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In the laser cladding process, control of the process parameters and knowledge of the characteristics of the materials used are essential for obtaining depositions with excellent metallurgical union, satisfactory dilution values, absence of defects, and acceptable geometric characteristics. Without such precautions, depositions can exhibit low or excess dilution, low wettability, and the presence of pores, consequently reducing the performance of the materials. The aim of the present work was to evaluate the effects of the laser beam power, with maximum power of 4000 W and continuous wave mode, and scanning speed in laser cladding processes employing the AISI 316L austenitic stainless steel and the AISI 431 martensitic stainless steel, considering the geometric characteristics, dilution, and structural defects of the depositions. It was found that the laser power had a greater effect on the width and dilution of the depositions, while the scanning speed influenced the deposition height. The depositions of AISI 431 steel presented dilution values between 9 and 25%, using power settings between 1400 and 1600 W. The depositions of AISI 316L steel required higher power values between 1900 and 2600 W to achieve dilution values between 15 and 41%. The existence of pores and satisfactory hardness values were observed for both materials, with the average of microhardness of 522 HV0.5/15 and 356 HV0.5/15 on the AISI 431 and AISI 316L depositions. It was also found that the different characteristics of the addition metals, considering their morphology, particle size distribution, and flow rate, led to significant changes in the geometric features of the depositions.

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The cladding process aims to improve mechanical, chemical, and physical features in metal surfaces.The laser cladding process is frequently used to promote such alterations through deposition of metals/alloys with superior mechanical behavior on the substrate. In this contribution, an ASTM A36 mild steel was covered with AISI 316L reinforced with NbC powder as a ller metal using multiple laser deposition steps. The effect of the studied parameters on the geometry, surface appearance, dilution, and macrostructural features were evaluated. The laser power, deposition speed, and powder ux were altered, while the other parameters were kept constant. Increases in power and scanning speed resulted in increased dilution region, whereas the coating material rising led to decreased dilution. The welding speed and the powder ow strongly in uence the penetration in the bead-on-plate deposits. This behavior was attributed to the beam's interaction with the substrate due to the named shadow effect. The metal ow in the deposit is governed by the Marangoni effect, which in the case of the laser process presents a single upward ow direction in the center and descending from the surface and the sides, which determines the location of the particles and pores when used 10% of NbC reinforcing particles. For 30% NbC, particle distribution and porosities are homogeneous inside the pool, due to the more signi cant agitation produced by the NbC. The porosities are associated with the particles' dragging of gas towards the pool and NbC precipitate dissolution. IntroductionComponents and equipment need to be reliable and suitable for their applications in face of severe environmental conditions, such as elevated temperatures and pressures, corrosive atmosphere, and high mechanical loads [1, 2] Rigorous procedures and materials are selected in many situations in order to maintain safety and reliability during the operations [3, 4]. In this context, the development of material and the optimization process are required to achieve a such high demanding application.Concerning the increasing demand for the materials and the necessity of reducing the costs from industry, it's frequently unsuitable to use unique material to accomplish all the requirements. Thus, an application of a higher performance coating, as those applied by laser cladding, could be a solution for these demands [5, 6]. Laser cladding creates a metallurgical bonding with substrate and, compared to conventional coating processes, produces low porosity, minimal dilution, little distortion of the base metal, and a small heat affected zone [7][8][9][10][11].The coating, compared with the substrate material, should present some improved features, which allow complementing the properties of the substrate, forming combined and synergetic properties that, together, present greater performance against different mechanical and environmental stresses [5,12]. Many studies with the employment of composite coatings have been conducted [13][14][15][16][17], which the abrasive wear, highly re...