1.
Which type of submerged arc welding flux is susceptible to moisture pick-up?
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A.
Neutral
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B.
Agglomerated
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C.
Fused
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D.
Are all about the same
Correct Answer
B. AgglomeratedExplanation
Agglomerated submerged arc welding flux is susceptible to moisture pick-up. This is because agglomerated flux consists of small particles that are bonded together, leaving spaces between them where moisture can be trapped. Moisture in the flux can lead to porosity and other defects in the weld, affecting its quality and strength. Therefore, proper storage and handling of agglomerated flux is necessary to prevent moisture absorption and ensure optimal welding results.Rate this question:
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2.
A Large grain size in the HAZ of a C-Mn Steel weld joint may have:
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A.
Low ductility
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B.
Low toughness
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C.
High toughness
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D.
High tensile strength
Correct Answer
B. Low toughnessExplanation
A large grain size in the Heat Affected Zone (HAZ) of a C-Mn Steel weld joint may result in low toughness. This is because larger grain sizes can lead to reduced resistance to crack propagation and increased brittleness, resulting in lower toughness. This means that the material is more prone to fracture and less able to absorb energy before breaking. Therefore, a weld joint with a large grain size in the HAZ may have lower toughness compared to one with a smaller grain size.Rate this question:
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3.
A STRA test is used to measure the:
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A.
Tensile strength of the welded joint
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B.
Level of residual stress in butt joints
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C.
Fracture toughness of the HAZ
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D.
Through-thickness ductility of a steel plate (the Z direction)
Correct Answer
D. Through-thickness ductility of a steel plate (the Z direction)Explanation
The STR test is specifically used to measure the through-thickness ductility of a steel plate in the Z direction. This test helps determine the ability of the steel plate to withstand deformation or stretching perpendicular to its surface. It provides valuable information about the material's strength and its ability to resist cracking or breaking when subjected to forces applied in the Z direction. Therefore, the correct answer is through-thickness ductility of a steel plate (the Z direction).Rate this question:
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4.
The risk of hydrogen cracking is greater when MMA welding:
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A.
C-Mn Steels
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B.
Austenitic Stainless Steels
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C.
Low Alloy Steels For Elevated Temperature Service
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D.
Low Carbon Steels For Cryogenical Service
Correct Answer
C. Low Alloy Steels For Elevated Temperature ServiceExplanation
The risk of hydrogen cracking is greater when MMA welding low alloy steels for elevated temperature service. This is because low alloy steels contain higher levels of hydrogen, which can become trapped in the weld metal during the welding process. When the temperature of the weld cools down, the hydrogen can cause cracking in the weld. This risk is particularly high in elevated temperature service, as the higher temperatures can increase the mobility of hydrogen atoms, making them more likely to migrate and cause cracking.Rate this question:
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5.
The property of a material which has the greatest influence on welding distortion is its
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A.
Yield strength
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B.
Coefficient of thermal expansion
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C.
Elastic modulus
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D.
Coefficient of thermal conductivity
Correct Answer
B. Coefficient of thermal expansionExplanation
The coefficient of thermal expansion refers to how much a material expands or contracts when subjected to changes in temperature. When welding, the heat from the welding process causes the metal to expand, and as it cools down, it contracts. The coefficient of thermal expansion determines the magnitude of this expansion and contraction, which can lead to significant distortion in the welded structure. Therefore, the coefficient of thermal expansion has the greatest influence on welding distortion.Rate this question:
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6.
Which of the following is a suitable shielding gas for FCAW of stainless steels?
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A.
100% Argon
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B.
70% Argon + 30% He
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C.
Argon + 5% Hydrogen
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D.
Argon + 20% CO2
Correct Answer
D. Argon + 20% CO2Explanation
Argon + 20% CO2 is a suitable shielding gas for FCAW of stainless steels because it provides good arc stability, excellent weld bead appearance, and helps prevent oxidation and contamination during the welding process. The addition of 20% CO2 helps to improve the penetration and weld pool fluidity, resulting in a stronger and more reliable weld.Rate this question:
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7.
