Adherence Measurements and Corrosion Resistance in Primer/Hot-Dip Galvanized Steel Systems

Abstract

OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This paper focuses on the adherence during ageing of a primer (made of polyester resins crosslinked with melamine) applied onto hot-dip galvanized (HDG) steel for coil coating application and its influence on corrosion protection. A chromium-free surface treatment, composed of fluorotitanic acid, phosphoric acid, manganese phosphate, and vinylphenol was applied on the HDG steel to obtain high corrosion resistance and high adherence of a polyester and melamine primer. The influence of the manganese phosphate on the corrosion and adherence was investigated. To measure the adherence between the metal and the primer, a three-point flexure test was set up. The adherence was then linked with corrosion resistance during ageing, using electrochemical impedance spectroscopy.

Practical adhesion measurements of protective coatings on bronze by three-point bending test

“…2b. 6,[23][24][25] Since the failure took place in the elastic domain, the maximum load corresponding to the breaking load F max (i.e., the load at failure) can be considered to be well representative of practical adhesion. Low F max standard deviation values (< 10%) were achieved, with the exception of data for the coated patinated bronze test specimens after accelerated aging, which is discussed in the ''After accelerated aging'' section.…”

“…The adherence measurement method by means of the three-point bending, which is described in references (6) and (24), was carried out according to the standard ISO 14679-1997. The experimental procedure includes the mounting of a stiffener quadrangular block directly onto each coated coupon (10 mm 9 50 mm).…”

“…Coupled studies of adherence with accelerated aging are also of great interest for the assessment of the long-term behavior of coatings. [6][7][8][9][10][11][12] In cultural heritage studies aimed at the conservation of ancient metallic materials 1 the stability and good adhesion of coatings after aging in condensed moisture conditions is difficult to achieve. Such a combined approach could be very important, although so far it has not really been investigated thoroughly.…”

Improvement of adherence and anticorrosion properties of an epoxy-polyamide coating on steel by incorporation of an indole-3 butyric acid-modified nanomagnetite

“…25 mm 9 5 mm 9 4 mm stiffener epoxy blocks were made according to the ISO 14679-1997 Standard, and as described in previous work. 26 Stiffener block polymerization was carried out at ambient temperature (23 ± 2°C) for 24 h. Then, the assembly was sequentially placed in a dry oven at 60°C for 3 h and at 120°C for 1 h. An Instron 3367 tensile testing machine (Norwood, MA, USA) was used with a 5000 N full-scale load cell with a sensitivity of ±0.5% of the measured values, and a crosshead displacement speed of 0.5 mm min À1 (±0.5%). Bluehill software (Instron) controlled the apparatus parameters.…”