120103a-bA Wire Feed Welding Equipment and Consumable Part A Flashcards
Wire Feed Welding Equipment and Consumables : Part A
To protect yourself from electrical shock when welding, what must you ensure?
Answer: Ensure that all electrical equipment is properly grounded.
Explanation: Proper grounding of electrical equipment is crucial to prevent electrical shocks, which can be dangerous or even fatal. Grounding provides a safe path for electricity to be discharged, reducing the risk of electric shock.
What are the first two signs of oxygen deficiency?
Answer: Dizziness and euphoria.
Explanation: Oxygen deficiency in the welding environment can lead to dizziness and euphoria as early symptoms. This condition arises when shielding gases used in welding displace the oxygen in the air, creating a hazardous environment that can affect brain function and consciousness.
What shade of filter plate do AWS and CSA recommend as the minimum?
Answer: #10.
Explanation: The American Welding Society (AWS) and the Canadian Standards Group (CSA) recommend a minimum filter plate shade of #10 for welders’ helmets. This shade helps protect the eyes from intense light and radiation produced during welding, which can cause eye damage.
What is the primary function of shielding gas?
Answer: To shield the molten weld metal from atmospheric contamination.
Explanation: Shielding gases are used in welding to protect the molten weld pool from atmospheric gases, such as oxygen and nitrogen, that can cause defects like porosity and weak welds. These gases create a protective envelope around the weld area.
List the two outputs produced by common welding sources.
Answer: Constant current (CC) and constant voltage (CV).
Explanation: Welding power sources typically provide either constant current (CC) or constant voltage (CV). CC is used where the current remains steady despite changes in voltage, suitable for processes like SMAW and GTAW. CV is used in processes like GMAW, where voltage is kept constant to maintain a stable arc, despite fluctuations in current.
What do flowmeters control?
Answer: Flowmeters control the rate of flow of shielding gas to the gun nozzle.
Explanation: Flowmeters are essential for regulating the amount of shielding gas delivered to the welding area. Proper flow rate ensures adequate protection of the molten weld pool from atmospheric contamination while avoiding excessive gas usage.
What should your protective clothing characteristics be when welding with GMAW, and why?
Answer: Clothing should be dark, tightly knit 100% cotton to reduce reflected light radiation and promote fire-resistance.
Explanation: Dark, tightly knit cotton clothing minimizes the risk of burns from sparks and reduces light reflection, which can cause glare and impair vision. Cotton is preferred for its fire-resistant properties compared to synthetic materials.
What precautions should you take when welding under wet weather conditions or standing on wet surfaces?
Answer: Protect yourself from electrical shock hazards by wearing rubber boots with dry socks and gloves.
Explanation: Wet conditions greatly increase the risk of electrical shock. Rubber boots and gloves provide insulation, reducing the risk of electricity passing through the body, which can be fatal.
Name the two toxic gases that the ultraviolet light from welding will produce.
Answer: Ozone and Phosgene gas (from chlorinated hydrocarbon degreasers).
Explanation: Ultraviolet light from welding can react with oxygen to form ozone and with chlorinated solvents to form phosgene gas, both of which are highly toxic and dangerous to health.
How might using a shielding gas during welding affect air quality?
Answer: Shielding gases in sufficient quantities displace enough air to render the work area oxygen deficient. Dizziness or euphoria is usually the first sign of oxygen deficiency.
Explanation: High concentrations of shielding gases can displace oxygen in the air, leading to an oxygen-deficient environment. This can cause symptoms like dizziness or euphoria, indicating a need for proper ventilation and air monitoring.
List the essential equipment components always required to set up a wire feed outfit.
Answer: Power source, wire feeder, gun and cable assembly, spooled filler wire, shielding gas, and gas control equipment.
Explanation: These components are fundamental for wire feed welding setups. The power source generates the welding current, the wire feeder controls the filler wire feed, the gun and cable assembly deliver the current and wire to the weld, and the shielding gas and control equipment regulate gas flow to protect the weld pool.
What three properties are wire feed welding power source ratings based on?
Answer: Amperage, Voltage, Duty cycle.
Explanation: Power source ratings are based on these properties to determine their suitability for various welding applications. Amperage and voltage define the power source’s capacity, while the duty cycle indicates how long it can operate continuously at a given amperage and voltage without overheating.
What is the most common current that the wire processes use?
a) Constant current (CC)
b) Constant voltage (constant potential)
c) Alternating current (AC)
d) High frequency (hf)
Answer: b) Constant voltage (constant potential).
Explanation: Constant voltage systems are commonly used in wire welding processes as they maintain a relatively stable voltage level, which is crucial for a consistent arc and weld quality.
A CV power source increases or decreases the welding current to account for what?
Answer: Voltage fluctuations.
Explanation: A Constant Voltage (CV) power source adjusts the welding current to compensate for voltage fluctuations. This ensures a stable arc and consistent welding quality, even if the voltage changes.
What is preset by the voltage control on the power source?
Answer: Desired arc length.
Explanation: The voltage control on a power source is used to preset the desired arc length. Voltage directly influences arc length, with higher voltages producing longer arcs and vice versa.
