The production and use of steel pipes has a history of more than 100 years. In the early 19th century, due to the needs of war, people used steel plates to bend into tubes, then heated the lapped edges, and forged tubes on short mandrels to make gun barrels. With a great development, the furnace welded steel pipe method appeared around 1825. This method is to heat the metal strip to the welding temperature and pull it out of the bowl mold. Since then, the welded pipe has begun to be produced on an industrial scale.
After 1843, the production of seamless pipes has developed greatly. By 1896, various technologies and equipment for the production of seamless pipes appeared one after another, making the production of seamless pipes from basic theory, production technology to various auxiliary equipment. A relatively complete system has been established. At the beginning of the twentieth century, the resistance welding technology using the Hall effect began to be used in the production of welded pipes. Jost et al. for the resistance welding welding temperature, welding pressure, welding speed and their relationship, as well as the metallographic structure and mechanical properties of the weld. Influence, etc., have been carefully studied.
At the same time, a series of studies have been carried out on other forming and welding process issues, so that the quality of the welded pipe has been significantly improved. In the 1930s, the production of electric welded pipes has achieved widespread development. After 1960, there have been many major improvements and innovations in the forming technology, quality control and inspection technology, and finishing equipment of medium and small diameter electric welded pipes.
The main reasons for the huge development of high frequency straight seam welded pipes in the past three decades are:
1. Low cost and less investment in building a factory
2. Significant improvement in weld quality
3 Widespread use of non-destructive testing techniques
4 Expansion of the range of varieties and specifications