Application and prospects of laser welding in the automotive industry

The automobile industry is currently one of the main application areas of laser welding equipment in my country. A large part of the income of Han's Laser, Huagong Technology, and United Laser that has been listed currently comes from the laser welding market. Among them, in recent years, United Win Laser's customer revenue from the automotive power battery industry is close to 80% of its total revenue. At the same time, the main income of Hymson, Everbright Laser (discontinued) and Yifei Laser, which have applied for listing, also come from the automotive power battery industry.

Laser welding has become one of the important methods in industrial manufacturing because of its high energy density, small deformation, narrow heat-affected zone, high welding speed, easy automatic control, and no subsequent processing. The automobile manufacturing industry is the industry that uses laser welding technology on the largest scale in the current industrial production. The flexibility of laser welding machines meets the processing of various materials in automobiles, reduces automobile production costs, improves production efficiency, and brings huge economy to the automobile manufacturing industry. benefit. Laser welding technology is mainly used for automatic laser welding of automobile body-in-white top cover, multiple gear laser welding, airbag igniter laser welding, sensor laser welding, battery valve laser welding, etc. The details are as follows:

Chart 1 Application parts of laser welding technology in automobile manufacturing industry

Source: OFweek Industry Research Institute

Application of laser welding in the automotive field

In the automotive industry, laser welding is usually applied to the key positions of body welding and the parts with special requirements for the process. For example, it can solve the problems of welding strength, efficiency, appearance and sealing when used for welding the roof and side panels. ; Used for rear cover welding to solve the problem of right-angle overlap; used for laser tailored welding of door assemblies can effectively improve welding quality and efficiency. Different laser welding methods are often used for welding of different body parts. The following is a list of several laser welding methods commonly used in the automotive industry.

(1) Laser brazing

Laser brazing is mostly used for the connection of the top cover and the side wall, trunk lid, etc. Volkswagen, Audi, Peugeot, Ford, Fiat, Cadillac, etc. all use this welding method.

Chart 2 Application of laser brazing in the automotive industry

Source: OFweek Industry Research Institute

(2) Laser self-fusion welding

Laser self-fusion welding belongs to deep penetration welding, which is mainly used for roofs, side panels, car doors, etc. At present, many brand cars of Volkswagen, Ford, GM, Volvo and other manufacturers use laser self-fusion welding. The specific processing parts are as follows:

Chart 3 Application of laser self-fusion welding in the automotive industry

Source: OFweek Industry Research Institute

(3) Laser remote welding

Laser remote welding uses robots + galvanometers, remote beam positioning + welding, and its advantages are that compared with traditional laser processing, the positioning time is greatly shortened and the efficiency is higher. At present, it has gradually been promoted in Europe and the United States.

Chart 4 Application of laser remote welding in the automotive industry

Source: OFweek Industry Research Institute

Features of laser welding car body

1. Non-contact processing

The most important advantage of laser welding in automobile manufacturing is embodied in advanced non-contact processing methods. Traditional processing methods such as screw fastening and adhesive connection cannot meet the requirements of precision and robustness in modern automobile manufacturing, and the application of new materials also makes traditional processing methods slightly disadvantageous. Laser welding is non-contact. In the process of processing, precision welding can be achieved without touching the product. It has achieved leapfrog progress in the robustness, seamlessness, precision and cleanliness of the connection.

2. Laser welding improves the weight of automobiles

The use of laser welding can replace castings with more stamping parts in automobile manufacturing, and use continuous laser welding seams to replace scattered spot welding seams, which can reduce the overlap width and some strengthening parts, reduce the volume of the body structure itself, thereby reducing The weight of the body is reduced, and the requirements for energy saving and emission reduction of automobiles are met.

3. Improve body assembly accuracy and rigidity

There are hundreds of parts in the body and chassis of a car. How to connect them has a direct impact on the rigidity of the vehicle body. Laser welding can almost all metal materials of different thicknesses, grades, types and grades. Connected together, the accuracy of welding and the assembly accuracy of the body are greatly improved, and the rigidity of the body is increased by more than 30%, thereby improving the safety of the body.

4. Laser hybrid welding improves process stability

Compared with pure laser welding technology, the use of laser hybrid welding technology can greatly improve the connection ability of sheet metal gaps, so that enterprises can make full use of the process stability of arc welding during laser high-speed welding.

In addition, the use of laser welding can also reduce the cost of stamping and assembly in the car body manufacturing process, shorten the production cycle, reduce the number of parts, and improve the degree of body integration. Laser welding parts, the welding part has almost no deformation, the welding speed is fast, and no post-weld heat treatment is required. At present, laser welding parts have been widely used, such as transmission gears, valve lifters, door hinges, etc.

