One, multiple choice
1. In order to obtain the required surface surfacing layer structure and save alloying elements, ( B ) must be reduced as much as possible.
A. fusion ratio
b. dilution rate
c. Deposition rate
D. deposition rate
2. The function of the arc stabilizer is to improve the (A) of the electrode and improve the arc stability of the welding arc.
A. Arc ignition performance
B. Pressure coating performance
C. Removal of slag
D. Anti-porosity performance
3. The essential reason for laminar tearing of steel structures is the type, quantity and distribution of (A).
A. non-metallic inclusions
b. nitride
c. Hydride
D. oxide
4. During brazing, (B) will not weaken the capillary action of the solder.
A. Small joint clearance
b. Weldment surface is not very smooth
c. There is grease on the surface of the weldment
D. Excessive dissolution of base metal brazing filler metal
5. (D) Suitable for welding aluminum and aluminum alloy sheets, all-position welding.
A. Melting electrode argon arc welding
B.CO2 gas shielded welding
C. Electrode arc welding
D. Tungsten pulse argon arc welding
6. The plasma arc requires the power supply to have (B) external characteristics.
A. Slow down
B. steeply descending
c. Horizontal
D. rise
7. The (C) generated by welding of welded components is called welding stress.
A. Deformation force
B. Prestress
C. Internal stress
D. Atomic bonding force
8. When arc cold welding gray cast iron, (C) is generally obtained.
A. Gray cast iron weld
B. Ductile iron welds
C. Non-cast iron welds
D. Malleable Iron Welds
2. Judgment questions
1. In order to avoid the fluctuation of the specimen gap and the problem of the gas cutting surface hardened layer, the bevel of the specimen for the inclined Y-shaped groove butt crack test should be processed by mechanical cutting.
right
2. The bending test of the welded joint is used to check the tensile strength of the joint and display defects.
wrong
3. Before cleaning the brazing workpiece, there is no need for degreasing and mechanical cleaning.
wrong
4. The productivity of arc wire spraying is proportional to the spraying current.
right
5. The DC power supply is easier to keep the arc burning stably than the AC power supply.
right
6. After the butt crack test of the inclined Y-shaped groove, detect and dissect the specimen, and calculate the surface crack rate, center crack rate, section crack rate and root crack rate respectively.
wrong
7. Air plasma cutting using compressed air as cutting gas can cut low alloy steel.
right
8. When the pipeline is welded downwards, undercut defects are not allowed.
wrong
9. The deformation of the weldment without external rigid constraints is called free deformation.
right
10. Boilers and pressure vessels are characterized by harsh working conditions, prone to accidents and extensive use and require continuous operation.
right
The above are the simulated questions and answers for the theoretical knowledge of welders in Jiangxi Province in 2022. Xiaobian and Youtibao will continue to update the simulated questions and answers for the welder's test. If you need it, don't miss it. I also hope that all candidates can achieve good results in the welder technician examination.