Tecnologia em Metalurgia, Materiais e Mineração
Tecnologia em Metalurgia, Materiais e Mineração
Artigo Original

Corrosivity study in Usiminas continuous casting machines segments

Geiciele Mafra de Souza; Meire Guimarães Lage; Alexandre de Freitas Gomes de Mendonça

Downloads: 0
Views: 145


Volatile fluorine compounds are generated in continuous casting processes that use mold flux containing fluorine. The reaction of these compounds with the superheated steam from the secondary cooling system forms hydrofluoric acid, which is corrosive to the metallic structures of continuous casting machines (CCM), mainly in the first segments because there are greater contact between the steam and the fluorine compounds. To obtain knowledge about corrosivity in Usiminas’s CCM and to support taking actions to reduce costs with maintenance, the characteristics of the secondary cooling water were evaluated (pH, alkalinity and ion concentrations) and corrosion coupons were exposed inside the CCM. From the results, it was verified that the water flows and mold flux used in the CCM, which are specific to each type of steel, have a great effect on the water parameters that comes into contact with the structures of the CCM. The corrosion products were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) techniques and. It was observed a predominance of alveolar corrosion and high corrosion rates in the first segments of the CCM. These results helped in the implementation of actions to minimize corrosion in CCM, such as pH monitoring during the process and strict control of sodium hydroxide used in the first segments.


1 Rizzo EMS. Introdução aos processos de lingotamento dos aços. São Paulo: Associação Brasileira de Metalurgia e Materiais; 2006.

2 Chilov A. Mass spectrometric study of volatile componentes in mould powders [dissertation]. Department of Materials Science and Engineering, Helsinki University of Technology; 2005 [cited 2023 Sep 10]. Available at: http://lib.tkk.fi/Diss/2005/isbn9512273276/isbn9512273276.pdf

3 Persson M, Sridhar S, Seshadri S. Kinetic studies of fluoride evaporation from slags. ISIJ International. 2007;47(12):1711-1717.

4 Kashiwaya Y, Cramb AW. Kinetic analysis of NaF vaporization in SiF4-Ar mixture. Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science. 2001;32B:401-407.

5 Takahashi S, Ito J. Fluorine free mold powder. Shinagawa Technical Report. 2019;62:1-4.

6 Wang W, Cai D, Zhang L. A review of fluorine-free mold flux development. ISIJ International. 2018;58(11):1957- 1964.

7 Ruy DR, Santiago PSS, Carvalho VR. Melhoria de processo corrosivo na câmara de vapor da máquina de lingotamento #1 da ArcelorMittal Tubarão. In: Anais do 48o Seminário de Aciaria, Fundição e Metalurgia de Não-Ferrosos; 2017; São Paulo, Brazil. São Paulo: ABM; 2017. p. 867-878.

8 Schulz T. Der einsatz von flussmitteln in der schlackenmetallurgie – Die entwicklung von stranggießpulverschlacken initiiert von D. Janke. In: Metallurgisches Kolloquium zu Ehren von Prof. Dieter Janke; 2016; Freiberg. Freiberg: Technische Universität Bergakademie Freiberg. B 366 Werkstofftechnologie; 2016. p. 71-83.

9 Wang L. Melting properties and viscosity of fluorine-free mold flux for steel continuous casting and its stability [thesis]. School of Materials Science and Engineering, The University of New South Wales; 2017 [cited 2023 Sep 10]. Available at: http://unsworks.unsw.edu.au/entities/publication/eeb9141c-96a9-4e8e-888f-d7540275d4bb

10 ASTM International. ASTM G1-03(2011): Standard practice for preparing, cleaning, and evaluating corrosion test specimens. 9p.

11 Nordesntröm H, Stenback-Lund E. Technology and market study on continuous casting rolls [thesis]. Luleå: Luleå University of Technology; 2006 [cited 2023 Sep 10]. Available at: http://www.diva-portal.org/smash/get/ diva2:1029551/FULLTEXT01.pdf

12 Frazão DM, Melo IR, Montoya M, Urtiga SL Fo. Biocorrosion on surface of ASTM A283 carbon steel exposed in diesel S10 and tap water. Materials Research. 2017;20(2):808-818.

13 Shokri A. An exploration of corrosion in the HF neutralization section at linear alkylbenzene production plant. Iranian Journal of Chemistry and Chemical Engineering. 2020;39(4):127-136.

Submetido em:

Aceito em:

663a13c3a95395095e18b9e5 tmm Articles
Links & Downloads

Tecnol. Metal. Mater. Min.

Share this page
Page Sections