Analysis of the development status of China's automobile industry

Since 2011, the development of my country's automobile industry has turned from rapid growth to steady growth. In 2018, China's automobile industry has been operating smoothly. Affected by policy factors and macroeconomics, its production and sales were lower than expected at the beginning of the year. The annual automobile production and sales were 27.81 million. In 2019, the production and sales of automobiles were 25.721 million and 25.769 million respectively, down 7.5% and 8.2% year-on-year, respectively, ranking first in the world for 11 consecutive years. China is a big country in the automotive industry, and the transformation and upgrading of the automotive industry is developing steadily, which plays a very important role in promoting the application of advanced laser welding equipment in the automotive industry.

Figure 5 China's auto production and sales volume from 2014 to 2019

Data source: China Association of Automobile Manufacturers, OFweek Industry Research Institute

In 2019, in the process of transformation and upgrading of my country's automobile industry, it was affected by factors such as Sino-US economic and trade frictions, switching of environmental protection standards, and decline of new energy subsidies. Over the past year, production companies have taken the initiative to adjust and responded actively. In the second half of the year, they showed strong self-recovery ability, and the industry as a whole remained within a reasonable range. In this huge market, consumers can pay attention to many international auto brands and vehicle companies, but the development of complete vehicles is precisely due to the development of parts and components companies. At present, the scale of my country's parts and components industry has ranked among the top in the world, among which parts and components companies with foreign-funded backgrounds occupy the mid-to-high-end market, while domestic-funded parts and components companies mainly occupy the low-end market.

Due to the weak technical research and development capabilities of domestic auto parts companies, it is difficult to support the upgrading and innovation of vehicle technology. Therefore, domestic vehicle companies and upstream parts supply companies are bound to carry out equipment and technological process transformation and upgrading, and realize the improvement of vehicle and parts companies. In-depth cooperation will greatly promote the application of laser welding, laser cutting and other equipment in the automobile manufacturing industry.

Analysis on the Application Prospect of Laser Welding in Automobile Industry

Under the background of the steady development of my country's automobile industry, with the demand for lightweight automobiles, breakthroughs in domestic laser welding technology, and increased application penetration, the future application of laser welding equipment in the automobile industry has broad prospects, as follows:

1. The demand for lightweight cars

The lightweight of automobiles makes laser welding technology more and more important and widely used. The "Action Plan to Promote the Development of the Automotive Power Battery Industry" mentions the need to develop lightweight technology for automobiles. 2016-2020 is the first stage, focusing on the development of ultra-high-strength steel and advanced high-strength steel technology, including material performance development and lightweight Design method, molding technology, welding process and test evaluation method, etc. High-quality and efficient laser welding key processes and complete sets of equipment are important technical guarantees for achieving lightweight, high-safety, flexible and efficient production of automobiles. Compared with the traditional resistance welding in the manufacturing process, laser welding can not only compress the volume of the body structure itself, reduce the weight of the body, and reduce the fuel consumption of the car, but also can reduce the loss of process and production materials, and improve the production efficiency.

2. Breakthrough in domestic welding technology

The domestic automobile welding technology has made a breakthrough, breaking the international monopoly. In recent years, domestic auto companies have increasingly adopted automatic welding production lines, but this market is basically monopolized by ABB, KUKA, and COMAU. Domestic companies lack the right to speak in the process of cooperation, and companies are less enthusiastic about laser welding. . In 2016, the "High-quality and efficient laser welding and cutting key processes and complete sets of equipment in automobile manufacturing" project independently developed by Huagong Laser in cooperation with Huazhong University of Science and Technology, Shenlong, General Motors and many other downstream car companies was awarded the first class of national scientific and technological progress. Award for realizing the localization of key laser welding and cutting processes and complete sets of equipment in the field of automobile manufacturing, breaking the history of over 40 years of foreign monopoly in this field, and marking a major breakthrough in my country's advanced laser manufacturing technology in the field of automobile manufacturing. In the future, with the further breakthrough of domestic laser welding technology, the application of laser welding technology in the field of automobile manufacturing in my country will be more.

3. Increase in application penetration

The penetration rate of laser welding in my country's automobile industry has huge room for improvement. The Germans were the first to apply laser welding technology to automobiles. In the mid-1990s, BMW used laser welding robots to complete the first welding seam of BMW5 series cars, with a total length of 12m. Subsequently, the roofs of brands such as Audi, Sagitar, Golf and Passat adopted laser welding technology. Companies such as GM, Toyota, Ford, BMW, and Mercedes-Benz have successively adopted laser welding technology. At present, the application rate of domestic laser welding in the automotive industry is as large as 20%-25%, while the penetration rate in developed countries in Europe and the United States has reached more than 60%. It is expected that the domestic laser welding application rate will reach the same level as abroad in the future. The income of laser welding equipment is considerable, and the application of laser welding machines in my country's automobile industry has huge room for improvement.