Study On Casting Process And Influence Parameters Of Hall Anchor Fluke

Anchor is an indispensable equipment to ensure the safety of the ship.There are many sites for Hall anchor fluke.However there are some defects such as wrapping gas,shrinkage porosity and shrinkage in the castings with the complicated structure,so that the casting failure rate is about 50%.The actual production needs to spend a large amount of manpower and material resources to improve the process of the product,Consequenly this work combined the casting numerical analysis technique to study the casting defects of Hall anchor fluke.The causes of the casting defects of Hall anchor fluke were studied,and casting process was improved by making reasonable suggestions for the casting defects.The influence of process parameters on casting quality was also investigated.What’s more,the effective method to remove residual stress of castings was provided,which provides guidance for the actual production of the Hall anchor fluke.The main contents of this paper are as follows:(1)Three-dimensional model was established,after analyzing and studying structure and working condition of Hall anchor fluke,the initial casting process was simulated by numerical simulation software MAGMA.By analyzing the flow field and the temperature field in pouring filling,cooling and solidification process of the Hall anchor fluke.The possibility of casting defects in the casting process of hall anchor was predicted.It is found that the fluid flow in the cavity is not smooth,and there are spatter,swirl and air entrainment,etc.,the shrinkage cavity and shrinkage of the large area after solidification,and the residual stress are too high.(2)The foundry process and gating system were redesigned,according to the casting theory,combined with the original casting process of Hall anchor fluke,And the casting defects were obviously reduced by the numerical simulation of the optimized gating system,and the flow field and the temperature field during the filling process,cooling and solidification process.Compared with the existing technology,the casting defects such as shrinkage cavity,shrinkage cavity and heat joint are reduced obviously,and the residual stress is also reduced.(3)By using orthogonal test method and surface response method to study casting process and find influence parameters of Hall anchor fluke,combined with the numerical simulation results,the three parameters of pouring temperature,pouring time and preheating temperature were studied.The influence degree of parameters on casting quality and the optimum process parameters were obtained.By studying the flow field and temperature field of the optimal parameters,the shrinkage rage of the casting are determined,and the residual stress condition is obtained,and the best quality hall anchor claw casting is obtained to guide the actual production.(4)Using MAGMA by analyzing residual stress removal method,to simulate heat treatment of castings with optimum casting process and parameters,the removal of residual stress of castings was studied.It was used to further reduce residual stress,improve casting quality.What’s more,production efficiency can be improved and production cost reduced.