The presence of iron sulphides in a weld bead may cause:
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A.
Solidification cracking
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B.
Hydrogen cracking
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C.
Lamellar tearing
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D.
Weld decay
Correct Answer
A. Solidification crackingExplanation
The presence of iron sulphides in a weld bead can cause solidification cracking. Solidification cracking, also known as hot cracking or hot tearing, occurs during the solidification process of the weld when the material contracts and experiences high stresses. Iron sulphides have a low melting point and can form liquid films or pockets during solidification. These liquid films act as crack initiation sites, leading to the formation of solidification cracks. Therefore, the presence of iron sulphides increases the likelihood of solidification cracking in a weld bead.Rate this question:
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8.
A macrosection is particularly good for showing:
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A.
The weld metal HAZ microstructure
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B.
Overlap
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C.
Joint hardness
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D.
Spatter
Correct Answer
B. OverlapExplanation
A macrosection is particularly good for showing overlap in a welding joint. A macrosection is a cross-sectional view of a weld that allows for a detailed examination of the weld's structure and integrity. Overlap refers to the condition where the edges of the base metals being welded do not properly fuse together, resulting in a weak joint. By examining a macrosection, one can easily identify if there is any overlap present in the weld, which is crucial in assessing the quality and strength of the joint.Rate this question:
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9.
Which of the following procedures would be expected to produce the least distortion in a 15mm straight butt weld?
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A.
TIG weld, single-sided, multi-pass
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B.
MMA weld, single-sided, multi-pass
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C.
MMA weld, double-sided, multi-pass
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D.
SAW weld, 1 pass per side
Correct Answer
D. SAW weld, 1 pass per sideExplanation
The Submerged Arc Welding (SAW) process is known for its ability to produce high-quality welds with minimal distortion. By using a single pass per side, the heat input is controlled and evenly distributed, resulting in less distortion compared to other methods. TIG and MMA welds, whether single-sided or double-sided, require more passes and higher heat input, increasing the chances of distortion. Therefore, the SAW weld with one pass per side would be expected to produce the least distortion in a 15mm straight butt weld.Rate this question:
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10.
A suitable gas/gas mixture, for GMAW for aluminium is:
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A.
100% CO2
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B.
100% Argon
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C.
80% Argon + 20% CO2
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D.
98% Argon + 2% 02
Correct Answer
B. 100% ArgonExplanation
The suitable gas/gas mixture for GMAW (Gas Metal Arc Welding) for aluminum is 100% Argon. Argon is commonly used as a shielding gas for aluminum welding because it provides excellent protection against atmospheric contamination and produces a stable arc. It helps prevent oxidation and ensures a clean weld with minimal porosity. Argon also has good heat transfer properties, which is important for maintaining proper weld penetration and preventing distortion. Therefore, using 100% Argon as the shielding gas is the most appropriate choice for GMAW on aluminum.Rate this question:
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11.
Which of the following is associated with SAW more often than it is with MMA welds?
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A.
Hydrogen cracking in the HAZ
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B.
Solidification cracking in the weld metal
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C.
Reheat cracking during PWHT
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D.
Lamellar tearing
Correct Answer
B. Solidification cracking in the weld metalExplanation
Solidification cracking in the weld metal is associated with SAW (Submerged Arc Welding) more often than it is with MMA (Manual Metal Arc) welds. Solidification cracking occurs when the weld metal cools and solidifies, and it is more likely to happen in SAW due to its high heat input and slower cooling rate. MMA welds, on the other hand, have a faster cooling rate, reducing the likelihood of solidification cracking.Rate this question:
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12.
EN ISO 5817 (Level C) specifies that the limit for the diameter (D) of a single pore in a weld is:D<0.3s, but max. 4mm where s=material thickness.For which of the following situations is the pore acceptable?
