Use of Goethite as an anti-corrosive Pigment

Carbon steel is widely used as a metallic material, despite its limited corrosion resistance. To enhance its anti-corrosion properties, organic coatings such as epoxy are commonly applied due to their barrier mechanism. This study investigates the corrosion resistance of epoxy coatings reinforced wi...

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Main Authors: Matheus Orlandi Pessoa, Jorgimara de Oliveira Braga, Fernando Cotting
Format: Article
Language:English
Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 2025-07-01
Series:Materials Research
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Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392025000200245&lng=en&tlng=en
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author Matheus Orlandi Pessoa
Jorgimara de Oliveira Braga
Fernando Cotting
author_facet Matheus Orlandi Pessoa
Jorgimara de Oliveira Braga
Fernando Cotting
author_sort Matheus Orlandi Pessoa
collection DOAJ
description Carbon steel is widely used as a metallic material, despite its limited corrosion resistance. To enhance its anti-corrosion properties, organic coatings such as epoxy are commonly applied due to their barrier mechanism. This study investigates the corrosion resistance of epoxy coatings reinforced with various ratios of iron oxides and goethite as anticorrosive pigments. The research aims to evaluate the adhesion and anticorrosive properties of waste mineral goethite (α-FeOOH) pigments in comparison to micaceous and red iron oxides. Coating morphology and chemical element distribution were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Electrochemical characterization techniques—including electrochemical impedance spectroscopy (EIS), linear and potentiodynamic polarization, and accelerated salt spray corrosion tests—were employed. Additionally, coating adherence was assessed via pull-off tests. Results demonstrated that goethite-based paints exhibited anticorrosive performance comparable to industrially used red and micaceous iron oxides, regardless of pigment concentration. The results of EIS showed that the 5% goethite formulation reached an impedance modulus of |Z|0.01Hz ≈ 1011 Ω·cm2 after 90 days. However, salt spray results showed that the area with corrosion products around the incision in the painted test specimens was quantified, showing the smallest reduction in corroded areas for the samples with 10 and 20% goethite concentration applied to the coating. These findings highlight the potential of mining waste goethite as a sustainable and effective anticorrosive pigment when properly optimized.
format Article
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institution Matheson Library
issn 1516-1439
language English
publishDate 2025-07-01
publisher Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
record_format Article
series Materials Research
spelling doaj-art-c65a8c8b4649430f9fb26a611b4a58a72025-07-15T07:41:11ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14392025-07-0128suppl 110.1590/1980-5373-mr-2025-0092Use of Goethite as an anti-corrosive PigmentMatheus Orlandi PessoaJorgimara de Oliveira Bragahttps://orcid.org/0009-0002-2962-897XFernando Cottinghttps://orcid.org/0000-0001-5980-0078Carbon steel is widely used as a metallic material, despite its limited corrosion resistance. To enhance its anti-corrosion properties, organic coatings such as epoxy are commonly applied due to their barrier mechanism. This study investigates the corrosion resistance of epoxy coatings reinforced with various ratios of iron oxides and goethite as anticorrosive pigments. The research aims to evaluate the adhesion and anticorrosive properties of waste mineral goethite (α-FeOOH) pigments in comparison to micaceous and red iron oxides. Coating morphology and chemical element distribution were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Electrochemical characterization techniques—including electrochemical impedance spectroscopy (EIS), linear and potentiodynamic polarization, and accelerated salt spray corrosion tests—were employed. Additionally, coating adherence was assessed via pull-off tests. Results demonstrated that goethite-based paints exhibited anticorrosive performance comparable to industrially used red and micaceous iron oxides, regardless of pigment concentration. The results of EIS showed that the 5% goethite formulation reached an impedance modulus of |Z|0.01Hz ≈ 1011 Ω·cm2 after 90 days. However, salt spray results showed that the area with corrosion products around the incision in the painted test specimens was quantified, showing the smallest reduction in corroded areas for the samples with 10 and 20% goethite concentration applied to the coating. These findings highlight the potential of mining waste goethite as a sustainable and effective anticorrosive pigment when properly optimized.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392025000200245&lng=en&tlng=enSAE 1008 carbon steeliron oxidesepoxy coatinggoethite
spellingShingle Matheus Orlandi Pessoa
Jorgimara de Oliveira Braga
Fernando Cotting
Use of Goethite as an anti-corrosive Pigment
Materials Research
SAE 1008 carbon steel
iron oxides
epoxy coating
goethite
title Use of Goethite as an anti-corrosive Pigment
title_full Use of Goethite as an anti-corrosive Pigment
title_fullStr Use of Goethite as an anti-corrosive Pigment
title_full_unstemmed Use of Goethite as an anti-corrosive Pigment
title_short Use of Goethite as an anti-corrosive Pigment
title_sort use of goethite as an anti corrosive pigment
topic SAE 1008 carbon steel
iron oxides
epoxy coating
goethite
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392025000200245&lng=en&tlng=en
work_keys_str_mv AT matheusorlandipessoa useofgoethiteasananticorrosivepigment
AT jorgimaradeoliveirabraga useofgoethiteasananticorrosivepigment
AT fernandocotting useofgoethiteasananticorrosivepigment