Corrosion behaviour of experimental copper–antimony–molybdenum carbon steels in industrial and marine atmospheres and in a sulphuric acid aqueous solution

Abstract

Low alloyed carbon steels are used in several applications as in automotive, home appliances and civil industries. Sb-bearing steels have been developed to withstand acid condensation, mainly to exhibit corrosion resistance to sulphuric acid aqueous solutions. This work is aimed at studying the corrosion resistance of three experimental low alloyed carbon steels with additions of copper, antimony and molybdenum using the electrochemical impedance spectroscopy (EIS) in a sulphuric acid aqueous solution, and field tests in industrial and marine atmospheres. The field tests showed the mass loss of antimony-molybdenum carbon steels was higher compared to that of other steels. The alloyed carbon steels with copper and antimony additions showed the highest atmospheric corrosion resistance evaluated by using field tests in industrial and marine environments. The molybdenumbearing steels showed the highest corrosion resistance in a sulphuric acid solution, measured by using the EIS.

Roles of Sb addition on the corrosion resistance of the low‐alloy steel in a real tropical marine atmosphere

“…Sb microalloying is beneficial for improving the corrosion resistance of low‐alloy steel in the marine atmospheric environment. This result is consistent with the conclusion reported in Linus et al, [ 24 ] which showed that Sb inhibited the electrochemical anodic and cathodic processes of low‐carbon steel in both industrial and marine atmospheres, and the phenomenon was explained by the interaction between Sb and Cu.…”

“…Sb microalloying is beneficial for improving the corrosion resistance of low-alloy steel in the marine atmospheric environment. This result is consistent with the conclusion reported in Linus et al, [24] which showed that Sb inhibited the electrochemical anodic and cathodic processes of low-carbon steel in both industrial and marine atmospheres, and the phenomenon was explained by the interaction between Sb and Cu. Usually, there are two time-constants on the surface of low-alloy steel in this kind of experimental system, which are caused by the corrosion products and the electric double layer in the corrosion process.…”

“…EDS quantitative analysis shows that the content of Cl in the CPF is only 0.84%, which is much smaller than that in Sb-free steel, indicating that the CPF after Sb microalloying can better resist the entry of Cl. This result is consistent with that of Lins et al [24] and Wu et al, [16,36] who found that Sb could be enriched in the CPF and interact with Cu to repel the invasion of Cl.…”

“…This claim is also widely accepted by some references. [24,36,43] Considering the fitting error and the limited number of Sb atoms, the effect of Sb addition on pH is significant in the short term but slight in the long term. This is also reflected by the electrochemical results.…”

Corrosion mechanism of a new-type low-alloy corrosion resistant steel containing Sb used in acid environment

“…In the past few years, a Brazilian steel company started the development of antimony-based carbon steels for applications subject to the condensation of sulphuric acid and proved that Sb improved the corrosion resistance (Wu et al, 2020b;Lins et al, 2017;Zhang et al, 2013). Recently, it was found out that Sb addition improved the corrosion resistance of low-alloy steel in acid dew corrosion environment by Nippon Steel (Ahn, 2015;KOJIMA, 2004).…”