Looking at the Development Trend of Welding Technology at Home and Abroad from Welding Exhibition

With the rapid development of the world's manufacturing industry, welding technology has become more and more widely used, and the level of welding technology is also getting higher and higher. New welding process methods continue to emerge, and professional welding equipment is changing with each passing day. At the same time, domestic and foreign welding equipment manufacturers have also demonstrated their strength through various means, in particular through exhibitions with a wide variety of products and advanced technologies.

Throughout the three major welding exhibitions in 2009, the 14th Beijing Essen Welding and Cutting Fair held in Shanghai in June 2009 and the 17th German Essen Welding in Germany in September 2009 in Essen The cutting exhibition and the 23rd China Welding Exposition held in Tianjin in October 2009 are deeply impressed by the development trend of welding technology at home and abroad as well as the new demands and trends of welding production development. The role of core technology has been demonstrated. With the development of numerical control and power supply, laser welding technology has become a major highlight and robot applications have become more popular. It can be considered that the world welding technology has reached a new level and has made new progresses in terms of efficiency, automation, and environmental friendliness; the types of welding materials are more abundant, welding automation, high efficiency, and cleanliness are more prominent; the integration of welding technologies The cost is lower and welding is more extensive for industrial services. At the same time, manual, rough, dirty and low-speed welding has basically been eliminated, replaced by automatic, precise, clean and efficient

1 Development trend of inverter welding technology

Several aspects of inverter welding machines continue to develop in depth: increased popularity, enhanced power production capabilities, and miniaturization.

Increased popularity: The participation rate of inverter welding machines is getting higher and higher, and the exhibition area is becoming wider and wider. At this year's show, almost all major companies displayed a variety of inverter welding machines and new technologies and new products in a large battle, but their respective varieties, power, performance, functions and manufacturing levels are different. In addition, the variety, performance, function, welding method and application range of inverter welding machine have also been improved, increased and expanded.

Power manufacturing capacity enhancement: In the past, people believed that inverter welding machines were mainly suitable for small and medium power applications due to their advantages of compactness, ease of movement, and energy saving. At this year's show, many companies exhibited 1,000-amps of technical products.

Miniaturization: Minimize the power of the inverter welding machine by increasing the frequency and using high-performance magnets, optimizing the structure, etc. For example, the small welder used for thin-plate welding in the assembly and maintenance work where the welding position changes frequently is only 3.4kg.

At the exhibition, inverter welders appeared on the stands of all welder exhibitors, indicating that inverter welders have become the mainstream trend in the welding machine industry. At present, the inverter welding machine has matured on the basic technical level. The current technological competition is mainly reflected in the extension of the inverter-related power supply technology and the intensification of welding technology related to the inverter welding machine.

1.1 Soft Switch Technology

The technology of soft switching power supply in foreign inverter welders is not very common. In particular, the majority of 20KHz inverter welders still use hard switches. However, the capacity of the switching devices they use is much larger than that of domestic welders, so as to ensure The high reliability of the inverter power supply. This is due to the different manpower costs, as the cost of manufacturing and assembling the additional electromagnetic components required for the soft-switching circuit will exceed the material cost of increasing the switching device capacity where the labor cost is higher. Foreign soft-switching power supply technology is mainly aimed at high-frequency high-power welding machines working at 60-120 KHz, mainly to improve the power supply's response speed and facilitate more precise waveform control processes.

1.2 transformer material and its structure

Inverter transformer is the key device in the inverter welding machine. In this regard, the domestic high-power welders use a large proportion of amorphous cores, while most foreign countries also use ferrite cores. At present, the most frequently used inverter frequency of 20 KHz, amorphous iron core should be said to have more material cost advantages than ferrites, but due to the material properties, amorphous cores can only be supplied in a ring-shaped manner. Automatic winding of coils. Most foreign companies use ferrite cores rather than switch to amorphous cores, and domestic companies use amorphous cores widely for reasons of material cost.

1.3 Digital Control Promotes Upgrade and Development of Welding Technology

Five years ago, the digitally controlled welding machine was only the “top-of-the-line technology” of a few internationally renowned companies. From the perspective of this year's show, digital control is commonplace in the world, and digital control welders are no longer selling points. Driven by Finnish KEMPPI and Austrian Fronius, digital welding machines have entered the stage of large-scale production.

