Influence of Pulsed Arc Parameters on the Tig Welding Process for the Stainless Steel Duplex UNS S31803

Materials (Basel). 2023 Oct 26;16(21):6870. doi: 10.3390/ma16216870.

Abstract

The influence of parameters involved in the pulsed electric arc, used as an energy source in the tungsten inert gas (TIG)-mediated welding of Duplex UNS S31803 stainless steel, to attend the manufacture of flexible pipes for the extraction of oil and gas is presented. A fundamental part in the manufacturing process of flexible pipelines is the welding of these strips so that corresponding TIG welds will be subjected to the same process and work conditions. Therefore, it is necessary to maintain the same properties in the welded regions. Covering the effects of each parameter of the pulsed electric arc such as peak and base current as welds, cyclic ratio, and pulsation frequency is a desirable endeavor. The final objective is the mitigation of problems that have a great impact on production, such as weld breakage during the conformation of the strip in the process and test failures. With this, tensile, bending, and ferrite percentage tests were performed on 12 samples that qualified as satisfactory in the visual aspect. A minimum tensile strength of 734.57 MPa and a maximum of 775.77 MPa were obtained where all values found are above the tensile strength limit of the base material of 620 MPa. With the completion of the study, it is possible to understand not only the response of the process to each parameter but also the tendency when changing them. Moreover, it is possible to explore the possibility of guiding the changes to achieve results about the visual aspect and the mechanical properties of the welded material.

Keywords: cyclic ratio; microstructure; post weld heat treatment; pulsation frequency; stainless duplex steel.

Grants and funding

This research was funded by the State University of the Northern Fluminense (UENF) and partially financed by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brazil), CNPq (Coordenação Nacional de Pesquisa), and FAPERJ (Fundação de Apoio à Pesquisa do Estado do Rio de Janeiro). The participation of A.R.G.A. was sponsored by FAPERJ through the research fellowships proc.no: E-26/210.150/2019, E-26/211.194/2021, E-26/211.293/2021, and E-26/201.310/2021 and by CNPq PQ2 307592/2021-9.