As an important part of iron and steel products, steel pipe plays an essential role in the development of national economy. According to the different forming process, welding method and the used tube billet shape, steel pipe can be divided into the following kinds: large diameter seamless pipe, ERW steel pipe and spiral welded pipe. ERW steel pipe is divided into high frequency ERW steel pipe and large diameter LSAW steel pipe. At present, the general trend of the world steel industry is that the growth speed of
welded pipe production is faster than that of seamless tube production. Welded pipe production is far greater than seamless tube production in proportion. The seamless pipe market is contended in various fields. In welded tube’ types,
ERW welded pipe dominates in the production, and LSAW steel pipe market and SSAW steel pipe market are contended in the use fields of oil and gas long-distance pipeline and urban gas pipeline.
With the development of
seamless tube, welded pipe technology development is progressing. This is an inevitable trend that welded pipe will gradually replace seamless tube in some fields. The key factor lies in that products’ quality are constantly improved and the manufacturing cost is relatively low. Quality improvement of welded pipe products mainly relies on three aspects of technical progress: iron and steel smelting technology, hot rolled strip steel technology and steel pipe manufacturing process.
Western developed countries are focusing on expanding the use area of ERW welded pipes. America, representing North America countries, puts emphasis on exploiting ERW OCTG pipe application scope. ERW casing pipes have been widely used in the 3000m deep wells in the 1980s. Europe, representing Germany countries, focuses on developing boiler tube application scope. Low pressure boiler tube made by ERW welded tubes is also widely used, whose amount accounts for more than half of total amount of boiler tube. In addition, ERW welded pipes are also used for a part of high pressure boiler tube. Japan and South Korea, representing Asia countries, almost comprehensively develops the application range of ERW welded pipe. Welded pipe accounts for more than 98% of the total steel production, and ERW welded pipe accounts for more than 90% of total welded pipe production in South Korea. Due to the rapid progress of welded pipe production technology and the decrease of its cost, welded pipe gradually replaces a part of seamless tubes and UOE welded pipes in Japan.
It is an evitable trend that welded pipe will definitely replace seamless pipe. With the constant upgrading welded pipe production technology in various steel pipe manufacturing companies, welded pipe with more complete production lines and higher quality will be used in the future.