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A.
S=20mm, measured pore diameter = 5mm
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B.
S=15mm, measured pore diameter = 4.5mm
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C.
S=10mm, measured pore diameter = 3mm
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D.
S=10mm, measured pore diameter = 3.5mm
Correct Answer
C. S=10mm, measured pore diameter = 3mmExplanation
According to EN ISO 5817 (Level C), the limit for the diameter of a single pore in a weld is DRate this question:
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13.
To measure arc voltage accurately it is recommended that the voltmeter should be connected:
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A.
Across the arc and as near as practical to the arc
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B.
Across the power source terminals prior to arc initiation
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C.
Across the power source terminals during the welding operation
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D.
Anywhere in the circuit
Correct Answer
A. Across the arc and as near as practical to the arcExplanation
To measure arc voltage accurately, it is recommended to connect the voltmeter across the arc and as near as practical to the arc. This is because the arc voltage is the voltage drop across the arc itself, and measuring it as close as possible to the arc ensures that any voltage drop in the circuitry or cables is minimized. By measuring the voltage across the arc, it provides a more precise measurement of the voltage specifically at the point of the welding operation. Connecting the voltmeter across the power source terminals or anywhere else in the circuit may introduce additional resistance or voltage drop that can affect the accuracy of the measurement.Rate this question:
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14.
Lamellar tearing has occurred in a steel fabrication. What technique could have been used to find it before the weld was made?
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A.
X-ray examination
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B.
Liquid penetrant examination
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C.
Ultrasonic examination
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D.
It could not have been found by any inspection method
Correct Answer
C. Ultrasonic examinationExplanation
Ultrasonic examination is a technique that can detect internal defects such as laminations or tearing within the steel plates before welding. Ultrasonic waves are used to penetrate the material, and variations in wave reflections can indicate the presence of hidden defects.Rate this question:
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15.
Preheating a low alloy steel prior to welding to minimise the risk of:
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A.
Porosity
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B.
Excessive distortion
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C.
HAZ cracking
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D.
Lack of fusion
Correct Answer
C. HAZ crackingExplanation
Preheating a low alloy steel prior to welding helps to minimize the risk of heat-affected zone (HAZ) cracking. The HAZ is the area surrounding the weld that experiences high temperatures during the welding process. This rapid heating and cooling can lead to the formation of brittle microstructures in the HAZ, which increases the likelihood of cracking. By preheating the steel, the temperature of the HAZ is raised, reducing the thermal gradient and allowing for a slower cooling rate. This helps to prevent the formation of brittle structures and decreases the risk of cracking in the HAZ.Rate this question:
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16.
Typical temperature used for normalising a C-Mn steel plate are:
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A.
600-650ºC
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B.
1000-1100ºC
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C.
700-800ºC
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D.
880-920ºC
Correct Answer
D. 880-920ºCExplanation
The typical temperature used for normalizing a C-Mn steel plate is 880-920ºC. Normalizing is a heat treatment process that involves heating the steel plate to a temperature above its critical point and then cooling it in still air. This process helps to refine the grain structure of the steel, improve its mechanical properties, and relieve internal stresses. The temperature range of 880-920ºC is commonly used for normalizing C-Mn steel plates to achieve the desired results.Rate this question:
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17.
For GMAW the burn-off rate of the wire is directly related to:
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A.
Stick-out length
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B.
Wire feed speed
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C.
Arc voltage
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D.
Travel speed
Correct Answer
B. Wire feed speedExplanation
The burn-off rate of the wire in GMAW (Gas Metal Arc Welding) is directly related to the wire feed speed. The wire feed speed determines how fast the wire is fed into the welding arc. A higher wire feed speed results in a higher burn-off rate, meaning that more wire is consumed during the welding process. This affects the deposition rate and the amount of filler metal being added to the weld joint. Therefore, controlling the wire feed speed is crucial in achieving the desired weld quality and ensuring proper penetration and fusion.Rate this question:
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18.
