Título: | NI ALLOYED WELD METALS WITH ADDITIONS OF CU AND MO FOR UNDERWATER WET WELDING | ||||||||||||||||||||||||||||||||||||||||
Autor: |
ANA PAULA BECK LEAO |
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Colaborador(es): |
IVANI DE SOUZA BOTT - Orientador VALTER ROCHA DOS SANTOS - Coorientador |
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Catalogação: | 04/MAR/2010 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=15335&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=15335&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.15335 | ||||||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||||||
This work was carried out to improve the mechanical properties of weld
metals deposited by nickel oxidizing electrodes, together with additions of
copper and molybdenum, through the grain refinement or by solid solution
hardening. The oxidizing electrodes are characterized by the lower levels of
diffusible hydrogen and, hence, by the lesser possibility of cold crack formation
when compared to rutile electrodes. However, the weld metal deposited with
this type of electrode shows mechanical properties below that obtained by rutile
electrodes, as long as important alloy elements, such as Mn and Si, are lost by
oxidation. In order to avoid this situation and obtain weld metals with better
mechanical properties it was added alloy elements that are not significantly
affected by the oxidant character of the coating, such as Cu and Mo. Two test
specimens were prepared for welding, where spaced holes and a notch were
machined in each one for the addition of both elements, Cu and Mo. Different
percentages of these elements were measured by Energy Dispersive
Spectroscopy microanalysis. From these results it was performed
microstructural analysis using optical microscopy, grain size measurements and
microhardness tests to evaluate the influence of each element in the weld metal
and compare them to each other. The results showed that molybdenum has a
stronger influence on the microhardness of the weld metal than copper.
Regarding the grain size it was noted an opposite influence of the elements,
where the addition of Mo caused a decrease of the grain size and the addition
of Cu caused a slightly increase, until the grain size becomes constant.
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