Research On The Mechanical Properties And The Security Of Forming Process Of The Clad Steel Plate Used In The Accumulator Tank Of Nuclear Plant

Comparing with the single steel plate, the clad steel sheet has a wider application prospect due to a combination of the excellent properties of different material layers. It plays a significant role, which cannot be replaced by single material plate, especially in the aerospace, petrochemical industry and atomic energy industries. However, due to the different compound method and mechanical mismatch of different material layers, the mechanical properties and structure damage characters of the clad steel sheets are more complex than a single steel plate. At present, the study of clad steel sheets are mainly focused on its manufacturing technology and mechanical properties of the interface. The cyclic deformation characteristics and forming safety of the clad steel sheets need to be further studied. In this paper, the basic mechanical properties, cyclic deformation behavior and the security of forming process of the clad steel plates (304L+533B) used in the accumulator tank of nuclear plant have been carried on as follows:(1) The mechanical properties of composite steel plate around the interface ware obtained by the microscopic observation, micro-hardness test and EDS energy spectrum analysis. Effects of various composite methods on the characteristics and properties of the composite plate interface were discussed.(2) The tensile test of base plate, flyer plate and composite plate at different temperature and the cyclic deformation test at room temperature were carried out. The comprehensive mechanics characteristic of the composite plate and the deformation behavior are discussed. At the same time the material parameters of different metal components of the clad steel plates were obtained.(3) The mechanical properties of the interface were obtained through a small sample in situ tensile experiment combined with digital speckle technology (DIC). And with the material parameters of the base plate and flyer plate which are achieved in (2), the tensile behavior and cyclic deformation behavior of composite steel plate are simulated with FEM and verified with experiments. The effects of mechanical properties of different components on the local stress and strain distribution of deformation process of composite steel plate are discussed, and the characteristics of tensile behavior and cyclic deformation behavior of composite steel plate are obtained, which provides support for the security check of the forming process of the accumulator tank.(4) The security check on the forming process of different composite steel plate in injection box was carried by the finite element simulation using the nonlinear finite element software ABAQUS. It provides support for the optimization of forming technology.