For MMA welding of a 60mm wall nozzle to a 100mm wall vessel shell, preheat temperatures should be checked:
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A.
Before welding starts/restarts
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B.
On the shell and nozzle
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C.
At points at least 75mm from the joint edge
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D.
All of the above
Correct Answer
D. All of the aboveExplanation
The correct answer is "All of the above." Preheat temperatures should be checked before welding starts or restarts, on both the shell and nozzle, and at points at least 75mm from the joint edge. This is important to ensure that the temperature is appropriate for the MMA welding process and to prevent any potential issues or defects in the weld.Rate this question:
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19.
A crack running along the centreline of a weld bead could be caused by:
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A.
Use of damp flux
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B.
Lack of preheat
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C.
Arc voltage too high
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D.
Weld bead too deep and very narrow
Correct Answer
D. Weld bead too deep and very narrowExplanation
A crack running along the centreline of a weld bead can be caused by a weld bead that is too deep and very narrow. When the bead is too deep and narrow, it creates a high amount of stress concentration in the centerline, making it more susceptible to cracking. This is because the excessive depth and narrow width restrict the ability of the weld to properly distribute stress and strain, leading to the formation of cracks.Rate this question:
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20.
To improve resistance to service failure caused by cyclic loading, it is good practice to:
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A.
Use low heat input welding
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B.
Use steel with a low CEV
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C.
Ensure there are no features that give high stress concentration
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D.
PWHT the fabrication
Correct Answer
C. Ensure there are no features that give high stress concentrationExplanation
To improve resistance to service failure caused by cyclic loading, it is good practice to ensure there are no features that give high stress concentration. This means avoiding any design or fabrication elements that could lead to localized stress concentrations, such as sharp corners, notches, or abrupt changes in geometry. By minimizing stress concentration points, the material can better distribute the cyclic loading forces, reducing the likelihood of failure. This practice helps to improve the overall durability and longevity of the structure or component under cyclic loading conditions.Rate this question:
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21.
The use of low carbon austenitic stainless steels and stabiliser stainless steels will minimise the risk of:
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A.
HAZ cracking
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B.
Weld decay
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C.
Weld metal cracking
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D.
Distortion
Correct Answer
B. Weld decayExplanation
The use of low carbon austenitic stainless steels and stabiliser stainless steels helps to minimize the risk of weld decay. Weld decay refers to the corrosion that occurs in the heat-affected zone (HAZ) of stainless steel welds. It is caused by the depletion of chromium in the HAZ, which leads to the formation of chromium carbides and subsequent corrosion. By using low carbon austenitic stainless steels and stabilizer stainless steels, the carbon content and the formation of chromium carbides are reduced, thus reducing the risk of weld decay.Rate this question:
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22.
Which type of SAW flux is susceptible to breaking down into fine particles during circulation?
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A.
Fused
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B.
Neutral
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C.
Alloyed
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D.
Agglomerated
Correct Answer
D. AgglomeratedExplanation
Agglomerated SAW flux is susceptible to breaking down into fine particles during circulation. Agglomerated flux contains larger particles that are held together by a binder. However, during circulation, the binder can break down, causing the flux to disintegrate into smaller particles. This can lead to issues such as poor weld quality and increased spatter.Rate this question:
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23.
The maximum hardness in the HAZ of a steel will increase if the:
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A.
Heat input is increased
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B.
CEV is increased
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C.
Joint thickness is decreased
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D.
Basic electrodes are used
Correct Answer
B. CEV is increasedExplanation
If the CEV (Carbon Equivalent Value) is increased, it means that the steel contains a higher amount of carbon and other alloying elements. This increase in carbon content will lead to an increase in the maximum hardness in the Heat Affected Zone (HAZ) of the steel. Higher carbon content can result in the formation of harder and more brittle microstructures such as martensite, which can increase the hardness of the HAZ.Rate this question:
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24.
