炮钢基电镀铬涂层热震过程仿真与试验研究

Thermal Shock Process Simulation and Experimental Study of PCr Ni3MoVA Based Electroplated Cr Coating

武器身管内膛表面镀层是目前身管武器延寿的重要手段,其中以电镀铬涂层技术最为成熟与经济,而身管内膛硬质铬涂层的抗热震性能是评价镀铬层身管性能的重要指标之一。主要对PCrNi3MoVA基电镀Cr涂层的抗热震性能进行了研究。首先,基于有限元微元体思想,提出一种应力应变分析模型用以表征仿真所得到炮钢铬涂层界面处应力应变变化情况;其次,运用ANSYS软件热-结构耦合场,对炮钢基电镀铬涂层模型的热震过程进行了有限元仿真,并且分析了热震中不同冷却模式(水冷、空冷)下模型膜基界面处应力应变;最后,利用马弗炉对炮钢基电镀铬层试样进行了不同冷却模式的热震试验,观察并分析试验前后试样铬涂层表面形貌与裂纹扩展情况,与ANSYS仿真结果进行了比较。通过ANSYS仿真与试验相结合的方法,分析得到了炮钢基铬镀层在受到高低温交替温度载荷时,水冷却比空气冷却对铬镀层造成的损伤破坏更严重。

The preparation of inner surface coating on gun barrel is an important method to prolong the life of gun barrel. Among them,chromium plating is the most mature and economical technology,and the thermal shock resistance of hard chromium coating in gun barrel is one of the important indexes to evaluate the performance of chromium plated barrel. In this work,the thermal shock resistance of Cr electroplated coating on PCrNi3MoVA was studied systematically. Firstly,based on the idea of finite element microelement,a stress-strain analysis model was proposed to characterize the stress-strain changes at the interface of gun steel chromium coating. Secondly,the thermal shock process of gun steel chromium coating model was simulated by using thermal-structural coupling field of ANSYS software,and the thermal shock process was analyzed. The stress and strain at the film and base interface of model during the earthquake were further studied under different cooling modes (water-cooling and air cooling). Finally,the thermal shock tests of different cooling modes were carried out on the samples of chromium plating on gun steel base using muffle furnace. The surface morphology and crack growth of chromium coating before and after the tests were observed and analyzed,and the results were compared with those of ANSYS simulation. By combining ANSYS simulation with experiment,it was obtained that the damage caused by water cooling was more serious than that caused by air cooling when chromium coating on gun steel was subjected to alternating temperature load.