Banca de DEFESA: ANA PAULA SILVA ARTUR

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STUDENT : ANA PAULA SILVA ARTUR
DATE: 24/11/2020
TIME: 09:06
LOCAL: Google Meet (meet.google.com/yjs-ysgc-uiy)
TITLE:

EVALUATION OF CORROSION BY IMMERSION AND SIMULATION TESTS IN WELDED JOINTS OF STAINLESS STEEL LEAN DUPLEX UNS S32304

KEY WORDS:

Stainless Steel Lean Duplex; Analysis of corrosion resistance; Electrochemical corrosion techniques, Simulation.

PAGES: 129
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

Duplex stainless steels are constituted by an approximately equal volumetric mixture of austenite and ferrite and because of their high resistance to corrosion, their applicability has increased in the daily life of industries. The lean duplex stainless steel UNS S32304, study material in this research, when compared to other types of duplex stainless steels, has a relatively lower cost of obtaining, due to the partial substitution of nickel for nitrogen as an alloy element. This work hat to objective analyze the corrosion resistance of lean duplex stainless steel UNS S32304 in time 4 and 8 months immersed in a 3.5%m/v NaCl solution using electrochemical techniques and anodic potentiodynamic polarization and electrochemical impedance in welding processes GMAW, FCAW, SMAW and the base metal. The results demonstrate that the corrosion potential of the joints welded by the GMAW process showed higher values, indicating the smallest tendency of corrosion of these samples, when compared to the other welding processes, this probably occurred due to the lower level of non-metallic inclusions of the GMAW process. As for the corrosion rate test, it was noticed that all samples had a degree of corrosivity at least moderate, except the base metal, which had a low degree of corrosivity. The samples that had the elevated corrosion rate were those of the FCAW weld, demonstrating the environment this studied was more corrosive for samples welded by this process. In the simulated results when compared to those obtained experimentally and with the literature they were consistent, however in the simulated part it is not possible to identify which type of weld and therefore this information is only obtained experimentally, but the simulation was very important, as it presents general information of the corrosive process and its application under specific conditions brings results similar to those found experimentally in a much shorter return time. This simulation process still allows a general notion of the corrosion behavior in the same experimental condition with two different materials.

BANKING MEMBERS:
Interno - 1811284 - EDSON ROMANO NUCCI
Interna - 1615536 - DALILA MOREIRA DA SILVEIRA
Externa à Instituição - VANESSA DE FREITAS CUNHA LINS