Avaliação de pré-formas multimateriais em aço carbono e aço inoxidável austenítico depositadas via manufatura aditiva por deposição a arco

Abstract

In this work, the metallurgical evaluation and adhesion at the interface between carbon steel and stainless steel in clad and multimaterial pre-forms (walls) produced by wire-arc additive manufacturing (WAAM) are carried out. Two walls were produced using AWS A5.18 ER70S-6 wires as the base material and AWS A5.9 ER309LSi as the coating material, through coordinated deposition with two welding robots operating in parallel. The walls differed exclusively in terms of the distance between the deposition torches, adopting spacing of 50 mm and 100 mm, keeping all other process parameters constant. The evaluation of the adhesion and integrity of the clad interface was carried out by guided bending tests according to ASTM A264:2019, using bending up to 180°, with the coating maintained in compression. The metallurgical characterization was conducted by optical microscopy, scanning electron microscopy and Vickers microhardness tests, allowing the analysis of the base material, the interface and the coating. The microhardness maps were obtained according to ASTM E384:2011, allowing the evaluation of hardness gradients along the clad interface. The results allowed to correlate the microstructural characteristics and microhardness profiles with the behavior observed in the bending tests, evidencing the influence of the distance between the deposition torches on the formation of the interface and on the integrity of the metallurgical bond between the stainless-steel coating and the carbon steel base material produced by additive manufacturing by arc deposition.