In the 1960s and 1970s, the plates used for pipeline pipes were mainly A3 and 16Mn produced by Angang and other manufacturers. As the diameter of the pipeline increased and the transmission pressure improved, the strength of the steel plates could not meet the demand. After the 1980s, various petroleum welded pipe factories began to use pipeline steel plates produced according to American API standards. Due to the immature technology of domestic pipeline plate manufacturers at that time, they mainly used imported plates. After entering the 1990s, domestic pipeline plate production developed rapidly. Baosteel, Wuhan Iron and Steel, Anshan Iron and Steel, Benxi Iron and Steel, Panzhihua Iron and Steel and other enterprises have successively developed and produced high-grade X series pipeline steel.
The domestic pipeline steel production processes mainly include: conventional semi-continuous hot rolling, CSP continuous casting and rolling, medium and heavy plate units, and steckel coil units.
1) Semi-continuous rolling mill: including 1-stand steckel rolling mill and 5-stand finishing mill. On a semi-continuous rolling mill, the hot rolling that the strip undergoes in the finishing pass is essentially constant from one end of the strip to the other. The time between passes on the finishing mill is usually less than 3 seconds.
2) CSP continuous casting and rolling: In the CSP production line, the low carbon manganese steel containing niobium, vanadium and titanium composite micro-alloying can be guaranteed by using appropriate controlled rolling, cooling and coiling processes. The mechanical properties and microstructure of the steel meet the technical requirements of modern X60 pipeline steel and are in line with the development trend of modern pipeline steel. my country's CSP continuous casting and rolling production lines have developed X60 pipeline steel, while other CSP manufacturers in the United States and abroad have developed and produced high-grade pipeline steel X60, X65 and even X70. The characteristic of the process is that there is central segregation in the continuous casting thin slab. Eliminating the central segregation in the continuous casting thin slab is a key technical issue to further improve the quality of pipeline steel.
3) Medium and thick plate unit:
Mainly produces wide and thick plates for the production of straight seam submerged arc welded pipes. The straight seam submerged arc welded pipes are of reliable quality and are widely used in high-pressure oil and gas transportation. On the main line.
4) Steckel rolling mill
The Steckel rolling mill includes a reciprocating rough rolling mill and a 4-high reciprocating finishing mill. Two hot coil mills are installed on the conveyor lines on both sides of the finishing mill. The delivery roller table usually includes a laminar cooling system and a take-up station. In the steckel rolling mill, the thermomechanical history of the steel strip changes significantly along the entire length, especially in the production of microalloyed steel, which will strongly affect the degree of recrystallization, grain growth and precipitation produced in the finishing mill, and lead to the entire Drastic changes in ultimate microstructure and properties along the length of the strip. Its process is characterized by relatively low investment cost.
Foreign countries have produced X70 and The 1219mm diameter and 12.0mm wall thickness pipeline steel has been industrially produced. With the advancement of domestic metallurgical technology and equipment, the number of companies in my country that can produce pipeline steel coils has gradually increased. However, the only steel plants that can produce X70 and above grades are Baosteel, Wuhan Iron and Steel, Anshan Iron and Steel, Wugang, Nanjing Iron and Steel, Taiyuan Iron and Steel, etc. In addition, Baosteel, Wuhan Iron and Steel Company, Nanjing Iron and Steel Company, Anshan Iron and Steel Company and Wuyang Iron and Steel Company have also trial-produced X80 hot-rolled steel plates, and have trial-produced straight seam submerged arc welded pipes (JCOE) at Julong Steel Pipe Company. In the past two years, Nanjing Iron and Steel Co., Ltd. has increased its research and development of pipeline steel. X100 grade steel plates are under development. Anshan Iron and Steel Co., Ltd.'s X100 grade steel plates have passed the acceptance of relevant units.
1) my country’s domestic pipeline steel production output in recent years is shown in Table 1.
Domestic pipeline steel production mainly relies on hot rolling mills. The production of steckel mills is increasing, and the production of medium plate mills is less.
2) Basic situation of major domestic pipeline steel manufacturers
Baosteel: Baosteel’s development and production of pipeline steel has developed rapidly, and it has the absolute upper hand in the domestic market in terms of quantity and variety and quality. . In 1997, Baosteel produced 220,000 tons of pipeline steel, accounting for 88% of domestic consumption; in 1998, the output was 265,000 tons, with a domestic market share of 83%; in 1999, Baosteel produced 180,000 tons of pipeline steel, with a domestic market share of 65%. %. In 2000, Baosteel's pipeline steel production and sales increased significantly, with annual sales reaching 355,000 tons. After more than ten years of development and production of pipeline steel, Baosteel has mastered key technologies such as microalloying composition design, metallurgical process control, and production quality assurance of high-strength and high-toughness pipeline steel coils. Through continuous optimization and adjustment, the composition, process system and production quality control technology of Baosteel's X52, X65 and X70 series pipeline steels have been gradually formed, realizing product upgrading.
