Influence of Electron Beam Additive Manufacturing Process Parameters on Structure and Properties of Austenitic Stainless Steel 321

Introduction. In modern industrial and scientific-technical sphere the problem of details formation from various metals and alloys by additive methods is one of the most critical and demanding timely decision. This is primarily due to the need to produce large, complex shaped parts with high productivity and as little waste as possible. One of the most applicable methods for the formation of products by additive method is electron beam wire-feed technology. With use of wire filament and an electron beam for melting in a printing zone it is possible to obtain details with high productivity and acceptable indicators of final structure and mechanical properties. However, interrelation of received structure and mechanical properties depending on parameters of electron beam additive manufacturing process nowadays insufficiently presented in the literature. In this regard, the purpose of this work is to analyze the influence of additive electron-beam production process parameters on the formation of products from SS 321. Results and discussion. Electron beam current, linear printing speed, and wire feeding ratio are used as variable parameters, and the ultimate tensile strength is taken as the optimization parameter. Optimal parameters of the electron beam current (40 mA), printing speed (180 mm/min) and wire feeding ratio (1.3) at constant accelerating voltage (30 kV) are established. These parameters allow forming the product without defects and without melting the previously formed layers with the ultimate tensile strength of 583 MPa. It is shown that the use of the highest values of printing speed (320 mm/min) and wire feeding ratio (1.3) at varying the electron beam current does not allow to perform the sample formation process. It is established that at the parameters of the electron beam additive manufacturing process, which provide the complete formation of the product, the structures obtained in materials achieve ultimate tensile strength within 558-595 MPa.