The influence of microstructure deformation on the corrosion resistance of cold formed stainless steel

Abstract

Rotary swaging is an incremental cold forming process to produce axisymmetric workpieces from rods and tubes. The process also induces changes of the microstructure of the material depending on the process parameters. This in turn influences the mechanical properties like hardness as well as the electrochemical properties. As a result of changed electrochemical properties, the passivity of the material and thus the corrosion behavior changes. In order to investigate the influence of rotary swaging on the corrosion behavior of the stainless steel AISI304, deformed micro parts are electrochemically analyzed. The measurements reveal a dependency of corrosion rate and impedance on both feed velocity and final diameter of the rotary swaging process. A higher feed velocity decreases the corrosion rate and increases the impedance indicating a better resistance against corrosion as a side effect of rotary swaging.

Nano-Gradient Materials Prepared by Rotary Swaging

“…In addition, because of the significant strengthening effect with low strain [40] and excellent grain refinement ability [48], RS is employed to fabricate the workpieces with ultrafine-grained (UFG) structure or even NG structure. Recently, RS processed materials were reported to exhibit excellent mechanical [40,41,[49][50][51][52][53], fatigue [54][55][56], corrosion [57][58][59][60], tribological [61], electrical properties [61][62][63], etc. We will discuss them in detail in Section 3.…”

“…Additionally, compared with the edge (Figure 5b-2), the center has a higher density of dislocations (Figure 5c-2) i.e., a dislocation density-gradient. Hence, the authors consider the high Recently, RS processed materials were reported to exhibit excellent mechanical [40,41,[49][50][51][52][53], fatigue [54][55][56], corrosion [57][58][59][60], tribological [61], electrical properties [61][62][63], etc. We will discuss them in detail in Section 3.…”

“…Reproduced with permission from [40]. Copyright Taylor & Francis, 2021 Generally, RS can improve the corrosion resistance of the FCC materials [57][58][59][60]. For instance, Bösing et al investigated the corrosion resistance of RSed stainless steel in phosphate buffered saline (0.2 M NaCl + 0.1 M phosphate buffer solution) and found that a smaller grain size leads to a lower corrosion current density and a higher impedance, pointing to a better resistance against corrosion.…”

“…Recently, RS processed materials were reported to exhibit excellent mechanical [ 40 , 41 , 49 , 50 , 51 , 52 , 53 ], fatigue [ 54 , 55 , 56 ], corrosion [ 57 , 58 , 59 , 60 ], tribological [ 61 ], electrical properties [ 61 , 62 , 63 ], etc. We will discuss them in detail in Section 3 .…”

Microstructure Adjustment of Spherical Micro-samples for High-Throughput Analysis Using a Drop-on-Demand Droplet Generator

“…High-throughput methods allow evaluating a large number of samples based on their properties such as thermal stability [1], phase composition [2], hardness [3,4], formability [5,6,7,8], machinability [9], or corrosion behavior [10]. The high-throughput methods for structural materials require samples to have a defined microstructural state since it can be as influential as the materials’ composition in determining material properties [11].…”