Corrosion behavior of the high‐strength low alloy steel welded joint in natural seawater

Abstract

In this work, the corrosion behavior of high-strength low alloy (HSLA) steel welded joints in natural seawater solution was investigated by electrochemical and immersion tests. The experimental results prove that the corrosion resistance of the weld metal (WM) was higher than that of the base metal (BM). The scanning Kelvin probe results show that the potential distribution of the BM zone is lower than the heat-affected zone (HAZ) and WM zone. The scanning vibrating electrode technique results demonstrate that the initial attack for the HSLA welded joint majorly took place in the BM zone after immersion in natural seawater. The corrosion morphology of the HSLA welded joint after immersion was observed by scanning electron microscope. The corrosion morphology of BM and HAZ regions tends to be uniform corrosion, whereas it is mainly pitting corrosion for the WM zone.

Study on the passive behavior of 304 stainless steel under temperature variation

“…Before SKP measurements, the potential of the probe was calibrated with a copper/copper sulfate electrode according to the literature. [9] The obtained SKP potentials were given versus the standard hydrogen electrode.…”

“…From Figure 7, the Fe 2p 3/2 spectra of 304 SS samples can be deconvoluted into four peaks at 707.2 ± 0.2, 708.3 ± 0.2, 710.9 ± 0.2, and 713.0 ± 0.2 eV, respectively, corresponding to Fe (met) , FeO, Fe 2 O 3 , and Fe(OH) 3 species, respectively. [1,9,24] The O 1s spectra can be separated into two components, OH -(531.5 ± 0.1 eV) and O 2− (530 ± 0.1 eV). [9,20] The strength of the peak for OHis more evident than that of O 2− , implying that the hydroxide dominates the composition of the passive film rather than oxides.…”

“…[1,9,24] The O 1s spectra can be separated into two components, OH -(531.5 ± 0.1 eV) and O 2− (530 ± 0.1 eV). [9,20] The strength of the peak for OHis more evident than that of O 2− , implying that the hydroxide dominates the composition of the passive film rather than oxides. The content of O 2− decreases with the increase of temperature, which further suggests the protective effect of the oxide film (Cr 2 O 3 and Fe 2 O 3 ) is weakened at 90°C.…”

An Investigation into the Factors and Mechanisms Underlying Corrosion Failure of B10 Copper Tubes in Shipboard Pipelines

“…Despite these efforts, the seawater corrosion failure mechanism of B10 copper tubes remains complex and difficult to control, as highlighted by previous studies [9][10] . It is also worth noting that current corrosion failure studies on B10 copper tubes are primarily limited to laboratory-based simulations of environmental conditions, rather than analyses of real working conditions or failure parts [11][12] . Therefore, it is crucial to strengthen corrosion failure research on B10 copper-nickel tubes under actual operating conditions and analyze their failure mechanisms to improve system reliability, extend tube life, modify piping structures, and reduce maintenance costs.…”