Analysis Of Strip Stamping Properties Of A Inconel

Springs are important characteristic constituents making up a nuclear fuel assembly strip and are mainly used to clamp the zirconium alloy fuel tube in place and prevent the fuel tube from shaking.This paper focused on spring characteristics as the research object and started by studying the formation quality of spring characteristics with the maximum thinning ratio used as the assessment indicator.A mechanical property experiment was conducted to determine the required material parameters for the subsequent finite element simulation,and a finite element model for spring forming was established.A highly-precise prediction model for springs’ maximum thinning ratio was then put together from the combination of simulation data and a random forest algorithm.These models were then adopted in a monofactor analysis on the influencing processing parameters for spring forming,before carrying out a comprehensive physics experiment on the stamping performance of a Inconel.The main content of this paper can be summarized as follows.Tensile experiments were carried out to determine the parametric mechanical properties,e.g.,elastic modulus,Poisson’s ratio,thickness anisotropy coefficient,and tensile strain hardening exponent pertaining to specific material properties.Then,the forming limit curve was experimentally generated to provide a technical basis for studying the forming limits of a Inconel alloys and evaluating their sheet-form formability.This paper modeled springs’ characteristics in 3D using Solid Works,and imported the initial model to Hyper Mesh for mesh division and generation.Finally,the finite element model for the stamping process was created in Dynaform and the computations for the stamping simulation run using the LS-DYNA solver.The simulated color-coded diagrams for the finite element model’s forming limit and maximum thinning ratio were then generated.Monofactor sensitivity analysis was then performed,through which the magnitude of influence associated with the processing parameters cou ld be preliminarily determined.The ranges of processing parameters were determined according to actual stamping press data and stamping experience.The simulation experiment plan was determined with the help of Latin hypercube sampling,after which finit e element simulation and data collection were carried out.Next,the process parameters and maximum thinning ratio were mapped using the random forest algorithm.Then,an analysis of the relationship between the process parameters and the maximum thinning ratio was able to confirm the accuracy of the initial hypothesis derived from the monofactor analysis.By performing this simulation on a specific Inconel alloy spring,it was found that the process parameter exerting the highest influence on the formation quality of spring characteristics is blank holder force.Finally,a number of physics experiments on strip stamping performance were carried out to explore whether certain Ni-based alloy meets the stamping requirements of the strip.The results show that the alloy demonstrates satisfactory stamping performance and meets the requirements for strip stamping.