On July 4 2002, a project attracting world attention, i.e., the West-East Gas Pipeline Project was declared in full-scale commencement. The project will write history with its enormous social and economic benefits.
In the research, problems and damages of soil erosions in West -East Natural Gas Transmission were analyzed; the reasons were summarized and the characteristics of soil erosion were researched in order to explore prin...In the research, problems and damages of soil erosions in West -East Natural Gas Transmission were analyzed; the reasons were summarized and the characteristics of soil erosion were researched in order to explore principles of pipeline prevention and seek countermeasures.展开更多
HTP practice,alloyed with low-carbon (less than 0.06%) and high-niobium (up to 0.11%),has been developed to produce large-wall X80 hot rolled strip for 2nd West-East Gas Pipeline project successfully.In this paper,exi...HTP practice,alloyed with low-carbon (less than 0.06%) and high-niobium (up to 0.11%),has been developed to produce large-wall X80 hot rolled strip for 2nd West-East Gas Pipeline project successfully.In this paper,existing status of niobium at different rolling stage,such as reheating,rough rolling and final product and strengthening effects have been presented and analyzed systematically.Some technological questions concerrned,such as the mixed grain occurred on the delay table,dynamic recrystallization during the finish rolling course,γ→αtransformation and final microstructure obtained at low coiling temperature,have been explored further.Analytical results presented increased recrystallization stop temperature due to high niobium contents can provide the requisite to remove waiting-temperature operation of transfer bar before finish rolling to ensure controlled effect of traditional low-temperature,which is benificial not only to production efficiency,but also to uniformity of austenite microstructure.Secondly,dynamic-recrystallization occurred during finish rolling may reduce the density of dislocation,but will better the grain gradient along the thickness because the dynamic recrystallization proceeds instantly,which is beneficial to reduce the appearance of separation of impact fracture.Finally,the lower coiling temperature than traditional TMCP practice,up to 300℃,is a key factor to obtain low-carbon bainite microstructure composed of acicular ferrite and small amount M/A component,which results in high strength and excellent low-temperature toughness.展开更多
With the increase in energy demand, the demand for oil and gas transmission pipes, particularly high-grade longitudinal submerged arc welded pipes （LSAWs）, have been growing in recent years. The construction of the ...With the increase in energy demand, the demand for oil and gas transmission pipes, particularly high-grade longitudinal submerged arc welded pipes （LSAWs）, have been growing in recent years. The construction of the 2nd West -East natural gas transmission pipeline project shows that the oil and gas pipeline construction has entered a new phase of development with X80 pipes being applied in large scales for the first time in China. This paper briefly introduces the 2nd West-East natural gas transmission pipeline project and its main technical requirements with the focus on the features of API standard 5L X80 grade Ф 1219 mm series of U-ing-O-ing-Expanding （ UOE ） LSAW pipes, which Baosteel developed with the integrated technology for the 2nd West-East natural gas transmission pipeline project. The analysis shows the extra-low carbon content, the high contents of manganese and niobium, the fine microstructure, the high strength,the toughness and the good weldability of X80 pipes meet the requirements of ＂the technical specification of LSAW linepipes for the 2nd West-East natural gas transmission pipeline project in China＂. By the end of June 2010, Baosteel had totally produced 322000 t of Ф 1219 mm X80 UOE steel pipes, which have been successfully used in the 2nd West-East natural gas transmission pipeline project, thus filling the gap of the production of large diameter X80 UOE LSAW pipes in China.展开更多
文摘On July 4 2002, a project attracting world attention, i.e., the West-East Gas Pipeline Project was declared in full-scale commencement. The project will write history with its enormous social and economic benefits.
基金Supported by Scientific Research Program of Water Resources Department of the Xinjiang Uygur Autonomous Region (xjsl-2011-11)Young Core Project of Northwest A&F University (KZCXI-10-4-1)~~
文摘In the research, problems and damages of soil erosions in West -East Natural Gas Transmission were analyzed; the reasons were summarized and the characteristics of soil erosion were researched in order to explore principles of pipeline prevention and seek countermeasures.
文摘HTP practice,alloyed with low-carbon (less than 0.06%) and high-niobium (up to 0.11%),has been developed to produce large-wall X80 hot rolled strip for 2nd West-East Gas Pipeline project successfully.In this paper,existing status of niobium at different rolling stage,such as reheating,rough rolling and final product and strengthening effects have been presented and analyzed systematically.Some technological questions concerrned,such as the mixed grain occurred on the delay table,dynamic recrystallization during the finish rolling course,γ→αtransformation and final microstructure obtained at low coiling temperature,have been explored further.Analytical results presented increased recrystallization stop temperature due to high niobium contents can provide the requisite to remove waiting-temperature operation of transfer bar before finish rolling to ensure controlled effect of traditional low-temperature,which is benificial not only to production efficiency,but also to uniformity of austenite microstructure.Secondly,dynamic-recrystallization occurred during finish rolling may reduce the density of dislocation,but will better the grain gradient along the thickness because the dynamic recrystallization proceeds instantly,which is beneficial to reduce the appearance of separation of impact fracture.Finally,the lower coiling temperature than traditional TMCP practice,up to 300℃,is a key factor to obtain low-carbon bainite microstructure composed of acicular ferrite and small amount M/A component,which results in high strength and excellent low-temperature toughness.
文摘With the increase in energy demand, the demand for oil and gas transmission pipes, particularly high-grade longitudinal submerged arc welded pipes （LSAWs）, have been growing in recent years. The construction of the 2nd West -East natural gas transmission pipeline project shows that the oil and gas pipeline construction has entered a new phase of development with X80 pipes being applied in large scales for the first time in China. This paper briefly introduces the 2nd West-East natural gas transmission pipeline project and its main technical requirements with the focus on the features of API standard 5L X80 grade Ф 1219 mm series of U-ing-O-ing-Expanding （ UOE ） LSAW pipes, which Baosteel developed with the integrated technology for the 2nd West-East natural gas transmission pipeline project. The analysis shows the extra-low carbon content, the high contents of manganese and niobium, the fine microstructure, the high strength,the toughness and the good weldability of X80 pipes meet the requirements of ＂the technical specification of LSAW linepipes for the 2nd West-East natural gas transmission pipeline project in China＂. By the end of June 2010, Baosteel had totally produced 322000 t of Ф 1219 mm X80 UOE steel pipes, which have been successfully used in the 2nd West-East natural gas transmission pipeline project, thus filling the gap of the production of large diameter X80 UOE LSAW pipes in China.
