Study On Process And Microstructure Of Laser-TIG Hybrid Additive Manufacturing For 316 Stainless Steel

With the progress of the times and the development of science and technology,the manufacturing industry is also constantly moving towards the field of new manufacturing.As a rapid prototyping manufacturing technology,additive manufacturing is in line with the current background of resource conservation and efficient manufacturing.Compared with the traditional manufacturing process,additive manufacturing has the advantages of short cycle time,high efficiency,fast forming and low cost.This technology not only shortens the working time and saves raw materials,but also gradually develops into an automated production method,greatly reducing Labor costs.316 austenitic stainless steel has excellent comprehensive performance,and its good corrosion resistance and mechanical properties are widely recognized and loved by people.It is widely used in aerospace,automotive ships and rail transportation.Using 316 stainless steel as a raw material for additive manufacturing can quickly produce excellent structural parts with complex structures and diverse shapes.However,due to the characteristics of stainless steel such as strong fluidity,it is necessary to conduct in-depth research on its additive manufacturing process,optimize the process flow,and improve the dimensional accuracy and performance of the formed parts.In this paper,the additive manufacturing of laser-TIG hybrid fuse is used to study the additive manufacturing process of different structural types of shaped parts,and to deeply explore the formation and changes of its microstructure.In order to obtain better mechanical properties,the main research content and the content of this paper conclusion as below:The laser-TIG arc hybrid additive manufacturing process,the impact mechanism of the laser on the arc is studied.The research results show that: the introduction of laser can have a positive effect on the TIG arc.The laser-induced arc tail contraction reduces the arc area and reduces the arc area.The stability of arc combustion can increase the walking speed of additive manufacturing on the premise of ensuring good forming,which not only improves the manufacturing efficiency but also effectively reduces the heat input.The process,performance and organization of laser-TIG arc hybrid additive manufacturing of thin-walled wall structural parts are studied.The results show that the thin-walled wall structure adopts a single-layer multi-layer reciprocating stacking method,and the horizontal tensile strength is better than In the vertical direction,the strength inside the deposited stripes is higher than the strength between the interface layers.The microstructure is columnar dendrites.As the number of stacked layers increases,the dendrite spacinggradually expands,corresponding to its microhardness gradually decreasing.316 stainless steel is a two-phase structure of austenite and ferrite.A small amount of ferrite is distributed on a large amount of austenite matrix.The ferrite content is related to the chemical composition of the stainless steel raw material.Precipitation is accompanied by a certain direction.The process,performance and organization of thick-walled structural parts manufactured by laser-TIG arc hybrid additive are studied.The results show that the thick-walled wall structure adopts multi-layer multi-layer reciprocating stacking method,and its stacking path can be planned.The formation is good when the coverage between adjacent weld layers is50%.The thick-walled structure has different tensile strengths in all directions due to the different accumulation paths.The direction of heat flow and heat dissipation of the structural parts is complex,and the grain growth direction is perpendicular to the interface.The process of laser-TIG arc hybrid additive manufacturing of round tube structural parts was studied.The research results show that: the laser-TIG arc additive manufacturing method can be used to prepare well-shaped circular tube-shaped structural parts.The thin-walled round tube adopts the single-layer multi-layer stacking method,and the arc starting position of each layer is different.The thick-walled round tube adopts a multi-layer multi-layer stacking method with a coverage rate of 50%,and the stacking order of each layer is from inside to outside.