The high response speed of the inverter power supply provides an ideal power platform for welding control technology. The application of digital technology in welding power supplies further improves the level and operability of power supply control technology. The digital control of the inverter welding machine will undoubtedly have a strong development, because it greatly simplifies the circuit structure in the control, improves the stability of the welding machine control system, and facilitates the application. At present, the biggest difference between domestic digital welding machines and foreign digital welding machines lies in the welding process performance. It can be said that the biggest selling point of digital welding machines is not the digital technology itself, but advanced welding technology. At the same time, the greatest advantage of digitalization lies in the fact that it can carry advanced welding technology when combined with inverter welding machines.

1.4 The relationship between inverter welding machine and welding process

The impact of inverter welding machine on the welding machine industry is undoubtedly a revolution in power supply technology. But for the entire welding field, it is not so much a revolution in power supply technology as it is a revolution in welding process technology. It can be said that the inverter welding machine has promoted the deepening of the welding process technology.

In particular, digital technology is installed on the technology platform of the inverter welding machine to further change the technical status of the welding machine industry. Through the exhibition, it can be seen that the combination of simple power supply technology and advanced welding technology has become a trend. Researching the welding arc behavior will become an important aspect of the technical development of the future welding machine industry.

1.5 Dependence on Digital Control of Wire Feeder

The greatest advantage of the digitally controlled inverter welding machine is reflected in the GMAW (Metal Shielded Gas Welding) process. Therefore, besides the power supply problem, the control of the wire feeder is also very important. If there is no stable wire feed speed, many advanced control methods cannot be implemented. For example, the core issue of pulsed MIG is the reasonable matching between current waveform and wire feed speed. At present, the main gap of domestic pulse MIG welding machines is not in the power supply but in the wire feeder. Similar foreign products are wire feeders with speed feedback control, while most domestic wire feeders are still using voltage feedback control. With the improvement of the welding process requirements, the requirement for the wire feeder is not only the speed stability, but also the request for the response speed is getting higher and higher. For example, the core of CMT technology is the back-drawing control of welding wire, which also plays a key role in arc ignition technology. The digitally controlled AC servo motor has replaced the traditional DC motor in the wire feeder in the high-grade welding machine. It can be seen that the digital control of the inverter welding machine is also a development trend from the power supply part to the wire feeder.

1.6 Digital Technology for High Performance and Versatility

As we all know, digital technology can improve the control system's interference, control accuracy, and thus improve the welding machine welding accuracy, reliability and stability of the whole performance. At the same time, through the transformation of the external characteristic curve, output current waveform, dynamic characteristics parameters, etc., to achieve a variety of welding methods, a variety of welding consumables, multi-function, multi-welding parameters of the adjustment and the best matching of the control, in the welding machine At the same time as making “boutique”, the welding process and the weldment are also made “exquisite”. Forunis' CMT (Cold Metal Transition) welding system is well explained in this respect. The CMT droplet transfer mode is novel, and compared with the traditional welding process, the transitional droplet temperature is relatively low, and the dissimilar metal connection can be realized. The melting and transition of the welding wire can be two relatively independent processes, respectively, and the energy of the welding line is controlled. More flexible. Through precise arc length control, the CMT process combines pulsed arcs to practice spatterless welding, which greatly reduces the heat input to the weld. By controlling the pulsed arc to affect the heat input, the droplet transfer in the no-current state can be realized; the melting time of the base metal is very short, the arcing speed is increased twice, the heat input is low, the welding distortion is small, the bridging capacity is significantly improved, and the welding performance is excellent. Weld appearance is beautiful.

It is understood that many domestic universities are actively carrying out research on cold metal transition welding systems.

2High-speed, high-efficiency gas shielded welding

In addition to the automation of welding robots, there is a great deal of exhibition and extensive application of melting electrode welding. In addition to individual special cases, MIG welding is almost entirely a MIG/MAG welding machine, which meets the needs of high-speed and high-efficiency welding of thin plates for containers and other industries. The TANDEM welding system exhibited by the German company Cruz in Zhuhai, welding speed of 2~3mm thin plate can reach 6m/min, welding efficiency of welding thick plate above 8mm can reach 24kg/h. Some requirements for control line energy in welding Gas-shielded welding is the latest alternative to submerged-arc welding in the case of low-alloy high-strength steels and other materials.

