Desenvolvimento e caracterização de um revestimento de aço inoxidável supermartensítico modificado com 1% de boro pelo processo de aspersão térmica por chama
High severity environments usually require the use of special alloys capable of withstanding the stringent conditions to which they are exposed. The boron modified supermartensitic stainless steel alloy has been developed to withstand corrosion and wear requirements to which pipelines used in oil ex...
| Autor principal: | Oliveira, Dhonatan Junior de |
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| Formato: | Trabalho de Conclusão de Curso (Graduação) |
| Idioma: | Português |
| Publicado em: |
Universidade Tecnológica Federal do Paraná
2020
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| Assuntos: | |
| Acesso em linha: |
http://repositorio.utfpr.edu.br/jspui/handle/1/15189 |
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| Resumo: |
High severity environments usually require the use of special alloys capable of withstanding the stringent conditions to which they are exposed. The boron modified supermartensitic stainless steel alloy has been developed to withstand corrosion and wear requirements to which pipelines used in oil exploration are exposed in order to become a technically and economically feasible option to the current class of materials used for this purpose. Obtaining coatings that can be applied simply, inexpensively, having good efficiency and that can be re-applied if necessary, are essential, especially in situations of wear and corrosion. Thus, this work aims to study the feasibility of obtaining coatings of the supermartensitic stainless steel alloy modified with 1% boron by flame spray process. In addition, it was examined the impact caused by the technique of TIG welding in the deposits. These were characterized by X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), and mechanical tests such as hardness test, tensile test and folding test. The results of the XRD analyzes indicated the predominance of the martensitic phase in the powder and coating samples, with a small presence of austenite and borides. The analysis of the remelted samples suggests an increase in the amount of martensite, as well as the presence of delta ferrite (δ), in addition to a decrease in the amount of austenite and borides. The SEM technique identified the presence of unmelted particles in the non-remelted sample, as well as a considerable presence of oxides, which decreased in the remelted samples. In addition, it was possible to observe the segregation of borides in the grain boundaries of the matrix. The adhesion test did not exhibit any damage to the surface of the coating. In the Vickers microhardness test, good values were obtained for the condition without remelting, obtaining an average of 594.8 HV (10 gf), and this hardness decreases in the remelted sample, reaching an average of 296 HV (10 gf). In the test of tensile strength of the sample without remelting, an average of 8,211 MPa was reached, and the remelting benefited the adhesion of the deposits, obtaining an average of 12,447 MPa. |
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