Influence of Remelting and Temperature Field on Anisotropy of 316L Stainless Steel in Wire Arc Additive Manufacturing

_ Anisotropy is one of the common problems in additive manufacturing. The texture within the layer and the longitudinal partitioning are closely related to the remelting and solidification temperature field and are the main reasons for the anisotropy of 316L stainless steel in arc additive manufacturing. When depositing the top layer, the maximum height of the remelted metal in the subtop layer in the longitudinal direction is 2.28 mm, whereas the maximum longitudinal height of the zone with no obvious grain directionality at the top of the layer is .988 mm. Therefore, there is a texture throughout the entire layer after remelting. During the solidification process, the temperature gradient and cooling rate vary greatly in different zones within the layer, resulting in a partitioned structure in the longitudinal direction. The average cooling rates of typical nodes in the top, central, and remelting zones of the top layer from 1450 to 800°C are 782.3, 842.5, and 1865.8°C/s, respectively, and the temperature gradients are 1.41 x 104, 5.45 x 104, and 4.55 x 105°C/m, respectively. Keywords remelting; temperature field; anisotropy; 316L stainless steel; wire arc additive manufacturing