding flames are commonly used to weld:
Components of this site came from the "web" and are acknowledged as such.
Tip: How to post an announcement, student of the month, word of the week, or new assignments
Page updated
Google Sites
Report abuse