A novel hot rolled steel LG600A with the tensile strength exceeding 700 MPa was developed for automatic teller machine application. Thelow-cost C-Mn steel was microalloyed with：0.08 mass%- 0.12 mass% Ti rather than n...A novel hot rolled steel LG600A with the tensile strength exceeding 700 MPa was developed for automatic teller machine application. Thelow-cost C-Mn steel was microalloyed with：0.08 mass%- 0.12 mass% Ti rather than noble alloying elements, such as Nb, V, Mo, and Cu, etc. The novel steel had a good surface quality and welding property. After the hot rolled steel coils were leveled, the steel plates, the length of which was even down to 1 500 mm, had an excellent flatness. The effects of hot rolling parameters on mechanical per formance, m icrostructure and recrystallization behavior were studied. The metallurgical concept for the steel production was also discussed. The result shows that decreasing the finish rolling temperature, increasing cooling rate in the first cooling stage and decreasing the cooling rate in the last cooling stage, together with coiling at a modestly high coiling temperature all resulted in the refined grains and TiC precipitates, thereby improving the strength and toughness of this new steel greatly.展开更多
3 D roll-forming for high strength steel sheets is a new technology at present.Double racks gear 3D roll forming machine developed by our research group can be used to perform variable cross section roll forming for h...3 D roll-forming for high strength steel sheets is a new technology at present.Double racks gear 3D roll forming machine developed by our research group can be used to perform variable cross section roll forming for high strength steel.In the paper,a dynamic model of 8-DOF double rack gear 3D roll-forming machine is established by the method of Lagrange equation.The expression of the angle acceleration of the system response is obtained by solving the dynamic equations.Through an actual engineering example,the dynamical characters of the 3D roll forming machine are revealed.The results can support the design of 3D roll forming machine.Meanwhile,the research will play an active role in the development of control system.展开更多
文摘A novel hot rolled steel LG600A with the tensile strength exceeding 700 MPa was developed for automatic teller machine application. Thelow-cost C-Mn steel was microalloyed with：0.08 mass%- 0.12 mass% Ti rather than noble alloying elements, such as Nb, V, Mo, and Cu, etc. The novel steel had a good surface quality and welding property. After the hot rolled steel coils were leveled, the steel plates, the length of which was even down to 1 500 mm, had an excellent flatness. The effects of hot rolling parameters on mechanical per formance, m icrostructure and recrystallization behavior were studied. The metallurgical concept for the steel production was also discussed. The result shows that decreasing the finish rolling temperature, increasing cooling rate in the first cooling stage and decreasing the cooling rate in the last cooling stage, together with coiling at a modestly high coiling temperature all resulted in the refined grains and TiC precipitates, thereby improving the strength and toughness of this new steel greatly.
基金Supported by the National Science and Technology Supporting Plan Projects of China （No.2011BAG03B03）.
文摘3 D roll-forming for high strength steel sheets is a new technology at present.Double racks gear 3D roll forming machine developed by our research group can be used to perform variable cross section roll forming for high strength steel.In the paper,a dynamic model of 8-DOF double rack gear 3D roll-forming machine is established by the method of Lagrange equation.The expression of the angle acceleration of the system response is obtained by solving the dynamic equations.Through an actual engineering example,the dynamical characters of the 3D roll forming machine are revealed.The results can support the design of 3D roll forming machine.Meanwhile,the research will play an active role in the development of control system.
