The resistance heating factors of energy storage welding machines include: current, welding time, and resistance. Among them, the welding current has a greater impact on heat generation compared to resistance and time. Therefore, it is a parameter that must be strictly controlled during the welding process.
The main reasons for current changes are voltage fluctuations in the power grid and changes in circuit impedance. Impedance changes occur due to changes in the geometric shape of the circuit or the introduction of different amounts of magnetic metals into the secondary circuit. For DC welding machines, changes in secondary circuit impedance have no significant effect on current.
To ensure the size of the weld nugget and the strength of the weld, welding time and welding current can complement each other within a certain range. To obtain a certain strength of weld, you can use high current and short time (hard conditions, also known as hard specifications), or you can use low current and long time (soft conditions, also known as soft specifications). Whether to use hard or soft specifications depends on the properties of the metal, thickness, and the power of the welding machine. There are upper and lower limits for the current and time required for metals with different properties and thicknesses, and these limits should be followed during use.
Resistance is the contact resistance between the workpieces, and the existence of contact resistance is transient, generally occurring at the beginning of welding, for two reasons:
There is a high-resistance oxide or dirt layer on the surface of the workpiece and electrode, which greatly impedes the flow of current. An excessively thick oxide and dirt layer may even prevent the current from conducting.
Under conditions of a very clean surface, due to the microscopic roughness of the surface, the workpiece can only form contact points on the rough surface locally. Current lines are concentrated at the contact points. The resistance at the contact points is increased due to the narrowing of the current path.
Suzhou Agera Automation Equipment Co., Ltd. is a manufacturer of welding equipment, specializing in the development and sale of efficient and energy-saving resistance welding machines, automated welding equipment, and industry-specific non-standard welding equipment. Agera focuses on improving welding quality, efficiency, and reducing welding costs. If you are interested in our energy storage welding machines, please contact us：leo@agerawelder.com
Post time: May-11-2024
