Connected By Pairs Of Metal Rolling Parameters Studied Research

Complex of materials, especially complex of different kind of metals, have provided a new approach for developing the new merits of material. The rolling process is efficient and economical to other types of processes, such as explosive cladding, diffusion welding, etc. The rolling processes have developed from hot-roll bonding technique to cold-roll bonding technique and asynchronous roll bonding technique. Because of the complexity of rolling at the roll gap, the theory research of rolling processes is in exploring stage. In this text, the bonding mechanism of bimetal is attempted to inquire into and carry on theoretical analysis to bonding, and find out the reasonable rolling condition.At first, the mechanism of bimetal roll-bonding about the plastic deformation has been analyzed in this text, and assumes that the point of the bonding of interface occur when both of upper and lower at interface metals take place of the plastic deformation. Then, with mean shear yield stresses of the metal is the criterion , using the slab method, the model has derived out the mathematical expressions, such as the bonding point ,the neutral points and the thickness ratio of upper layer to the sandwich sheets after rolling. By way of the change rolling condition parameters, has found out the relation between the bonding rate and the thickness ratio of upper layer to the sandwich sheets after rolling.Second, using large-scale finite element method software—MARC establishes the rolling model, and compiles the process file, and sets up the different rolling condition parameters. I carried on simulation under the different conditions, such as reduction of rolling ratio, different metals, changing of rolling speed, frictional factors of the roller and layer, and so on. We can gain the bonding rate and the thickness ratio of upper layer to the sandwich sheets after rolling, and conclude the close conclusion with the analysis of the slab method. At the meantime, using the MARC software can directly receive the numerical distributing of rolling power and plastic deformation from MARC's RESULTS.Third, the experiment of bimetal rolling has been done, and throughthe comparisons, the simulation is more accurate than the slab method.By way of comparisons of the slab method, simulation of MARC and researching of experiment, the following conclusion and knowledge have been reached in the text: CD The roll bonding rate increase with the increase in the rate of mean shear yield stresses of clad and core layer metal, but if the rate of mean shear yield stresses of clad and core layer metal is too small, the roll bonding point can not be found;(2)Contact length increase with the increase in the reduction, but the relative bonding length don't comply increase with the increase in the reduction, increases first and then decreases with increasing reduction, so the maximum value for relative bonding length must occurs;(3)The relative bonding length increase with the increase in the frictional factor; (4) As the shear yield stress increase, the thickness of sandwich sheet at the exit is larger; ?The relative bonding length decreases with the increase in the rolling speed, it is said that smaller rolling speed benefit the roll bonding.