3 Development trend of CO2 welding equipment

3.1 Inverse change, digitization, intelligence, automation

In order to achieve efficient welding, the past was limited to changing welding parameters and shielding gas. Today, the inverter welding machine has shown great vitality, because its high operating frequency makes the welding machine has the characteristics of small size, light weight, energy saving, material saving, reduced consumption, fast dynamic response, high efficiency, and good welding performance. , is gradually becoming the mainstream of arc welding power. It is on the platform of the inverter welding power supply that computer technology is used to solve the higher technical requirements of gas protection welding with modern scientific methods.

At present, domestic welding technology research institutes and national manufacturers such as Beigong University and Chengjin Welding Institute are actively exploring “How to apply new methods to improve welding quality, achieve 'less splashing and no spatter', 'less stomata and no porosity'”, "How to apply new methods to reduce welding costs and achieve the fastest welding speed with minimal energy input." Therefore, we actively promoted the research and development of digital inverter gas welding machines. Using digital control instead of analog control is the scientific road for the development of gas shielded welding machines.

3.2 New AC Short-Circuit Transition Welding Method

In order to meet the low heat input and low spatter CO2 welding requirements, Japan's OTC Corporation and Panasonic Corporation respectively introduced the AC CBT method and the low spatter all-digital CO2 welding machine using BB technology. The GLC353CP welder from Cruises of Germany and the DL350 digital inverter MIG/MAG welder from OTC of Japan adopt the new AC short-circuit transition welding method, which is the welding power source at the positive (EP) and negative (EN) The polarity of the output is switched between the welding methods. According to reports, compared with the traditional inverter gas welding method, the amount of spatter adhesion is significantly reduced. According to OTC's introduction, the use of φ1.2 welding wire 250A CO2 gas protection welding, the traditional inverter CO2 gas welding spatter production is 2.4g/min, while the use of AC CBT method of CO2 gas welding spatter production is only 1.2g /min, the amount of splashing is reduced by a factor of two.

4 Short-circuit transition technology under precise control

Miller Corporation's RMD welding is a kind of precise control of short-circuit transition technology. By detecting the time of short-circuit current and controlling the welding current and welding voltage in time, the molten pool can be accurately controlled. It is a dynamic control technology. Root welds using RMD technology not only fuse well, but also fill gaps. In addition, the optimization of welding spatter, heat affected zone and smooth transition are all significantly stronger than those of traditional cellulose electrode root welding. The welding performance is excellent and all the processes of pipeline welding can be realized, which is very suitable for construction work in the field environment.

5. Multi-wire welding technology is everywhere

In recent years, multi-wire submerged arc welding of double wire, three wire, four wire, five wire, etc. has frequently appeared and has been used in many industries.

At the exhibition, multi-wire submerged arc welding technology exhibited by LINCOLN uses 1000A AC/DC inverter arc welding power supply and digital cooperative control technology. The first welding wire is powered by two 1000A AC/DC inverter arc welding power sources in parallel. The rest of the welding wire is powered by a 1000A class AC/DC power supply, which is mainly used for high-speed welding of thick-walled pipelines. According to reports, double-wire welding increases the welding speed by 30% compared with monofilament welding, and increases the input heat energy by 23%. The four-wire welding increases the welding speed and the production volume by 35% and improves the welding speed from 1.7m/min to three wires. 2.3m/min.

ESAB's four-wire and six-wire submerged-arc welding technology uses 1200A class SCR DC arc welding power sources, and each adopts one (a torch/billet) double wire, two four-wire and three six-wire wires. For multi-wire submerged arc welding, each double wire is powered by a 1200A power supply, and its production efficiency is high. According to reports, the amount of deposited metal increased from 12kg/h to 38kg/h for four wires (2*2*¢2.5) and monofilaments (1*¢4).

One to two, one to four, quick replacement of welding methods, increase productivity

Another technique to increase production efficiency is to use a multi-function arc welding power source with 2-4 wire feeding systems and their control drive units. According to the different requirements of welding materials and welding methods, a corresponding wire feeding system and control unit are selected, and the required welding state is quickly entered, and the auxiliary time is greatly reduced.

