Development and Technological Progress of Metal Structure Industry

1 Basic overview of welding conditions in the metal structure industry

There are more than 90 enterprises and units under the metal structure Professional Committee of China Welding Association, which are dominated by heavy mining enterprises, oil and gas pipeline companies, chemical construction companies, metal truss structure companies, coal machinery enterprises and scientific research and development units.

Overview of Welding in 1.1 Heavy Ore Industry

The traditional products of enterprises in heavy mining industry, such as lifting equipment, excavation equipment, rolling and forging equipment, pressure vessels, large castings and forgings, aerospace launchers, oil film bearings, stacker and reclaimer, exhaust dozer, ship loading and unloading machine, dumper, rolling equipment, continuous casting equipment, steel barrel, ladle turntable, building materials products, etc. Enterprises in heavy mining industry grasp the two links of quality and cost and actively cooperate with foreign countries to learn new design concepts, actively promote new welding technologies, new materials and new processes, and promote efficient welding processes. It has successively cooperated with internationally renowned Demark Company, Krupp Company, Komatsu Production Institute and P & H Company to ensure product quality through the adoption of reasonable and advanced technology, which has been recognized by foreign investors. For example, it has produced a series of rolling mill equipment and lifting equipment for Baosteel's renovation project, including the largest 450t casting crane in China. 3100 m3/h compact bucket wheel excavator was produced for Zhungeer Coal Mine; P & H2300 and P & H2800 large electric shovels were produced for Dexing Copper Mine and Pingshuo Coal Mine.

Overview of Welding in 1.2 Petrochemical Industry

The oil and gas pipeline engineering industry is a specialized construction industry for long-distance oil and gas pipelines and large oil storage tanks. The main welding methods for pipeline construction are: cellulose electrode downward welding, low hydrogen electrode downward welding and flux-cored wire semi-automatic downward welding; the main welding methods for storage tanks are: manual arc welding, submerged arc automatic welding (flat welding, flat angle welding and horizontal welding), gas electric vertical welding and flux-cored wire gas shielded all-position automatic welding. In recent years, enterprises in this industry have undertaken many national key projects, such as: Shaanxi-Beijing Gas Pipeline Project, Sultanate Oil Pipeline Company, Hong Kong-Beijing Gas Pipeline Project and Sejinglan Gas Pipeline Project.

The chemical engineering construction industry is an industry with engineering construction and comprehensive building installation construction in the petrochemical industry. It has long been engaged in chemical fertilizer, oil refining and petrochemical, chemical and fine chemicals, petrochemical raw material storage and transportation, gas storage and transportation, food, medicine, textiles, Engineering construction in the fields of energy, building materials, etc, in recent years, it has been involved in electric power, metallurgy, light industry, transportation, environmental protection, civil construction, long-distance natural gas pipelines, bridges and other construction fields. The project covers all over the world, and the characteristics of its engineering welding structure are mainly the working environment of high pressure resistance, dynamic load resistance, corrosion resistance, high temperature and low temperature resistance.

Overview of Welding 1.3 Other Industries

Metal structure manufacturing enterprises use welding as the main processing method and are large-scale steel structure processing professional enterprises. Such enterprises mainly undertake the steel structure processing of industrial plants, commercial office buildings, civil residences and large-span public facilities, including: various large-scale profile structures, plate assembly structures, grid structures, pipes, cement tanks, trailer frames, hanging cranes, oil tanks and other series of steel structures and hardware welding manufacturing. So far, the completed projects include: steel structure of Shenzhen Diwang Commercial Building, steel structure of Shenzhen Citizen Center Building, bridge of Shenzhen China Merchants Bureau, Xiamen Kyushu Building, Hong Kong Cheung Kong Industrial Center Building, steel structure of Northeast Tower of Hong Kong Railway Station, etc.

Container manufacturing enterprises are also welding as the main processing means, specializing in the production of various types of containers. The container belongs to the all-welded structure, and the workshop is an assembly line production from blanking, forming, assembling, welding to post-processing painting.

In short, in the middle and late 1990 s, the leading enterprises in the metal structure industry realized the mechanization and automation of welding basic production methods through internal mechanism reform, technological transformation and scientific and technological investment, and developed products with the world's advanced level. Have the ability to manufacture international welding level equipment.

