Introduction of Resistance Welding Technology

In modern industrial manufacturing, welding technology is undoubtedly one of the significant methods for joining metal materials. Among these methods, resistance welding, as an efficient and environmentally friendly welding technique, has gained extensive usage in various sectors such as automotive parts manufacturing, aerospace, and electronic products, due to its distinctive process characteristics.

Basic Principles of Resistance Welding

Resistance welding utilizes electricity to generate heat at the contact surface of the welding parts, melting the metal and joining the parts together through compression. The working principle can be summarized as "resistance heat, heat causes melting, and continuous force forming joints."

· Resistance heating: When two metal parts to be welded are in close contact, a high current (thousand to tens of thousands of amperes) flows through the contact surface. Due to the minimal resistance of the contact surface, a large amount of heat is generated when the current passes through.

· Heat causes melting: This heat rapidly causes the metal in the contact area to reach a molten state. 

· Continuous force forming joints : Under continuous force, the molten metals penetrate and diffuse into each other, and forming a strong welded joint after cooling.

Classification and application of resistance welding

Resistance welding technology can be divided into many types according to specific process characteristics and implementation methods, and each type has its specific application scenarios and advantages.

Spot Welding

Spot welding is one of the most common forms of resistance welding, primarily utilized for joining thin plate structures, such as in the production of automobile bodies. During the spot welding process, the electrode acts on a specific point on the workpiece through an instantaneous high current to form a small molten core, thereby achieving a connection. Spot welding offers advantages of high production efficiency, low cost, and easy automation. However, it is not suitable for applications that demand exceptionally high strength requirements for the welded joint.

Seam Welding

Seam welding is a continuous form of spot welding and is primarily utilized for the creation of continuous welds products, such as the edge sealing of metal containers. During the seam welding process, the electrode moves along the predetermined weld trajectory while simultaneously applying current and pressure to form a continuous weld line. Seam welding is especially well-suited for welding applications that require high air tightness or water tightness.

Projection Welding

Projection welding is a specialized method of resistance welding that increases the contact area and resistance by preforming projection points on the workpiece to be welded, thereby improving welding efficiency and quality. Typically, this method is employed for welding fasteners such as nuts and bolts to metal plates, and has the characteristics of small welding deformation and high strength.

Butt Welding

Butt welding is a welding technique that directly connects two metal rods, tubes, etc. of the same or different materials, melts their end faces through resistance heating, and presses them together. Butt welding is suitable for connecting metal parts with larger cross-sections, such as the manufacture of wires, cables, and steel pipes. Butt welding technology can achieve higher joint strength and good electrical and thermal conductivity.

Resistance welding technology plays an essential role in modern manufacturing with its high efficiency, energy saving and environmental friendliness. By deeply understanding the basic principles of resistance welding and its various applications, we can better select suitable welding processes, optimize production processes and improve product quality. With the continuous advancement of science and technology, resistance welding technology is also continuously evolving and progressing towards a higher level of automation and intelligence, providing strong technical support for the transformation and upgrading of the manufacturing industry.