Research On Process And Performance Of 316 Stainless Steel TIG Arc Additive Manufacturing

In this paper,316 austenitic stainless steel is manufactured by TIG arc and laser-TIG composite heat source.The range of walking speed,wire feeding speed and arc current was determined and the optimal parameters were determined.The wall size,microstructure and microhardness of the wall were investigated under the optimal conditions.The forming dimensions and microscopic shape of the wall by a single parameter were studied.Based on the appearance and microhardness,based on the optimal parameters,a small power laser was introduced to study the effect of laser power variation on the forming dimensions,microstructure and microhardness of the wall.The arc morphology was studied after laser introduction.And the change of the shape of the molten pool,finally,under the optimal parameters,the round pipe fittings were piled up,and the influence of path change on the wall forming and mechanical properties was studied.The experiments all achieved good results.The results of a single TIG arc study show that in order to obtain a good weld overlay,the welding current and the welding speed should be positively correlated.The change of the tungsten angle is manifested by the change of the action mode of the arc force on the molten pool.When the tungsten angle is not suitable,the height and width of the wall will be unstable.The change of arc current is mainly reflected in the influence of the size of the remelting zone and the grain thickness.The effect of the change of the inter-layer cooling temperature on the wall is realized by changing the metallurgy of the remelting zone.The change of the inter-layer cooling time mainly brings about the drastic change of the wall's high stability.The change in wire feed speed is mainly manifested by the additive effect on the height of the wall.The change in the moving speed is mainly manifested by the stability of the wall width and the additive effect of the height.With the increase of tungsten angle,the uniformity of columnar crystal length increases.As the moving speed increases,the secondary dendrite increases,the columnar crystal continuity becomes better,and the column cooling time increases with the increase of interlayer cooling time.The crystal grows continuously,and as the arc current increases,the secondary dendrite decreases.With the increase of the moving speed,the microhardness of the wall increases continuously.As the wire feeding speed increases,the microhardness of the wall increases first and then decreases.As the cooling time between layers increases,The microhardness of the wall is continuously reduced.As the arc current increases,the microhardness of the wall decreases continuously.As the angle of the tungsten increases,the microhardness of the wall increases first and then decreases.The results of laser-arc additive manufacturing research show that the introduction of low-power lasers improves the wall formation to different extents to obtain a more effective wall thickness.The organization has undergone tremendous changes.The mechanical properties of the formed part are improved and the hardness of the sample is increased.After the introduction of the laser,the arc shape is relatively stable and the arc is slender compared to the single TIG arc,which reduces the flow of the molten metal on both sides caused by the re-impact of the arc on the front layer,and the circle is improved to some extent.The accuracy of the tube sidewall.The laser compresses the arc to concentrate the heat,and the impact of the arc force is also concentrated,so that the molten pool deeper in the vertical direction can be obtained.The experimental results of the tube additive manufacturing show that the tube is stacked with the optimal parameters to obtain a well-formed round tube.Under the condition of single TIG arc addition,the circular tube motion path and the linear motion are similar to the sidewall of the formed part.The mechanical properties of the molded parts and the mechanical properties of the wall are not much different.