Título: | IDENTIFICATION AND SOLUTION OF HOT ROLLING CRACKING IN STRUCTURAL STEELS PROCESSED BY CONTINUOUS CASTING | ||||||||||||
Autor: |
CARLOS AUGUSTO RUPPENTHAL MILANI |
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Colaborador(es): |
MARCOS VENICIUS SOARES PEREIRA - Orientador |
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Catalogação: | 18/FEV/2019 | 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=36911&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=36911&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.36911 | ||||||||||||
Resumo: | |||||||||||||
The advent and consolidation of the continuous casting process, currently
dominant in the Steel Industry, raised the increasing investigation and analyses
efforts on the phenomena related to the high-temperature behavior of the steels.
Unlike the conventional ingot casting process, the continuous casting is a dynamic
process in which occurs the mold oscillation while the strand under solidification
is continuously withdrawn and submitted to a secondary cooling operation. In
Brazil, it can be found an industrial park of companies dedicated to the hot rolling
of semis supplied by third parties as steel slabs, which ones are flame cut in the
form of square billets for rolling. The production mix of these companies
encompasses structural steels such as flat bars, round bars, angles and even special
profiles for the machines and automotive industries. A catastrophic series of
quality events related to cracking emerged from the rolling of SAE 1020 billets
made from continuously cast slabs. These cracks, perhaps pre-existing or latent in
the inner parts of the slabs could be exacerbated by thermal affected zones during
the flame-cut operations. The propose solution to overcoming this contingency
was the creation of a replacement steel grade with lower carbon content and
higher alloy content aiming to preserve the mechanical properties of the as rolled
material. Lower carbon contents does not only contributes to the minimization of
the effects arising from the peritetic transformations as also act in favor on the
consequences coming from thermal affected zones. This proposition was well
successful and the chemical composition of this replacement steel called pseudo-
1020 since then became a rolling standard. Samples of the rolled SAE 1020 steel
with cracks occurrences and of the replacement steel were taken and transformed
in specimens for tensile strengths, hardness and impact tests.This paper aims to
present all related phenomena to the occurrence of inner and superficial cracks in
continuously cast steels, in special the ones submitted to peritetic transformations,
and the premises that support the creation of a replacement steel and the related
results.
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