1. The production process is different
Carbon steel pipes are made of steel ingots or solid round steel perforated into capillary tubes, which are then hot rolled, cold rolled or cold drawn. Carbon steel pipes play an important role in my country's steel pipe industry.
The method of manufacturing the clarinet (furnace welding or electric welding) is chosen by the manufacturer. Galvanizing adopts hot dip galvanizing method. Uniformity of galvanized layer Galvanized steel pipes should be tested for uniformity of galvanized layer. The steel pipe sample shall not turn red (copper-plated color) when immersed in copper sulfate solution for 5 consecutive times.
2. Different materials used
General carbon steel pipe: It is made of hot-rolled or cold-rolled high-quality carbon steel such as 10, 20, 30, 35, 45, 16Mn, 5MnV and other low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other alloy steel. Seamless pipes made of 10 and 20 grade low carbon steel are mainly used for fluid transportation pipelines.
Hot-dip galvanizing pipe reacts molten metal with an iron matrix to produce an alloy layer, thereby combining the matrix and the coating. Hot-dip galvanizing is to pickle the steel pipe first. In order to remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned in an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to in a hot dip plating tank.
3. Different technical parameters
Carbon steel pipes play an important role in my country's steel pipe industry. According to incomplete statistics, there are more than 240 carbon steel pipe manufacturers in my country, with more than 250 carbon steel pipe units, and an annual production capacity of about 4.5 million tons.
In terms of caliber, those <φ76 account for 35%, and those <φ159-650 account for 25%. In terms of varieties, general-purpose pipes accounted for 1.9 million tons, accounting for 54%; petroleum steel pipes accounted for 760,000 tons, accounting for 5.7%; hydraulic props and precision pipes accounted for 150,000 tons, accounting for 4.3%; stainless steel bearing pipes and automobile pipes totaled 50,000 tons. Accounting for 1.4%.
Galvanized steel pipes are divided into cold-dip galvanized steel pipes and hot-dip galvanized steel pipes. Cold-dip galvanized steel pipes have been banned, and the latter is also recommended by the country to be temporarily used. In the 1960s and 1970s, developed countries in the world began to develop new pipes and gradually banned galvanized pipes. China's Ministry of Construction and four other ministries and commissions have also issued documents clarifying that galvanized pipes will be banned as water supply pipes starting in 2000. Galvanized pipes are rarely used in cold water pipes in newly built communities, and hot water pipes in some communities use galvanized pipes.