2 Metal structure industry welding technology progress achievements

Progress Achievements of Welding Technology in 2.1 Heavy Ore Industry

Enterprises in the heavy mining industry aim at the market development prospects, improve the added value of product technology, and develop coal deep processing products, high-speed train train wheel shafts, large keyless oil film bearings and other high-tech products. From 1999 to mid -2000, Taiyuan Heavy Machinery Group Co., Ltd. won the four world's most important products with high technical content and difficult manufacturing, namely: Ningbo Julong Piercing Unit, Three Gorges 1200t Bridge Crane, Liaoyuan 7500t Horizontal Extruder and the rotating stage of Shenzhen Century Window. Aiming at the market development trend, the technicians of Dalian Heavy Industry Group Co., Ltd. cooperated with the Welding Institute of the Construction Research Institute of the Ministry of Metallurgy in Beijing to jointly develop and develop the spray welding technology for the surface of large-scale rolls, and provided Angang with batch repair products, forming an annual output of 600 The production capacity of the company has formed a trend of sustainable development. The technicians of China First Tractor Construction Machinery Company have developed a computer-controlled tractor, a double-head CO2 gas shielded automatic welding special machine for variable gear shaft and a double-head CO2 gas shielded automatic welding special machine for tractor roller wheel, and applied the virtual technology in generator testing.

Enterprises in the heavy mining industry focus on the two links of product quality and efficiency, and vigorously promote new technologies and new processes.

The promotion and application of new fuel flame cutting technology. ② Promotion and application of high alloy composite strengthening welding technology. ③ Research and application of quantitative simulation of box girder welding deformation. ④ Study on flame spray welding technology on the surface of thick-walled conveying roller table. ⑤ Arc welding robot application research. Research on automatic tracking high-speed submerged arc welding process. ⑦ Special welding plane. The application of virtual technology in generator testing. The promotion and application of energy-saving, high-efficiency and consumption-reducing welding technology, such as friction welding and electron beam welding.

Progress Achievements of Welding Technology in 2.2 Petrochemical Industry

Oil and gas pipeline construction enterprises combined with industry development, vigorously promote the following new technologies and new processes.

Low hydrogen welding rod downward welding technology: applied in Shaanxi-Beijing gas pipeline project.

STT semi-automatic welding technology: STT semi-automatic welding equipment was introduced from Lincoln Company in the United States. On the basis of a large number of tests, the technology was applied to the welding of large-diameter long-distance pipelines. In the Sultanate oil pipeline project, more than 20000 welding Ф of 711mm root welding pass were welded.

③ All-position automatic welding technology of solid wire gas shielded welding: Through the introduction and absorption of this technology, it has been successfully applied to the Hong Kong-Beijing gas pipeline project and the Seining-Lan gas pipeline project (X70 test section).

The flux cored wire gas shielded welding all position automatic welding technology: the introduction and absorption of this technology, and in large storage tank welding application.

Chemical engineering construction enterprises combined with industry development, vigorously promote the following new technologies and new processes.

① Popularization and application of new welding technologies: including automatic welding technology for spherical tanks, circular submerged arc welding technology for storage tanks, hydraulic lifting and flip process for cylindrical storage tanks with automatic welding technology, double-sided synchronous argon arc welding technology for aluminum and stainless steel equipment, downward welding technology for long-distance pipelines, hot-melt butt welding technology for natural gas PE pipes, welding technology for stainless steel thin-walled pipes and brazing technology for copper pipes.

Application of new installation process methods.

③Heat treatment technology: In the heat treatment of large-scale equipment and spherical tank welds, we have successfully developed and applied the post-weld heat treatment technology of fuel oil method, gas method and electric heating method, and obtained the national construction method.

Achievements in welding technology progress in other industries in 2.3

Container specialized production enterprises, production organization form for assembly line operations, the main new welding technology is the application of high-speed welding and corrugated plate profiling welding.

3 Adjustment of product structure, development of new products and development direction of metal structure industry

Metal structure industry enterprises, on the one hand, with the change of market concept, users in addition to the functional, economic, practical and advanced requirements of the equipment, but also increased the requirements of environmental protection and energy saving and consumption reduction; on the other hand, with the change of national investment direction, metal structure industry enterprises are also changing product types. In order to meet the needs of the market and meet the requirements of clean production, enterprises have increased the intensity of technological innovation and technological development, and developed a series of environmentally friendly products and high-tech value-added products to meet the requirements of sustainable development strategies.

In short, the adjustment of the product structure of enterprises in the metal structure industry, the development of new products and the determination of the direction of development are mainly determined according to the direction of national investment and market demand.