TY - JOUR
T1 - Characteristics of blueing as an alternative chemical conversion treatment on carbon steel
AU - Onofre-Bustamente, E.
AU - Domínguez-Crespo, M. A.
AU - Genescá-Llongueras, J.
AU - Rodríguez-Gómez, F. J.
N1 - Funding Information:
This study has been financed by the DGAPA PAPIIT IN 115603-Project, DGAPA-UNAM and CONACYT. Special thanks to Ivan Puente L. for SEM measurements.
PY - 2007/1/15
Y1 - 2007/1/15
N2 - Alternative pretreatments are proposed in order to avoid the environmental aggressive impact produced by using surface finishing processes based on Cr(VI) compounds. In this work, blueing method is proposed as chemical conversion treatments (CCTs) in AISI 1010 commercial steel. CCTs were carried out by the so-called "Swiss blueing" method using a solution with 20 g HNO3 + 5 g CH3CH2OH + 5 g CuSO4·5H2O + 160 g FeCl3 dissolved in water (1:1). This solution was added onto steel sheets using spray impregnation technique. Anticorrosion protection and adhesion properties were evaluated using polarization resistance (Rp), ac impedance and pull-off test, respectively. The thickness, morphology and microstructure of the protective films have been examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Although, no-treated specimens showed the highest polarization resistance (Rp) and impedance values, the oxide compounds are porous and unstable, while samples with the CCTs increased anticorrosive protection and favoured a strong adhesion between substrate and top coating. Continuous immersion values obtained by ac impedance showed remarkable variations in the coating resistance. SEM micrographs indicate that chemical treatment increased the surface porosity-roughness. XRD patterns showed some iron oxide compounds: mainly magnetite, and a small quantity of hematite, which have influenced the electrochemical behavior and adhesion. Pull-off tests showed good adhesion in the previously treated samples. These results indicate that obtained roughness with one CCTs using "Swiss blueing" method increased anticorrosion protection and adhesion properties.
AB - Alternative pretreatments are proposed in order to avoid the environmental aggressive impact produced by using surface finishing processes based on Cr(VI) compounds. In this work, blueing method is proposed as chemical conversion treatments (CCTs) in AISI 1010 commercial steel. CCTs were carried out by the so-called "Swiss blueing" method using a solution with 20 g HNO3 + 5 g CH3CH2OH + 5 g CuSO4·5H2O + 160 g FeCl3 dissolved in water (1:1). This solution was added onto steel sheets using spray impregnation technique. Anticorrosion protection and adhesion properties were evaluated using polarization resistance (Rp), ac impedance and pull-off test, respectively. The thickness, morphology and microstructure of the protective films have been examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Although, no-treated specimens showed the highest polarization resistance (Rp) and impedance values, the oxide compounds are porous and unstable, while samples with the CCTs increased anticorrosive protection and favoured a strong adhesion between substrate and top coating. Continuous immersion values obtained by ac impedance showed remarkable variations in the coating resistance. SEM micrographs indicate that chemical treatment increased the surface porosity-roughness. XRD patterns showed some iron oxide compounds: mainly magnetite, and a small quantity of hematite, which have influenced the electrochemical behavior and adhesion. Pull-off tests showed good adhesion in the previously treated samples. These results indicate that obtained roughness with one CCTs using "Swiss blueing" method increased anticorrosion protection and adhesion properties.
KW - Blueing
KW - Chemical conversion treatment
KW - Coatings
KW - ac impedance
UR - http://www.scopus.com/inward/record.url?scp=33845436439&partnerID=8YFLogxK
U2 - 10.1016/j.surfcoat.2006.10.006
DO - 10.1016/j.surfcoat.2006.10.006
M3 - Artículo
SN - 0257-8972
VL - 201
SP - 4666
EP - 4676
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
IS - 8
ER -