Inventory Of 15 Common Welding Methods, Core Welding Knowledge: Detailed Explanation Of Welding Process Classification And Application

Inventory of 15 common welding methods, core welding knowledge: detailed explanation of welding process classification and application

In terms of welding quality, the core lies in the control of the heat-affected zone. However, riveting relies on cold working to avoid material deformation. The two have completely different effects on the properties of the base metal. Next, we will start with 15 welding methods, combined with the selection of welding materials and the experience accumulated in the actual operation process, to help you understand the logic of selection.

Detailed explanation of fusion welding process and influence of heat affected zone

Fusion welding uses high temperatures to melt the joint metal, and the heat-affected zone is key to quality. The equipment of manual arc welding is relatively simple, and it is suitable for on-site repair. However, its heat input is large, and the width of the heat affected zone can reach 2 to 5 mm, which can easily cause the grain coarsening of low carbon steel. Submerged arc automatic welding has high efficiency, the flux layer can slow down the cooling rate, and the heat-affected zone is relatively narrow . The welding heat-affected zone vs. the impact of riveting cold processing on the material is suitable for long welding seams of boilers and ships. In 2025, a shipyard used this process to weld a 3,000-meter-long hull weld.

In gas shielded welding, the heat affected zone produced by argon arc welding is small, and it is suitable for welding stainless steel and non-ferrous metals. For example, in 2024, an aviation factory used argon arc welding to weld titanium alloy wing brackets, and its heat affected zone was controlled within 0.5 mm. Laser welding has extremely high precision, and its heat-affected zone is only between 0.1 and 0.3 mm. It is the preferred method for precision joints in the electronics industry, such as the welding of mobile phone battery poles.

Pressure welding for solid phase connections that avoid thermal effects

Pressure welding does not need to melt the base metal and avoids the heat-affected zone problem from the root. Resistance welding is used for spot welding oil tanks. The welding time is only 0.1 seconds and the heat-affected zone is almost non-existent. However, the strength of the joint relies on pressure control. Friction welding uses rotation to generate heat. In 2023, an automobile factory used this method to weld 100,000 copper-aluminum transition joints. The heat-affected zone was only 0.2 mm, and the strength was 30% higher than flash butt welding.

The welding method for connecting microelectronic devices with silk foil is ultrasonic welding. In 2025, there was a chip factory that used ultrasonic welding to weld gold wires without fillers and the heat-affected zone was zero. As for the manufacturing of composite panels, explosive welding is used, which achieves this purpose with the impact of explosives. In 2024, a petrochemical company produced 500 square meters of titanium steel composite panels through explosive welding. The heat-affected zone is only 0.8 mm, which is suitable for large-area dissimilar metal connections.

Brazing operates at low temperatures to avoid material deterioration

The brazing temperature is lower than the melting point of the base material. The heat-affected zone of welding vs. the impact of riveting cold processing on the material . Its heat-affected zone is extremely small, so it is suitable for precision connections. Among them, soldering has a melting point lower than 450°C and is used for instrument wire welding. For example, in 2024, an instrument factory used soldering to weld 100,000 sensor wires. Its heat-affected zone is only 0.1 mm, and its conductive performance is stable. The melting point of brazing is higher than 450°C, and the joint strength is high. For example, in 2025, a bicycle factory used brazing to weld titanium alloy frames, and the heat-affected zone was controlled to be above 0.3 mm.

During the brazing process, the control of the heat-affected zone depends on the selection of brazing material. When soldering, use tin-lead solder, which cools quickly and the grains of the base metal will not change. When brazing, silver-based solder is used and the temperature rise rate needs to be controlled. In 2023, a tool factory used brazing to weld carbide cutter heads, and the heat-affected zone was only 0.2 mm, which avoided cracking of the cutter heads.

The selection of welding materials directly affects the heat affected zone

There are acidic and alkaline welding rods. Alkaline welding rods have low hydrogen characteristics and have a lower risk of embrittlement in the heat-affected zone. However, they need to be dried at a temperature of 350 to 400°C before use. In 2024, a bridge project used alkaline welding rods to weld 200 tons of steel structures, and the width of the heat-affected zone was controlled within 1.5 mm. There are two types of welding wires: solid and flux-cored. Flux-cored welding wire has the characteristics of small spatter, and its heat-affected zone is more beautiful in shape, making it suitable for all-position welding.

In the heat affected zone, argon is used as a protective gas in argon arc welding, which can reduce the scope of the heat affected zone; CO₂ is suitable for welding of low carbon steel, but its heat input is slightly larger. A gas mixture of 80% Ar, 15% CO₂ and 5% O₂ is a "universal combination" method for low carbon steel welding. In 2025, a car factory used this gas to weld 5,000 chassis parts. At this time, the width of the heat-affected zone was only 0.8 mm, which was reduced by 30% compared to pure CO₂.

Practical selection principles to deal with heat-affected zone issues

The first principle is to match the characteristics of the base metal. For stainless steel, argon arc welding is the first choice because its heat-affected zone is small and it has anti-corrosion properties. In 2024, a chemical plant used argon arc welding to weld 304 stainless steel pipes. The width of the heat-affected zone was 0.6 mm, thus avoiding intergranular corrosion. It is also very critical to fit the working conditions. In the environment created by high temperature and high pressure, alkaline electrodes and gas shielded welding must be used. Just like during boiler welding, the hardness of the heat affected zone needs to be controlled below HV200.

To balance efficiency and cost, if mass production is carried out, then choose submerged arc welding or robotic gas shielded welding. The heat-affected zone is controllable and the efficiency is high. If small batch repairs are required, manual arc welding must be used. In 2023, a construction site used this process to weld a 50-meter crack. The width of the heat-affected zone was 2 mm, and it was easy to operate.

Comparison of the differences between heat affected zone and riveting cold working

When connecting aluminum alloy skins, the welding heat-affected zone will cause changes in the metallographic structure of the base metal. For example, the hardness of the heat-affected zone of low carbon steel may increase to HV250, which will cause embrittlement of the body. As for riveting, it falls within the category of cold working and does not produce a heat-affected zone. In 2024, an aviation factory will use riveting to connect aluminum alloy skins to avoid thermal deformation, and the joint strength can be maintained at more than 90% of the base material.

However, riveting has limitations and is not suitable for thick plates or high-strength steel. The welding heat-affected zone can be controlled by preheating or post-heat treatment. For example, in 2025, a bridge project will temper the welded joints at 650°C, and the hardness of the heat-affected zone dropped to HV180. Riveting relies on mechanical force. In 2023, a car factory used riveting to connect body steel plates. There was no microstructural change in the cold working area.

If you encounter an instance of failure due to overheating affected zone during welding or riveting selection, you are welcome to share your specific experience in the comment area, and like and bookmark this article so that you can check the relevant tips for welding material selection at any time!