Finite Element Simulation Of The Temperature Field And Coupling Stress Field Of CrN/Cr Composite Coating Barrel

As the decisive weapon in short-range combat,artillery is widely equipped in many fields such as land,sea and air.The barrel is the core component of the artillery,which is continually served in extremely harsh environment..Nowadays,electroplating Cr coating is a commonly used to protect the artillery barrel,but it is hard and brittle,and its performance and processing technology have not been significantly improved for decades.Compared to electroplating Cr coating,ceramic coatings,such as CrN,exhibits better performance,e.g.high strength,high hardness and good resistance to ablation and abrasion.Therefore,the CrN/Cr composite coating is one of the main development directions for protective coating of the barrel in the future.In order to better explore the temperature field and coupling stress field of the CrN/Cr composite coating barrel,finite element simulation using the software ANSYS Workbench is performed and the outcomes are as follows:First,the temperature field and coupling stress field of the Cr coating artillery barrel were simulated.It was found that the trends of internal wall temperature and stress over time for a single shot and multiple shots are consistent with literature data.The errors in both peak temperature and peak stress are less than 5%.As the number of firings increases,the growth rate of both the peak temperature and the peak stress decreases.These results verify the fidelity of the modeling apporoach(based on finite element simulation)for gun barrel used in the present study.Then,the temperature field and coupling stress field of the artillery barrel with CrN coating was simulated.The temperature of the CrN coating oincreases dramatically with the firing time and then drops sharply.The duration of the high temperature is extremely short,and the inner wall temperature of three sections(e.g.,the bottom of the barrel,the middle of the barrel,and the nozzle)show the same trend with the firing time.The stress of the inner wall changes most drastically with the firing time.The farther the node position from the inner wall,the lower the peak stress and the slower the descending rate.Compared with the results of the Cr coating artillery barrel,it is found that the inner wall temperature of the Cr coating artillery barrel is lower and drops faster.For the CrN coating barrel,it has a higher peak stress and the stress drops faster.Last,the temperature and coupling stress fields of the artillery barrel with CrN/Cr composite coating was simulated,focusing on the temperature and coupling stress of the inner wall and the interface between the coating and the steel matrix as a function of the firing time.During firing,the temperature of the inner wall of the artillery barrel rises firstly and then falls before leveling off.The maximum temperature is higher than that of the Cr coating artillery barrel,but the temperature at the coating/matrix interface is lower.The stress at the internal wall of the CrN/Cr composite coating artillery barrel firstly increases and then decreases slightly,and the stress at the coating/matrix interface decreases more significantly compared to that of the Cr coating barrel.The present study demonstrates that compared with Cr coating,CrN/Cr composite coating can significantly reduce the coating/matrix interface temperature,relax the stress,and as a consequence,effectively protect the artillery barrel.