Cruze's double wire gas-shielded welding system is also very popular in China.

6. The welder's welding process performance has become the focus of the new welding technology industry competition

From the exhibition, we can see that the high-end products of the inverter welding machine are still dominated by foreign products. Any important new technology and new method (such as STT, CMT, Cold Arc, etc.) are all related to the welding process. This shows that the technical competition focus of inverter welding products has begun to shift from power supply technology and control technology to welding process performance.

For the domestic welding machine industry, whether or not this transfer can be achieved is a new and more severe challenge, because it is not easy to achieve technological breakthrough in the welding process than the process of breaking through the bottleneck of inverter welding power supply technology. This is a new challenge that we have to face. Perhaps it will determine the success or failure of a company in a new round of competition.

7 The use of automated welding systems has increased dramatically

Welding automation is to achieve high-efficiency, high-quality, and low-cost mass scale of the workpieces to be welded by means of advanced integration of welding processes, materials, equipment, automation control systems, welding fixtures, fixture positioning, and motion systems. Production to ensure stable, consistent batch production of high-quality products. Welding automation mainly includes welding automation planes and welding robots.

Nearly half of the exhibits on the show are special planes, most of which are equipped with robots. From the show, in the field of welding, the robot with the highest degree of automation is the industrial robot. The use of industrial robots in Europe, America and other countries has become very widespread. Large-scale application of industrial robots to meet the automation, flexibility and multi-functionality of complete sets of equipment is the future development trend.

Most of the domestic welding machines belong to the combination of welding auxiliary machines and welding power sources and wire feeders.

The exhibition shows the most prominent in welding automation technology and equipment: laser and its compound welding robots; arc welding robots; spot welding robots, special servo spot welding guns; various weld seam tracking technologies necessary for automatic welding and intelligent welding.

7.1 Laser Welding Robot Ensures Flexible Welding

Compared with traditional welding methods, laser welding has the advantages of energy concentration, small welding distortion, high welding speed, and good accessibility. It can be said that the combination of robots and laser welding is a perfect combination of high efficiency and high flexibility.

7.2 The application prospect of electric servo spot welding clamp is good

At present, most of the welding torches used in spot welding industry are pneumatic welding torches. The technical characteristics of the pneumatic welding torch and the technical requirements of the resistance spot welding determine that the electrode force is fixed and not adjustable in the welding process, and the response time is long. Therefore, it is difficult for the pneumatic welding torch to control the quality of the welding spot by changing the electrode force in a short time. However, the electric servo spot welding gun applies welding pressure by driving the electrode feed through the AC servo motor, and each parameter can be precisely controlled. At the same time, after the servo welding torch is applied in the spot welding industry, due to the change of the electrode pressure and the short response time, it can meet the response requirements of instantaneous forging pressure in resistance spot welding. As a result, the demand for galvanized steel sheets, aluminum alloys and ultrahigh-strength steels currently used in the automotive industry is increasing, and the electrode force controllable characteristics of the servo welding clamp are used, and in combination with other technical characteristics, the welding parameters are optimized for achieving this. The welding and quality control of difficult-to-weld materials opens up a good prospect for application.

At the exhibition, the number of spot welding robots increased significantly. German robot manufacturers such as NIMAK exhibited robots equipped with electric servo spot welding clamps.

7.3 Development of the Welding Automation Plan to Standardized Modularity

Special automatic welding equipment is a welding equipment specially designed for users. Its manufacturing difficulties are due to the user's personalized design, manufacturing, commissioning, and service, leading to long product delivery cycles, high risks, and high technical service costs. However, in recent years, with the rapid development of our country's modern manufacturing industry and the continuous improvement of our technology, the long delivery period and the urgent needs of users have become the prominent contradiction in the development of automated welding equipment. Through the exhibition, welding automation technology manufacturers and many other welding automation manufacturers gradually realized the importance of modular design, and actively carried out modular design and production management of automated welding equipment, and made considerable progress. This shows that modularization is the direction of development for automated welding machines.

From the exhibitions over the years, the proportion of welding automation equipment exhibits has increased year by year, and the level of its manufacturing process and the level of electronic control systems have greatly increased.

