Taking the seamless tube plant of Baoshan Iron & Steel Complex in China as the background,we analyze the characters of hot rolling seamless steel tube:multi varieties,low volume,complicated production process,flex...Taking the seamless tube plant of Baoshan Iron & Steel Complex in China as the background,we analyze the characters of hot rolling seamless steel tube:multi varieties,low volume,complicated production process,flexible production routes.Then integrated scheduling problem for hot rolling seamless steel tube production is studied,which covers two key points;order-grouping problem and solution method for flowshop/jobshop scheduling problem.On the basis of these two problems,integrated scheduling decision system is developed.The design idea,function flow sheet,data processing method,and functional module of visualized human-computer interactive scheduling system implemented in seamless steel tube plant of Shanghai Baoshan Iron & Steel Complex are described into detail.Compared with manual system,the performance of system shows the applicability and superiority in several criteria.展开更多
In this paper, we review the evolution of 12CrlMoV steel standards at home and abroad, analyze the effects of various elements and determine their optimal contents in steel. The influence of heat treatment and microst...In this paper, we review the evolution of 12CrlMoV steel standards at home and abroad, analyze the effects of various elements and determine their optimal contents in steel. The influence of heat treatment and microstructure on the creep strength of 12CrlMoV steel is investigated. Statistical results from conventional mechanical properties, ductile-brittle transition temperature, high temperature oxidation resistance, aging, instant high temperature properties, and creep are introduced. The results show that the chemical composition and heat treatment process of 12CrlMoVG steel identified in the GB 5310 - 2008 standard is appropriate, resulting in a steel with higher creep strength and good comprehensive properties.展开更多
A 25CrMo48V steel for ultra-deep oil/gas well casings was quenched at 900-1 200 ℃ and tempered at 650 ℃. The lath martensitic structures were characterized by optical microscope （OM）, field emission scanning elect...A 25CrMo48V steel for ultra-deep oil/gas well casings was quenched at 900-1 200 ℃ and tempered at 650 ℃. The lath martensitic structures were characterized by optical microscope （OM）, field emission scanning electron microscopy （FESEM）, electron backscattering diffraction （EBSD） and transmission electron microscopy （TEM）, and the transverse impact energy at 0 ℃ was measured from the as-quenched and tempered specimens. The results show that with the quenching temperature decreased, the prior austenite grain, martensitic packet and block are refined, while the lath width seems to remain unchanged. The enhancement of impact toughness with the decreasing quenching temperature can be attributed to refinement of the martensitic structure with high-angle boundaries, and the block is the minimum structure unit controlling impact toughness. The transverse impact energy [ECVN （0 ℃） ≥100 J] required for seamless casings with ultra-high strength （Rp0.2≥932 MPa） has been finally achieved with the experimental steel quenched at 900-1 000 ℃ and tempered at 650 ℃.展开更多
The relationship between microstructures and mechanical properties of a medium carbon V-N microalloyed steel used for N80 seamless oil-well tubes of hot rolling non-quenched/tempered (non-Q and T) was investigated.The...The relationship between microstructures and mechanical properties of a medium carbon V-N microalloyed steel used for N80 seamless oil-well tubes of hot rolling non-quenched/tempered (non-Q and T) was investigated.The results have shown that volume percentages of upper bainite,modified bainite and ferrite have a decisive influence on impact energies of steel tubes.When the total volume percentage of bainite is larger than 5%,the impact energy of tubes can not satisfy with the industrial criteria.Moreover,if the total volume percentage of bainite is smaller than 5%,then the impact energy of steel tubes enhances with volume percentage of ferrite increasing.The final microstructures have closely relation with tube billet quality,controlled cooling temperature after tube rolling and cooling method after stretch-reduction-diameter.High quality of medium carbon V-N microalloyed steel for non-Q and T oil-well tubes can be produced through comprehensive control of microstructures and mechanical properties in sub-procedures,especially for tube billet quality and controlled cooling parameters.展开更多
文摘Taking the seamless tube plant of Baoshan Iron & Steel Complex in China as the background,we analyze the characters of hot rolling seamless steel tube:multi varieties,low volume,complicated production process,flexible production routes.Then integrated scheduling problem for hot rolling seamless steel tube production is studied,which covers two key points;order-grouping problem and solution method for flowshop/jobshop scheduling problem.On the basis of these two problems,integrated scheduling decision system is developed.The design idea,function flow sheet,data processing method,and functional module of visualized human-computer interactive scheduling system implemented in seamless steel tube plant of Shanghai Baoshan Iron & Steel Complex are described into detail.Compared with manual system,the performance of system shows the applicability and superiority in several criteria.
文摘In this paper, we review the evolution of 12CrlMoV steel standards at home and abroad, analyze the effects of various elements and determine their optimal contents in steel. The influence of heat treatment and microstructure on the creep strength of 12CrlMoV steel is investigated. Statistical results from conventional mechanical properties, ductile-brittle transition temperature, high temperature oxidation resistance, aging, instant high temperature properties, and creep are introduced. The results show that the chemical composition and heat treatment process of 12CrlMoVG steel identified in the GB 5310 - 2008 standard is appropriate, resulting in a steel with higher creep strength and good comprehensive properties.
基金Item Sponsored by National High Technology Research and Development Program of China(2007AA03Z509)National Science Foundation for Distinguished Young Scholars of China(50925522)
文摘A 25CrMo48V steel for ultra-deep oil/gas well casings was quenched at 900-1 200 ℃ and tempered at 650 ℃. The lath martensitic structures were characterized by optical microscope （OM）, field emission scanning electron microscopy （FESEM）, electron backscattering diffraction （EBSD） and transmission electron microscopy （TEM）, and the transverse impact energy at 0 ℃ was measured from the as-quenched and tempered specimens. The results show that with the quenching temperature decreased, the prior austenite grain, martensitic packet and block are refined, while the lath width seems to remain unchanged. The enhancement of impact toughness with the decreasing quenching temperature can be attributed to refinement of the martensitic structure with high-angle boundaries, and the block is the minimum structure unit controlling impact toughness. The transverse impact energy [ECVN （0 ℃） ≥100 J] required for seamless casings with ultra-high strength （Rp0.2≥932 MPa） has been finally achieved with the experimental steel quenched at 900-1 000 ℃ and tempered at 650 ℃.
基金financial support from Chinese National Nature Science Fund(Project No.50271009and No.51071019)Wuxi Seamless Steel Tube Company,Ltdthe Vanadium International Technical Committee via the CSM
文摘The relationship between microstructures and mechanical properties of a medium carbon V-N microalloyed steel used for N80 seamless oil-well tubes of hot rolling non-quenched/tempered (non-Q and T) was investigated.The results have shown that volume percentages of upper bainite,modified bainite and ferrite have a decisive influence on impact energies of steel tubes.When the total volume percentage of bainite is larger than 5%,the impact energy of tubes can not satisfy with the industrial criteria.Moreover,if the total volume percentage of bainite is smaller than 5%,then the impact energy of steel tubes enhances with volume percentage of ferrite increasing.The final microstructures have closely relation with tube billet quality,controlled cooling temperature after tube rolling and cooling method after stretch-reduction-diameter.High quality of medium carbon V-N microalloyed steel for non-Q and T oil-well tubes can be produced through comprehensive control of microstructures and mechanical properties in sub-procedures,especially for tube billet quality and controlled cooling parameters.
