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16 Cards in this Set
- Front
- Back
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When oxygen and nitrogen from the atmosphere become mixed in the molten weld metal, they: |
Answer: form harmful oxides and nitrides in the weld metal |
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Which gas is the lightest? |
Answer: hydrogen |
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Argon and helium are: |
Answer: inert gases |
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A characteristic of carbon dioxide shielding gas used with short-circuiting metal transfer is: |
Answer: high weld metal loss in the form of spatter |
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Which modes of metal transfer are possible with GMAW using 0.9 mm (0.035") mild steel wire and carbon dioxide shielding gas? |
Answer: globular and short circuiting` |
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The addition of oxygen to argon causes the temperature of the molten metal to: |
Answer: increase |
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Compared to C02 , argon is an excellent shielding gas for GMAW because it promotes the use of: |
Answer: spray metal transfer |
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When 1% - 9% oxygen is added to argon shielding gas, it is to: |
Answer: improve wetting action |
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Which of the following gas mixes tends to produce low-corned weld beads on stainless steels? |
Answer: argon-helium-carbon dioxide |
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What is an advantage of using 75% argon + 25% CO2 gas mix on carbon steel? |
Answer: improved arc characteristics |
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Which gas is generally used for shielding when using MCAW? |
Answer: a mixture of argon and carbon dioxide |
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The purpose of a flowmeter is to: |
Answer: maintain a constant flow rate of gas |
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The preferred method of measuring shielding gas supply is: |
Answer: litres per minute (cubic feet per hour) |
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Flowmeters are calibrated to indicate the: |
Answer: volume of shielding gas supplied |
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What can be done to avoid regulator freeze-up when using CO2 gas? |
Answer: install a line heater or manifold system |
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What must be considered before using a mini-bulk system? |
Answer: frequency of use |
