Study On Mechanical Properties Of Stainless Clad Steel

Stainless clad steel is a newly developed high performance composite steel which processes the advantages of both metals in mechanical properties,corrosion resistance and cost.However,the current application of stainless clad steel is mainly concentrated in the industrial field,and the research on stainless clad steel is still very limited,mainly focusing on the manufactory,corrosion resistance and welding.The mechanical properties of stainless steel clad were studied through both experimental researches and finite element simulations in this thesis.The monotonic and cyclic loading tests of stainless steel clad were carried out.The monotonic constitutive model and its simplified form which are suitable for stainless clad steels were proposed.The cyclic mechanical behavior of the stainless steel clad plate was studied.The mixed hardening model suitable for the stainless clad steel was calibrated based on the cyclic loading tests.The main work and conclusions of this thesis are as follows:(1)6 specimens of base metal and clad metal as well as 18 clad steel specimens with different clad ratios under monotonic loading were tested.The basic mechanical properties of stainless clad steel and its base and cladding materials were extracted and analyzed.The results show that the monotonic mechanical properties of the stainless clad steel composite plate vary significantly with the clad ratio.The properties of the base metal and cladding metal conduct a significant effect on the performance of the stainless clad steels.(2)The general finite element analysis software ABAQUS was chosen to simulate and analyze the monotonic specimens of stainless clad steel.The simulations of the four specimens with different clad ratios which were not covered by the experiments were completed after the finite element model was verified by comparing the results between numerical and experimental tests.The results of finite element model established are well fitted with the experimental results.Therefore,the obtained numerical results can be trusted for further analysis of the mechanical properties for stainless clad steels.(3)Based on the test data and finite element simulation results,a three-stage nonlinear monotonic constitutive model for stainless clad steels was proposed.The mechanical parameters in the model were predicted based on the clad ratio and the basic mechanical properties of base and cladding metal.A multi-linear constitutive model which is adjustable according to the designing needs was presented by simplifying the three stage nonlinear constitutive model.The mechanical behaviors of the stainless clad steel under monotonic loading can be well predicted by the three-stage nonlinear model.The simplified multi-linear model is a better choice for balancing both accuracy and efficiency.(4)The cyclic loading tests of the stainless clad steel under 14 different protocols were carried out.The macroscopic failure mode,plastic behavior,ductility characteristics under cyclic loading were analyzed.The skeleton curves were well predicted by Ramberg-Osgood model.The quantitative analysis of the energy dissipation capacity of the stainless clad steel were carried out.The Chaboche mixed hardening cyclic constitutive model was calibrated for stainless clad steel.