The products meet the needs of domestic and foreign markets and have stable quality. They have been successfully used in a series of major long-distance pipeline projects at home and abroad, such as my country's West-East Gas Pipeline Project, India Oil Pipeline, and Turkey Gas Pipeline. From August 2001 to May 2002, Baosteel has provided 150,000 tons of 14.6mm thick acicular ferrite In the West-East Gas Pipeline Project. In August 2005, Baosteel began to provide 70,000 tons of pipeline steel for the 26.2km submarine pipeline installed in the Panyu-Huizhou natural gas development project in Guangdong, which was designed, manufactured and constructed by itself in China. This is the first project in which Baosteel participates in submarine pipeline construction. The Guangdong Panyu-Huizhou natural gas development project is a national key project. It is the deepest and longest-spaced gas transmission pipeline in domestic submarine waters. The project's designed annual natural gas output is about 1.6 billion cubic meters, and the total length of the submarine pipeline is about 364km.
Baosteel’s 5000mm wide and thick plate project’s equipment and equipment from smelting, refining, continuous casting to rolling mills have reached the world’s advanced level. It was completed in 2005. The steel grade of the pipeline steel products is X80 (X100 is reserved). The maximum thickness is 40mm and the maximum width is 4500mm.
Wugang: It is the second largest pipeline steel manufacturer in China. In recent years, Wuhan Iron and Steel Co., Ltd. has regarded pipeline steel as its key development product, and its domestic market share has increased rapidly. In 1997, Wuhan Iron and Steel's pipeline steel output was only 2,800 tons, with a market share of only 1%. However, in 1999, Wuhan Iron and Steel's pipeline steel production increased to 63,000 tons, and it supplied 11 pipeline projects in the western market alone. Right, the domestic market share has increased to about 23%. Wuhan Iron and Steel has also made great progress in the quality of pipeline steel varieties. The high-toughness pipeline steel produced by Wuhan Iron and Steel Co., Ltd. has reached the physical level of similar steel products produced by major steel mills in Germany and Japan. In 2000, the development and production volume of WISCO's pipeline steel reached more than 160,000 tons. We have won bids for many major projects such as the Seninglan Pipeline, the Beijing-Yongqing Pipeline, the Iran Pipeline, the Iraq Pipeline, and the Daqing Oil Well Casing Pipeline. At the same time, the trial production of thick plate X65H and high-performance pipeline steel X70 has also been successful. User trials have shown that its performance indicators fully meet the technical requirements of the Seninglan Pipeline and Daqing Oil Well Water Injection Pipeline projects. In 2004, Wuhan Iron and Steel Co., Ltd. made a major breakthrough in the research and development of pipeline steel, successfully realizing large-scale and stable supply of 17.5mm thick X70 high-performance pipeline steel. It has successively undertaken the supply rights of more than 10 pipelines, including the Sudan Pipeline, the China-Kazakhstan Pipeline, the Shaanxi-Beijing Pipeline, the Yanjiang Pipeline, the Shuanglan Pipeline, and the Jining Pipeline. The annual contract volume reached more than 700,000 tons, ranking first in the country. Subsequently, we actively carried out research and testing of 15.3mm and 17.5mm high-strength and high-toughness X80 hot-rolled thick plate coils, and successfully passed the appraisal of China National Petroleum Corporation. Experts from the appraisal committee believe that the 15.3mm thick hot-rolled coils of X80 pipeline steel developed by Wuhan Iron and Steel Co., Ltd. can fully meet the requirements of X80 spiral welded pipes, have mass production stability, and can achieve mass production and supply as required.
Ansteel: In November 2002, the ASP line has provided more than 4,000 tons of X52 grade pipeline steel for the long-term gas pipeline project, and has developed and produced X70 and X80 high-grade pipeline steel plates and coils. , and can be produced industrially. On July 7, in my country's new "Sichuan Gas Out of Sichuan" large-scale natural gas pipeline test section exhibition project, Anshan Iron and Steel Group monopolized the right to supply 32,000 tons of extreme specification X70 pipeline steel coils for spiral welding. At the same time, Anshan Iron and Steel also undertook a production contract for 19,500tX70 straight seam welded pipeline steel. The "Sichuan Gas Out of Sichuan" natural gas pipeline project is an important gas transmission project in my country's "11th Five-Year Plan", with a total pipeline length of 1,937km. Anshan Iron and Steel Co., Ltd. is the only manufacturer in China that can produce and supply 30.4mm thick X70 wide and thick plates. On July 13 this year, the X100 pipeline steel wide and thick plates produced by Anshan Iron and Steel Co., Ltd. and the straight seam welded steel pipes rolled with them successfully passed the test evaluation of the China Petroleum Pipe Research Institute, an authoritative domestic scientific research institution.
