Structures Wldng

In Gas Tungsten Arc (GTA) welding, a stream of inert gas is used to. A - concentrate the heat of the arc and prevent its dissipation. B - prevent the formation of oxides in the puddle. C - lower the temperature required to properly fuse the metal.

Which statement best describes magnesium welding?. A - Filler rod should be nickel steel. B - Magnesium can be welded to other metals. C - Filler rod should be the same composition as base metal.

Which statement is true in regard to welding heat-treated magnesium?. A - Magnesium cannot be repaired by fusion welding because of the high probability of igniting the metal. B - Flux should not be used because it is very difficult to remove and is likely to cause corrosion. C - The welded section does not have the strength of the original metal.

The oxyacetylene flame for silver soldering should be. A - carburizing. B - oxidizing. C - neutral.

Why is it necessary to use flux in all silver soldering operations?. A - To chemically clean the base metal of oxide film. B - To prevent overheating of the base metal. C - To increase heat conductivity.

Engine mount members should preferably be repaired by using a. A - smaller diameter tube with fishmouth and rosette welds. B - larger diameter tube with fishmouth and no rosette welds. C - larger diameter tube with fishmouth and rosette welds.

What method of repair is recommended for a steel tube longeron dented at a cluster?. A - Welded patch plate. B - Welded split sleeve. C - Welded outer sleeve.

Welding over brazed or soldered joints is. A - not permitted. B - permissible for mild steel. C - permissible for most metals or alloys that are not heat treated.

Which statement concerning soldering is correct?. A -Joints in electric wire to be soldered should be mechanically secure prior to soldering. B - Changeable shades of blue can be observed on the surface of a copper soldering tip when the proper temperature for soldering has been reached. C - If the soldering temperature is too high, the solder will form in lumps and not produce a positive bond.

A resurfaced soldering iron cannot be used effectively until after the working face has been. A - tinned. B - fluxed. C - polished.

Which of the following can normally be welded without adversely affecting strength? 1. Aircraft bolts. 2. SAE 4130 chrome/molybdenum tubing. 3. Spring steel struts. 4. Most heat-treated steelhickel alloy components. A - 2. B - 2 and 4. C - 1 and 3.

In selecting a torch tip size to use in welding, the size of the tip opening determines the. A - melting point of the filler metal. B - temperature of the flame. C - amount of heat applied to the work.

Why should a carburizing flame be avoided when welding steel?. A - It hardens the surface. B - It removes the carbon content. C - A cold weld will result.

The most important consideration(s) when selecting welding rod islare. A - current setting or flame temperature. B - material compatibility. C - ambient conditions.

The oxyacetylene flame used for aluminum welding should. A -be neutral and soft. B - contain an excess of acetylene and leave the tip at a relatively low speed. C - be slightly oxidizing.

A very thin and pointed tip on a soldering copper is undesirable because it will. A - transfer too much heat to the work. B - have a tendency to overheat and become brittle. C - cool too rapidly.

Filing or grinding a weld bead. A - may be performed to achieve a smoother surface. B - reduces the strength of the joint. C - may be necessary to avoid adding excess weight or to achieve uniform material thickness.

Acetylene at a line pressure above 15 PSI. A - is dangerously unstable. B - should be used when a reducing flame is necessary. C - is usually necessary when welding metal over 318- inch thick.

Cylinders used to transport and store acetylene. A - are green in color. B - contain acetone. C - are pressure tested to 3,000 PSI.

A welding torch backfire may be caused by. A - using too much acetylene. B - a loose tip. C - a tip temperature that is too cool.

Which statement concerning a welding process is true?. A - The inert arc welding process uses an inert gas to protect the weld zone from the atmosphere. B - In the oxyacetylene welding process, the filler rod used for steel is covered with a thin coating of flux. C - In the metallic arc welding process, filler material, if needed, is provided by a separate metal rod of the proper material held in the arc.

Where should the flux be applied when oxyacetylene welding aluminum?. A - Applied only to the welding rod. B - Painted on the surface to be welded and applied to the welding rod. C - Painted only on the surface to be welded.

What purpose does flux serve in welding aluminum?. A - Removes dirt, grease, and oil. B - Minimizes or prevents oxidation. C - Ensures proper distribution of the filler rod.

Why are aluminum plates 11, inch or more thick usually preheated before welding?. A - Reduces internal stresses and assures more complete penetration. B - Reduces welding time. C - Prevents corrosion and ensures proper distribution of flux.

How should a welding torch flame be adjusted to weld stainless steel?. A - Neutral. B - Slightly oxidizing. C - Slightly carburizing.

Oxides form very rapidly when alloys or metals are hot. It is important, therefore, when welding aluminum to use a. A - filler. B - solvent. C - flux.

In gas welding, the amount of heat applied to the material being welded is controlled by the. A - distance the tip is held from the work. B - amount of gas pressure used. C - size of the tip opening.

Oxygen and acetylene cylinders are made of. A - bronze. B - seamless aluminum. C - steel.

When inspecting a butt welded joint by visual means,. A - look for evidence of excessive heat in the form of a very high bead. B - the penetration should be 100 percent of the thickness of the base metal. C - the penetration should be 25 to 50 percent of the thickness of the base metal.

Annealing of aluminum. A - increases the tensile strength. B - makes the material brittle. C - removes stresses caused by forming.

Edge notching is generally recommended in butt welding above a certain thickness of aluminum because it. A - aids in getting full penetration of the metal and prevents local distortion. B - helps hold the metal in alignment during welding. C - aids in the removal or penetration of oxides on the metal surface.

If too much acetylene is used in the welding of stainless steel,. A - oxide will be formed on the base metal close to the weld. B - a porous weld will result. C - the metal will absorb carbon and lose its resistance to corrosion.

The shielding gases generally used in the Gas Tungsten Arc (GTA) welding of aluminum consist of. A - a mixture of nitrogen and carbon dioxide. B - helium or argon, or a mixture of helium and argon. C - nitrogen or hydrogen, or a mixture of nitrogen and hydrogen.