# Investigation of Corrosion Resistance of 60Si2MnA Spring Steel Coated with Zn-Al in Atmospheric Environments

## TL;DR

This study examines how well Zn-Al coated spring steel resists corrosion in atmospheric conditions, finding that coating performance declines over time.

## Contribution

The study provides new insights into the corrosion behavior of Zn-Al coated steel under controlled atmospheric conditions.

## Key findings

- Zn-Al coatings showed good initial corrosion resistance but deteriorated over time.
- Corrosion products included ZnO, Zn(OH)2, and Zn5(CO3)2(OH)6, while red rust consisted of iron oxides and hydroxides.
- Higher temperatures accelerated coating consumption and reduced corrosion resistance.

## Abstract

To investigate the corrosion resistance of 60Si2MnA spring steel coated with Zn-Al in a domestic atmospheric environment containing harmful salts, the corrosion environmental factors (temperature, humidity, deposited salts, and pH) were obtained through field research. The deliquescence and weathering behavior of harmful salts were studied using impedance methods to establish their characteristic curves. Additionally, a self-designed salt deposition test apparatus was employed to conduct accelerated atmospheric corrosion tests under constant salt deposition (10 g/m2) and controlled temperature and humidity conditions (20 °C/75% RH and 40 °C/75% RH) over different corrosion periods. The results show that noticeable red rust appeared on the samples after one month of corrosion. As the temperature increased, the consumption of the coating accelerated. XRD and Raman analyses reveal that the main corrosion products of the coating materials were ZnO, Zn(OH)2, and Zn5(CO3)2(OH)6, while the red rust primarily consisted of iron oxides and hydroxides. In the early stages of corrosion, the self-corrosion current density was relatively low due to the protective effects of the coating and the corrosion product layer, indicating good corrosion resistance. However, in the later stages, the integrity of the coating and the corrosion product layer deteriorated, leading to a significant increase in the self-corrosion current density and a decline in corrosion resistance. This study provides a data foundation for understanding the corrosion behavior of Zn-Al-coated spring steel in atmospheric environments and offers theoretical insights for developing more corrosion-resistant coatings and optimizing anti-corrosion measures.