||Diandro Bailoni Fernandes, Edmundo Benedetti Filho, Cristhian Silva Carvalho, JosÚ Martins, Ricardo Schayer, Cristhian Will, Marcy Saturno, Louriel Oliveira Vilarinho
Additive Manufacturing (A M) is a process of joining materials, used to manufacture parts, using data from a three-dimensional model, usually through a layer-by-layer approach (ISO/ASTM 52900, 2015). Among the available approaches, Wire-Arc Additive Manufacturing (WAAM) has been shown to have the highest production capacity and lowest cost. Among the advantages, it is possible to highlight the possibility of manufacturing parts on demand within a short delivery time with specific/directional properties or multiple properties (multigrade material), parts with complex geometry, parts customized by application and even performing topological optimization on existing parts. In higher value materials, low waste is also noteworthy. In this context, the aim of this work is to present the design, manufacture and evaluation of a concentric reduction sleeve from 4” to 3” in carbon-manganese steel, which was firstly installed in a Brazilian Oil and Gas facility in the Sao Paulo Pipeline Master Plan. It is noteworthy that it was decided to make this sleeve as a proof of concept for the validation of the AM technology. The construction of a digital library of items that can be manufactured on demand is expected to reduce logistics and infrastructure costs. Initially, the concentric reduction sleeve was design for coupling 4” to 3” diameter pipes, according to ASME B16.3 (2016), ASME B1.20.1 (2013) and ASTM A197 (2019) standards. The original sleeve is manufactured by casting, whose material is ductile cast iron. Additionally, attention was given to standards N-76 (2016) and ASTM A153 (2016), respectively regarding to material, use and coating (galvanizing), as a step after WAAM. The initial design of the sleeve follows the design of ASME B16.3 (2016). As the original material is ductile cast iron and ER70S-6 AWS A5.18 (2005) carbon steel wire (1.2 mm in diameter) was deposited, the expectation was to obtain mechanical properties above the required. For the deposition of the part, a welding power source was used operating with Pulsed MAG process, together with a robot with six degrees of freedom. As deposition parameters, we have wire feed speed of 5.5 m/min, average current of 150 A and travel speed of 84 mm/min were used. A refrigerated torch, a tank for continuous cooling and Ar+4%CO2 at 15 L/min shielding gas were used. The entire process was monitored with appropriate instrumentation, including a thermal camera. After deposition, the piece was evaluated via Nondestructive Testing: Visual, Dimensional, Dye Penetrating Liquid, Conventional Ultrasound and Phased Array Ultrasound and Radiography. After inspected, the part was machined and galvanized according to ASTM A153 (2016) and assembled in the facility of the Sao Paulo Pipeline Master Plan. With a deposition rate of 2.9 kg/h and a final deposited mass of 7.25 kg, the reduction sleeve manufacture was continuously performed in approximately 2.5 h. Visual, Dimensional and Dye Penetrating Liquid inspections showed perfect component sanity, without any discontinuity internally and externally, confirmed by both Conventional and Phased Array Ultrasound inspection. The mechanical properties obtained were above the required in comparison to the component originally made of cast iron: mechanical tensile tests resulted in 354 MPa yield strength and 491 MPa resistance strength with 42% elongation. The fracture toughness measured was 271 J at -30║C. Therefore, the manufactured sleeve was approved in all, without any discontinuity, given that no acceptance criteria were found in the context of Additive Manufacturing. After the physical integrity of the component is confirmed, it has undergone post-processing machining (turning) to adjust the dimensions and manufacture the threads inside. Finally, the component was subjected to the process of hot-dip galvanizing (ASTM A153, 2016), which was an indispensable requirement for its application. Based on the manufacture and evaluation of a 4” to 3” concentric reduction sleeve made of carbon-manganese steel wire, it is possible to conclude tha
t the proc
edure used was adequate and the Wire-Arc Additive Manufacturing technology has great potential for industrial use, specifically in the Oil, Gas and Biofuels Sector. It is expected that the adoption of the technique will bring economics and agility to the projects by allowing the reduction of inventories and the production of spare parts on demand.
Keywords: WAAM; GMA-DED; Pulsed GMA; Carbon Steel