China's steel production in 2005 reached 349 million tons, becoming the world's largest steel production and consumption, while the welding structure of steel consumption also exceeded 130 million tons, equivalent to the United States a year of steel production, becoming unprecedented in the world The largest manufacturer of welded steel.

 

    From 2005, China completed a number of landmark projects, welding technology has played an important role. For example, the hydropower equipment of the Three Gorges Project is a huge welding system, including aqueduct, volute, wheel, large shaft, generator frame, etc., of which the martensitic stainless steel wheel diameter of 10.7 m high 5.4 M  heavy 440 t, the world's largest cast - welded structure wheel. The runner is welded by the upper crown, the lower ring and 13 or 15 blades. The welding of each runner requires 12 t of wire, which takes four months. The successful launch and recovery of the Shenzhou 6 spacecraft marked the great progress of China's space industry. Two of the flight crew and track cabin were the welding structure of the aluminum alloy, and the airtightness and deformation control of the welded joint were The key to welding manufacturing. By the end of 2005 by the first heavy machinery group for the Shenhua company made China's first coal direct liquefaction device hydrogenation reactor, diameter 5.5 m  long 62 m  thick 337 mm  weight 2 060 t, for the world's largest , The most important forging-welding structure of hydrogenation reactor, the use of domestic independent intellectual property rights of the automatic double-wire narrow-gap submerged arc welding technology, each ring welds need to continue welding 5 days. The West-East Gas Pipeline is 4 000 km long and is the first high-strength steel (X70) long-distance pipeline in China. The spiral steel pipe and straight seam steel pipe are all welded pipe. In 2005, China's shipbuilding gross tonnage reached 12.2 million tons, accounting for 17% of the world's total shipbuilding, living in Japan, Korea, ranking third in the world, is an annual output of 25 million tons of the world level. Domestic manufacturing of 300,000 tons of super tankers, the new 5668 TEU container ships, 150,000 tons of bulk cargo ships, as well as the world's attention, known as the "China's first shield" of the 170 ships, are China's shipbuilding industry pride, hull Is a typical plate-welded structure. In addition, the Shanghai Lu Pu Bridge is the world's longest all-welded steel arch bridge; National Grand Theater's ellipsoidal dome is the world's most important steel dome; is the construction of the Olympic main stadium bird nest steel structure more than 40,000 tons , Is also the world's most These large structures are the largest, heaviest, longest, highest, thickest and most important representative products of China's welding. Thus, welding in the national economic development and national defense construction has a very important position and role.