BS EN ISO 5817 (Level B) specifies the limit for excess weld metal (h) on a butt weld as:h<1mm+0.1b, but max. 5mm, b= weld width.In which of the following situations is the measured excess weld metal acceptable?
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A.
B = 10 measured excess weld metal = 2.5mm
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B.
B = 20 measured excess weld metal = 3.5mm
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C.
B = 35 measured excess weld metal = 4.5mm
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D.
B = 45 measured excess weld metal = 5.5mm
Correct Answer
C. B = 35 measured excess weld metal = 4.5mmExplanation
The measured excess weld metal is acceptable in the situation where b = 35 and the measured excess weld metal is 4.5mm. This is because according to the given specification, the limit for excess weld metal (h) on a butt weld is hRate this question:
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25.
A C-Mn steel is being welded by MMA and the electrode run-out lengths that have been used are much shorter than specified by the WPS. This deviation may give:
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A.
Increased risk of hydrogen cracking
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B.
Increased risk of solidification cracking
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C.
Lower values of HAZ toughness
-
D.
Higher values of HAZ hardness
Correct Answer
C. Lower values of HAZ toughnessExplanation
When welding a C-Mn steel using MMA, the electrode run-out lengths that are shorter than specified by the WPS can result in lower values of HAZ (Heat Affected Zone) toughness. The HAZ refers to the portion of the base metal that experiences a temperature increase during welding but does not melt. Inadequate electrode run-out lengths can lead to insufficient heat input, causing the HAZ to cool too rapidly. This rapid cooling can result in a brittle microstructure and decreased toughness in the HAZ, making it more prone to cracking and failure.Rate this question:
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26.
The first procedure prepared for a Weld Procedure Qualification test is a:
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A.
PWPS
-
B.
WPS
-
C.
WPQR
-
D.
WPAR
Correct Answer
A. PWPSExplanation
The correct answer is pWPS. A pWPS, or Preliminary Welding Procedure Specification, is the initial document prepared for a Weld Procedure Qualification test. It outlines the essential variables and parameters for the welding procedure, such as welding process, materials, joint design, and preheat temperature. The pWPS serves as a guideline for the actual welding process and is subjected to testing and evaluation to ensure it meets the required standards before a final WPS (Welding Procedure Specification) is established.Rate this question:
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27.
Transfer of material identification by hard stamping is sometimes not allowed for high integrity applications because it:
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A.
Is too slow
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B.
Can be a safety hazard
-
C.
May damage the material
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D.
Causes problems with coating operations.
Correct Answer
C. May damage the materialExplanation
Hard stamping involves using a stamp or die to imprint identification marks on a material. In high integrity applications, such as those involving critical components or safety-critical parts, hard stamping may not be allowed because it has the potential to damage the material. This can compromise the structural integrity and performance of the material, which is undesirable in such applications. Therefore, alternative methods of material identification that do not pose a risk of damage are preferred in these cases.Rate this question:
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28.
When welding thin plate distortion can be minimised by:
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A.
Welding from both sides
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B.
Using U preparations rather than V types
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C.
Using strongbacks
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D.
Using back-step welding
Correct Answer
D. Using back-step weldingExplanation
Using back-step welding is a technique where the welder starts at the end of the joint and welds towards the start, moving back and forth along the joint. This helps to distribute the heat evenly and reduces the risk of distortion in thin plates. By welding in this manner, the heat-affected zone is kept small, minimizing the amount of shrinkage and distortion that can occur.Rate this question:
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29.
Which of the following would be considered to be high heat input welding?
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A.
550J/mm
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B.
55J/mm
-
C.
5.5J/mm
-
D.
5KJ/mm
Correct Answer
D. 5KJ/mmExplanation
High heat input welding refers to a welding process that requires a significant amount of heat energy to be inputted into the weld joint. In this case, 5KJ/mm is the only option that meets this criteria, as it represents a high heat input of 5 kilojoules per millimeter. The other options, 550J/mm, 55J/mm, and 5.5J/mm, have significantly lower heat inputs and would not be considered high heat input welding.Rate this question:
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30.
