Comparison of Crevice Corrosion of Fe-Based Amorphous Metal and Crystalline Ni-Cr-Mo Alloy

Abstract

The crevice corrosion behaviors of an Fe-based bulk metallic glass alloy (SAM1651) and a Ni-Cr-Mo crystalline alloy (C-22) were studied in 4M NaCl solution at 100°C with cyclic potentiodynamic polarization and constant-potential tests. The corrosion damage morphologies, corrosion products, and the compositions of corroded surfaces of these two alloys were studied with optical three-dimensional reconstruction, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Auger electron spectroscopy (AES). It was found that the Fe-based bulk metallic glass (amorphous alloy) SAM1651 had a more positive breakdown potential and repassivation potential than crystalline alloy C-22 in cyclic potentiodynamic polarization tests and required a more positive oxidizing potential to initiate crevice corrosion in constant-potential tests. Once crevice corrosion initiated, the corrosion propagation of C-22 was more localized near the crevice border compared to SAM1651, and SAM1651 repassivated more readily than C-22. The EDS results indicated that the corrosion products of both alloys contained a high amount of O and were enriched in Mo and Cr. The AES results indicated that a Cr-rich oxide passive film was formed on the surfaces of both alloys, and both alloys corroded congruently in the crevice corrosion damage areas.

Corrosion Resistance and Electrocatalytic Properties of Metallic Glasses

“…Fe 52 Mn 10 Mo 14 Cr 4 B 6 C 14 metallic glass is susceptible to pitting corrosion, although presents good corrosion resistance characterized by a low passivating current in 0.6 M NaCl solution [96]. Fe 48 Cr 15 Mo 14 B 6 C 15 Y 2 metallic glass, as known SAM1651, exhibits hysteresis loop during cyclic potentiodynamic polarization in 4 M NaCl solution at 373 K, which indicates the formation of localized corrosion [97]. Pardo et al [58,59] found that FeSiNbBCuCr metallic glass was immune to pitting corrosion in simulated industrial environments, since the current density decreased when the potential scan direction is reversed and it is identified that no pit formed on surface after immersion test.…”

Devitrification of Fe-Based Amorphous Metal SAM 1651: A Structural and Compositional Study

“…[1][2][3] Several Fe-based, exceptionally high corrosion-resistant structural amorphous metal compositions have been developed. [4][5][6][7][8][9][10][11][12][13][14][15] An Fe-based BMG material with a nominal composition of Fe 48 Cr 15 Mo 14 C 15 B 6 Y 2 (SAM 1651) was reported by J. Farmer et al to have high corrosion resistance in hot, concentrated calcium brine as well as in concentrated hydrochloric acid.…”

“…Farmer et al to have high corrosion resistance in hot, concentrated calcium brine as well as in concentrated hydrochloric acid. [4][5][6][7][8] Corrosion-resistant coatings cannot be achieved with thermally sprayed crystalline materials such as 316L stainless steels or Ni-based alloy 22 due to the segregation of undesirable phases, which leads to the loss of their corrosion resistance during the thermal spray process. However, thermal spray coatings of SAM 1651 retained their excellent corrosion-resistant performance as long as the amorphous structure is maintained.…”

Susceptibility of 316L stainless steel to crevice corrosion in submersible solenoid valve

“…The susceptibility of 316L stainless steel to crevice corrosion in a given environment may be assessed in a relatively short time using cyclic potentiodynamic polarization method [25,29,31]. Fig.…”