Otimização da morfologia do revestimento AWS A5.9 ER316LSI em ASTM A36 depositado via processo MIG/MAG –PV

The protection of components and structures through coating techniques is an economically viable solution, but it requires the process and its parameters to be adjusted and tailored for specific applications. The use of non-conventional welding processes, such as MIG/MAG –PV, can achieve weld beads with excellent morphology and low dilution, making the process suitable for coating applications. This is also due to its flexibility, low heat input, and high deposition rate. The objective of this study was to employ the MIG/MAG –PV process using AWS A5.9 ER316LSi filler metal on a free surface (bead-on-plate) in ASTM A36 carbon steel substrate in the 1G position, with dimensions of 70 x 70 x 6.35 mm. For the evaluation, a Box–Behnken Design (BBD) was used with independent variables (Weaving Frequency (Ft), Weaving Amplitude (At), and Welding Speed (Vs)). Response variables were investigated through Response Surface Methodology (RSM) and optimized via the desirability function with maximum height (h) and minimum dilution (D) target, both validated with three replications. The results showed a viable process with excellent surface quality, free from discontinuities and with low spatter values, achieving a maximum width of 26.98 mm, mainly due to weaving amplitude. Additionally, high determination coefficients were obtained, with absolute optimization errors of 0.63% for the maximum height target and 27.61% for the minimum dilution target. Thus, it can be concluded that the process is viable for coating applications, despite the higher absolute error in dilution optimization. This is largely attributed to the non-orthogonality of this response parameter. However, the results showed satisfactory morphological characteristics, as well as surface quality and low dilution.