Initiation of a TIG arc using high frequency spark may not be allowed because it:
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A.
Often causes tungsten inclusions
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B.
Can damage electronic equipment
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C.
Is an electrical safety hazard
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D.
Often causes stop/start porosity
Correct Answer
B. Can damage electronic equipmentExplanation
Initiating a TIG arc using high frequency spark can potentially damage electronic equipment. This is because the high frequency spark can create electromagnetic interference (EMI) which can disrupt the functioning of sensitive electronic devices. The EMI generated during the arc initiation can interfere with the signals and circuits in electronic equipment, leading to malfunctions or permanent damage. Therefore, it is important to avoid using high frequency spark for TIG arc initiation in order to prevent any harm to electronic equipment.Rate this question:
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FAQs
What happens when excessive arc voltage may cause in submerged arc welding? ›
Increasing arc voltage lengthens the arc so that weld bead width, reinforcement and flux consumption are increased as is the risk of arc blow.
Which physical test is more likely to reveal haz embrittlement? ›48 Which physical test is more likely to reveal HAZ embrittlement? Charpy impact.
How many levels are there in CSWIP? ›By providing three levels of certification this suite of welding inspection certification enables those who have experience in welding engineering to expand their knowledge and career prospects; while assuring employers of the competence of their inspectors, and the quality of the welds.
Which type of saw flux is more resistant to moisture absorption? ›In contrast, neutral and fused fluxes are less prone to moisture absorption due to their different composition and structure.
What happens if the voltage is too high in welding? ›If it is too high, the result will be a flatter bead and a concave weld profile. Voltage that is too high also can lead to undercut or a groove in the base material near the weld toe that isn't filled with weld metal.
Is CSWIP 3.1 hard? ›Hi there, the 3.1 is not particularly hard if you have some welding background, but the NDT knowledge and metallurgy are essential.
Which is better, CSWIP or AWS? ›CSWIP or AWS depends on the country you are working, I am not sure in Japan, but CSWIP is more widely accepted in Middle east, South-east and Australia. Does not mean AWS is not accepted.
What is the main purpose of submerged arc flux? ›The functions of the flux are: to assist arc striking and stability. to form a slag that will protect and shape the weld bead. to form a gas shield to protect the molten filler metal being projected across the arc gap.
What are the three types of flux used for SAW? ›In Japan, the SAW consumption ratio by industry is nearly the same as that for the world except for steel pipe, which accounts for a much lower share of SAW consumption. Table 1 shows the characteristics of the three types of SAW fluxes: fused, bonded and agglomerated.
Which type of electrode picks up moisture easily? ›Welding electrode coatings, especially low hydrogen electrodes, readily attract moisture in the coating. This moisture is a major cause of weld cracking and porosity. While plain water itself wouldn't damage the weld, the heat and arc break down water into its basic elements, hydrogen and oxygen.
What does increasing arc voltage do? ›
With the arc voltage increment, there is widening and flattening effect of the weld bead. For low voltages, the weld reinforcement has been increased, and for excessively high voltages results in porosity, spatter, instability in arc, and undercut formation [15].
What happens when voltage increases in welding? ›The Effects of Welding Voltage
Welding voltage primarily controls the arc length in welding, which is the distance between the molten weld pool and the wire filler metal at the point of melting within the arc. As the voltage is increased, the weld bead will flatten out more and have an increasing width-to-depth ratio.
With such low short-circuit power of the network, voltage fluctuations generated by arc furnaces will cause excessive disturbances, perceived, for example, as flickering light caused by lighting receivers.
What is the voltage of a submerged arc welder? ›In submerged arc welding, the welding current is fed just before the end of the consumable wire electrode. The low-current-carrying wire length allows for currents from 100 to 3600 A at voltages of 20–50 V, which leads to high deposition rates.