The successful development of X100 pipeline steel has enabled Anshan Iron and Steel Pipeline Steel to form a series of X60, X65, X70, X80 and .
Benxi Iron and Steel: In the "Revitalization of Northeast Old Industrial Base High-tech Industry Project" organized and implemented by the state, the "Industrialization of High-Performance Pipeline Steel Production" jointly submitted by Benxi Iron and Steel and the Institute of Metal Research, Chinese Academy of Sciences passed After passing the review of the expert group, the project received national funding support of 10 million yuan. The implementation of the "Industrialization of High-Performance Pipeline Steel Production" project will make Benxi Iron and Steel become the only domestic steel enterprise capable of producing high value-added and high-grade X70 pipeline steel after Baosteel, Wuhan Iron and Steel, and Anshan Iron and Steel. Bengang's development of oil pipeline steel began in the late 1980s, and it was one of the earliest domestic steel companies to develop steel for oil pipelines.
After more than ten years of development, Benxi Iron and Steel has successively developed A, B, X42, X46, X52, X56, X60, X65 and X70 pipeline steels suitable for oil and natural gas transmission pipelines, forming The series of steel for oil and natural gas transmission pipelines has been established. In particular, after modernizing steelmaking and hot rolling in 2002, Benxi Iron and Steel has accelerated the research and development of high-performance pipeline steel, and has successively developed high-performance oil pipeline steel X52~X70 and oil casing steel that can meet user requirements. Pipe steel J55 participated in the sub-topic "Industrial Basic Research on High-Strength Pipeline Steel" in the national "973" project "Major Basic Research on New Generation of Steel Materials". So far, oil pipeline steel X52~X70 has passed the performance evaluation of coils and steel pipes by the China National Petroleum Pipe Materials Institute and the Pipeline Bureau, and the physical quality meets the national West-East Gas Transmission’s special quality technical requirements for pipeline steel. Its products have been used in many gas, oil and refined oil pipeline projects. In the past two years, Bengang has produced more than 90,000 tons of oil pipeline steel. The products have been produced and used by many pipe factories such as Huayou Steel Pipe Co., Ltd. and Baoji Petroleum Steel Pipe Factory. The product quality fully meets the technical requirements of the special standards of users. , X80 pipeline steel will also pass the appraisal and acceptance in the second half of 2006.
Hangan Iron and Steel: In 2000, X52 and X60 pipeline steel with a thickness of 7.9mm were developed on CSP units and put into mass production.
Maanshan Iron and Steel: From January 2006 to December 2007, it will develop and commercially produce niobium microalloyed X52~X56 pipeline steel in the CSP production line (due to the limitation of the shearing capacity of the sampling shears, The maximum thickness of Maanshan Iron and Steel CSP pipeline steel can only be produced to the commercial thickness of X56 grade); the traditional hot rolling production line in Maanshan Iron and Steel New District develops niobium micro-alloyed X70~X80 pipeline steel.
Nangang: On October 28, 2005, X60 pipeline steel and 9.5mm steel coils with a thickness of 8.7mm were successfully rolled out at the medium-thick plate coil plant. Industrial production of X70 pipeline steel has also begun. , X80 has been developed, but the production volume is not too large, with a maximum thickness of 40mm and a maximum width of 3300mm. X100 has been listed as a scientific research project and is being prepared for development.
Jigang: The medium plate factory and medium thick plate factory produced nearly 500t User demands have laid a solid foundation for the next development of higher-grade pipeline steel.
Anyang Iron and Steel: From January 2006 to December 2007, it cooperated with the Iron and Steel Research Institute to develop and produce L245NB/L245MB, X42 L290NB/L290MB, X46, X52 L360NB/ on its Steckel rolling mill L360MB, X56, X60 L415NB/L415MB, X65 L450MB, X70 L485MB,
TISCO: Taigang has the production process conditions for the production of X56, X60, and X65 high-grade pipeline steel, and the first batch of L360 pipeline steel produced was shipped to Baoji on September 29, 2001. After supervision by the Cangzi Gas Transmission Project Department and the first inspection by the Baoji Steel Pipe Factory, all indicators such as the mechanical properties of the base material and pipes were qualified. In the "Cangzhou-Zibo" gas transmission pipeline project, TISCO won the bid for more than 7,300 tons of L360 pipeline steel, which will be manufactured by Baoji Steel Pipe Factory.
Pangang: It has been able to mass produce six major varieties of pipeline steel from grade B to grade X65.