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Influence of welding current of energy storage welder on welding quality [CD07]
Dec 26,2023
We often use all kinds of electrical appliances in our daily life. The television set feels warm after it works for a while. The computer and mobile phone would also feel hot after running for a period of time. Even the refrigerated refrigerator also heats up. Is it amazing?
This means that when current flows through a resistive conductor, some of the electrical energy is converted into internal energy, causing the conductor to heat up. This is the thermal effect of electric current. There is a famous law in physics which describes the thermal effect of electric current. It is called Joule's law.
Joule’s law states that the heat generated by a current flowing through a conductor is directly proportional to the square of the current, the resistance of the conductor, and the time for which the current flows.
Mathematically, Joule’s law can be expressed as:
Joule heating Q=I²R*t
Where: I = the current flowing through the material (in amperes, A)
R = the resistance of the material (in ohms, Ω)
t = the time the current flows through the material (in seconds, S)
To calculate the amount of Joule heating generated by a current flowing through a material with resistance, you would need to know the values of I, R, and t, and then use the formula above to determine the amount of heat generated. For example, if a current of 2 amps flows through a resistor with a resistance of 10 ohms for 5 seconds, the Joule heating generated would be:
Joule heating Q = 22 * 10 * 5 = 200 Joules
So, in this case, 200 Joules of heat would be generated by the electrical current passing through the resistor.
According to Joule's law, the heat produced by welding is directly proportional to the square of welding current. The influence of welding current on heat is the greatest. Therefore, in the welding process, the current parameter must be strictly controlled.
The main causes of current change are voltage fluctuation of power grid and impedance change of secondary circuit of AC Welder. The impedance changes are due to changes in the loop geometry or the introduction of different amounts of magnetic metals into the secondary loop.
The current must melt the projection before it collapses completely, and the recommended current should be the maximum current not to squeeze out too much metal at the appropriate electrode pressure. For a certain size of projection, the amount of metal extruded increases with the increase of current. Increasing amplitude modulation current can reduce the extruded metal. Like spot welding, the properties and thickness of the weld metal are still the main criteria for selecting the welding current.
For multi-spot projection welding, the total welding current is approximately the current required for each projection multiplied by the number of projections. However, some adjustments may be necessary to take into account the projection tolerance, the workpiece shape, and the impedance of the secondary circuit of the welder.
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Wuxi HAIFEI Intelligent Equipment Co., Ltd.
Wuxi HAIFEI Welding Equipment Co., Ltd.
Add: 28 Shuiyun Road, Yuecheng, Jiangyin, Jiangsu Province, China. (Postal Code: 214404)
Mobile: +86 18915302352
Email: wushijie@jshaifei.com