Welding Knowledge 3: Welding Equipment - xlweld.com
Third, welding equipment
1. What is welding power?
A: The welding machine, the supply of welding power required and has suitable for welding electrical characteristics of the device known as welding power.
2. Why is there a special requirement for arc welding power? What are the requirements?
A: In order to ensure the welding arc stable combustion and adapt to a variety of welding process requirements, arc welding power supply has the following special requirements:
<1> The static characteristics (or external characteristics) of the arc welding power supply - that is, the relationship between the steady-state output current and the output voltage, the descending characteristic (constant current characteristic) and the flat characteristic (constant voltage characteristic).
A, electrode arc welding, TIG
-welding.html target='_blank'>TIG Welding and carbon arc gouging power of the external characteristics of the decline (constant current) characteristics;
The external characteristics of the B, CO2 / MAG / MIG
arc welding power supply are flat characteristics (constant voltage characteristics). <2> Dynamic characteristics of arc welding power - When the load state changes instantaneously (eg, short-circuit transition of droplet, particle transition, jet transition, etc.), arc welding power output current and output voltage and time relationship Characterization of the load transient response capacity (ie, dynamic response capability), referred to as "dynamic characteristics."
<3> No-load voltage - Voltage displayed before the arcing power supply.
<4> Adjustment characteristics - change the external characteristics of the power supply to meet the requirements of welding specifications.
3. Why does the arc voltage change when the arc length changes?
A: The arc welding power by the external characteristics of the decision, the longer arc, the higher the arc voltage; the shorter the arc, the lower the arc voltage.
4. Why is the current display value changing when the wire length is changed during CO2 welding?
A: The longer the wire extension length (ie, the dry elongation), the greater the amount of resistance of the wire, the greater the current consumed by the resistance heat, the smaller the value of the welding current, and the smaller the actual welding current. So the wire length is generally set in the range of 12 - 20mm.
5. Why is the CO2 and MAG / MIG welded, the welding current and arc voltage to be strictly matched?
A: CO2 / MAG / MIG welding, adjust the welding current - that is, adjust the feeding speed of the wire; adjust the arc voltage - that is to adjust the melting speed of the wire; Obviously, the welding speed and feeding speed must be equal to ensure Arc stable welding.
<1> When the welding current is constant, the adjustment arc voltage is high, the melting speed of the welding wire increases, the arc length increases, the droplet can not be the normal transition, the general large particles fly out, the splash increases. <2> When the welding current is constant, the adjustment arc voltage is low, the melting speed of the welding wire decreases, the arc length becomes shorter, the wire is inserted into the molten pool, the splash is large and the weld is bad.
<3> welding current and arc voltage the best match effect: the droplet transition frequency is high, the smallest splash, weld appearance.
6. What is arc stiffness?
A: In the heat shrinkage and magnetic contraction effect, the arc along the axial direction of the electrode straight.
7. Why is the welding arc partial blowing phenomenon?
A: During the welding process, due to the interference of the airflow, the role of the magnetic field or the eccentricity of the electrode, the arc center deviates from the electrode axis.
8. What is magnetic partial blowing?
A: DC arc welding, due to the welding circuit in the role of electromagnetic force generated by the arc blowing. By changing the ground wire position or reduce the welding current and change the electrode angle, can weaken the impact of magnetic bias.
9. What is the self-regulation feature of the CO2 power arc system? Why CO2 welding with thin wire?
A: constant speed wire feeding system, when the arc length changes caused by changes in current and melting speed, so that the role of arc length recovery of the power arc system itself to adjust the role. The smaller the diameter of the wire used, the stronger the regulation of the arc itself, the more stable the arc, the less the splash. This is the principle of thin wire welding with CO2. Tangshan Panasonic
CO2 welding machine through advanced control technology, the arc of its own regulation of the best, the most stable performance.
10. What is the load duty cycle of the welder?
A: The duty cycle refers to the ability of the welding power to work continuously at a constant current. GB requirements manual welding rated load duration of 60%, automatic or semi-automatic 60% and 100%. Such as: 500KR2 welding machine rated rated at 60% of the rated current is 500A, the actual load duration of 100% (automatic welding), the maximum welding current ≤ 387A.