8 Research on basic parts such as automatic welding trolleys, wire feeders and welding guns

For a long time, CO2 MIG wire feeders and automatic welding trolleys have been recognized by the welders as auxiliary machines for welding machines and have not received much attention from the welding industry. In fact, this type of product is an indispensable part of the welding power supply, representing the depth of application and automation of CO2 MIG welding and submerged arc welding machines. A good welding power source provides the welding energy and the driver, and the welder pursues the quality of the weld, the welding effect and the welding efficiency, which are then synthesized by the wire feeder or the automatic car-joint welding torch, and are composed of the welding power source. The complete welding system can be reflected. Therefore, the quality difference and reliability of these auxiliary machines directly restrict the exertion of main power welding efficiency. With the popularization and improvement of welding automation, as well as the attention and pursuit of welding efficiency, the position and role of wire feeders and automatic welding trolleys have become more prominent and more and more attention has been paid by people in the industry.

9. Reasonable industrial structure and technological innovation are gradually forming

From the exhibition point of view, many mature technologies in foreign countries have only just started in China. There is a big gap between domestic and foreign welding technologies. The development course of advanced technologies can play a sufficient reference role for the development direction of domestic welding technology.

But no matter what, the collective appearance of the Chinese brand welder at the Essen show undoubtedly shows to the world that the Chinese welder is ready to march into the European market. The industry is not about size, the key lies in vitality, to achieve new development, and enhance enterprise technology research and development capabilities. Shanghai Hugong, Nantong Sanjiu, Shenzhen Ruiling, Christie Science and many other general-purpose product manufacturers have fully utilized the technology and brand advantages of the old companies, and have played a world in the international market; Kunshan Huaheng has actively advanced into robotic R&D. Tangshan Kaiyuan Robot System Co., Ltd. developed strongly from the establishment of Tangshan Kaiyuan Automatic Welding Equipment Co., Ltd.; Shanda Aotai, Nantong Zhenkang, Chengdu Kumagai, and Beijing Times focused on the research and development of general-purpose products; Beijing Zhongdian Huaqiang and Weld Research Weida, Weld Technology, Guangzhou Songxing, Wuxi Weihua, etc. increase investment in the development of special and complete sets of equipment, and the products continue to innovate; Shanghai GM, Shanghai Dongsheng, Chengdu Huayuan, and Shanghai Warwick scale and fine management The large-scale development of Yangtong Group and Hualian Group; Hangzhou Kelda not only pays attention to technical investment, but also vigorously develops the CNC cutting machine business, etc. One company with distinct characteristics has outlined the adjustment of the welding equipment industry to adjust the product structure. The research and development of new products and new technologies is a great development for the company.

10 Planning, Ideas, Awareness

Without exception, the world-famous welding equipment manufacturers have both long-term professional planning and focus on implementation. For example, ESAB has devoted decades of research to submerged arc welding; KEMPPI has been producing electricity since 1946, and so far. Still focused on inverter power research, has created multiple world firsts.

Through extensive contact with domestic and foreign welding machine manufacturers, the impression is very profound: well-known foreign companies have their own core technologies and their proprietary technical terms (such as we know STT, CMT, Power Wave, etc.), there are many new Or technical terms we haven't looked at before (such as Force Arc, etc.), and all have the R logo. This shows that foreign companies have a strong sense of core technology and intellectual property protection.

In short, in the three major exhibitions mentioned above, the image of companies from all over the world is distinctive. Colorful new products, new technologies, and new technologies have opened up the eyes of visitors and reflect the future development of the industry. In particular, companies in developed countries such as Europe and the United States have conducted in-depth and systematic research on welding technology, from complete sets of equipment to single welding machines, from welding materials to welding aids, etc.. The products not only excel in appearance, color coordination, stable performance, and good reliability. And the technical characteristics are very clear, these are worth learning and learning from our company.

It can be said that the above exhibitions have provided a showcase for welding equipment and technology at home and abroad, and also pushed the domestic and foreign welding equipment and technology advancement to a brand-new stage, pointing the way for the development of welding equipment and technology in China. We believe that China's welding technology will follow the objective laws and seek steady progress in the pursuit of facts. In the near future, we will surely join the world's leading ranks.