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31 Cards in this Set
- Front
- Back
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Name the 3 principle types of welding.
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1. GAS welding
2. Electric Arc welding 3. Electric Resistance welding |
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What are some advantages of gas shielded arc welding?
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1. The weld is stronger
2. more ductile 3. more corrosion resistant. |
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Which method of welding is less likely to cause buckling or warping of thin metal sheets?
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Electric arc ( TIG ) welding
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What is the purpose of shielding an arc weld with inert gas?
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The gas prevents atmospheric oxygen and/or nitrogen from contaminating the weld.
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What is a common method of controlling expansion when welding a joint?
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Place tack welds along the length of the joint.
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What is the effect of inadequate penetration on a weld?
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The weld will be weak.
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What is the purpose of the flux used with brazing and silver soldering ?
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The flux cleans the base metal by removing any oxide film
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What type of flame is used when torch brazing or silver soldering?
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A neutral flame.
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What must be done to a SOLDERING IRON tip to increase the amount of heat transferred from the tip to the work?
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The tip must be clean of all contaminates and properly tinned.
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What is the preferred method for welding aluminum?
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Tungsten Inert Gas (TIG) welding
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what is the preferred method of welding magnesium?
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Tungsten Inert Gas (TIG) welding
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What precautions must be observed in order to weld titanium?
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All traces of oxygen and nitrogen must be kept away from the weld area
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Describe one type of repair that could be made to a dented steel tube cluster joint.
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A formed steel patch plate could be welded over the damaged area.
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How can a soft flame be obtained without reducing the heat output of the torch.
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Use a larger tip and adjust the gas pressure accordingly.
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What factors determine the amount of heat delivered by a gas welding torch?
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1. size of the torch tip
and 2. the gas pressure |
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when a gas welding project is complete
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what safety precautions should be accomplished?
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What should be done to a heat treated aluminum part after welded repairs are completed?
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the part must be RE-heat treated
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welding magnesium can create a serious safety hazard. what is the nature of this hazard?
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magnesium burns with a very hot flame that is very hard to extinguish
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what technique might be used to enable a tight-fitting inner sleeve to be inserted into a tubular repair?
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the inner tube could be chilled with dry ice or in a freezer while the outer tube could be heated slightly with a torch.
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What type of weld joint must be used to weld magnesium
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Only butt welds are used to Weld magnesium. This is to prevent the possibility of trapping the flux
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Why must all flux be removed from the metal after welding magnesium
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Any flux left on the metal will result in severe corrosion
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What must be done in order to successfully weld titanium
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The weld zone must be shielded with an inert gas such as helium or argon
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What is an advantage of electric arc welding over gas welding
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1. less buckling
2. less warping of the welded material |
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What will be the result of using a torch tip that is too large or too small
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Too large the heat will be too great and holes may be burned in the metal. Too small the heat provided may be insufficient to produce penetration to the proper depth causing a low strength weld
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How do you determine the correct size filler rod to be used in welding
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The diameter of the rod to be used is governed by the thickness of the metals being joined.
If the rod is too small it will not conduct heat away from the puddle rapidly enough and a burned Weld will result. A filler rod that is too large will chill the puddle. |
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What is brazing
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A metal joining process in which the bonding material is a nonferrous metal with a melting point lower than that of the metals being welded.
it includes silver soldering copper brazing and aluminum brazing. It Can be used to join metals that are damaged by high heat |
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Why is it especially desirable to use a soft flame when welding aluminum
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Avoid blowing holes in the metal when the puddle is formed
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What is the purpose of using flux when welding aluminum
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Aluminum and it's alloys combined with air and form oxides very rapidly and oxides form doubly fast if the metal is hot.
Aluminum welding flux is designed to remove the aluminum oxide by chemically combining with it. Aluminum fluxes dissolve below the surface of the puddle and float the oxides to the surface where they can be removed. |
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What is the maximum safe pressure for acetylene gas when welding
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When acetylene gas is compressed in a container to a pressure of greater than 15 psi it becomes dangerously unstable.
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What are the procedures for preparing a metal fuel tank for welding
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1. The interior of the tank should be washed thoroughly with hot water and a detergent
2. then steamed for a minimum of 30 minutes. 3. Then fill the tank with CO2 gas from a fire extinguisher and seal the tank except for of small vent hole. |
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What is the difference between brazing and welding
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In brazing the base metal is not melted but is covered with a low melting point alloy
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