| AVS 66th International Symposium & Exhibition | |
| Fundamental Aspects of Material Degradation Focus Topic | Thursday Sessions |
| Session DM+BI+SS-ThM |
| Session: | Material Stabilities and Technology for Degradation Protection |
| Presenter: | Ines Traxler, CEST Competence Centre for Electrochemical Surface Technology, Austria |
| Authors: | I. Traxler, CEST Competence Centre for Electrochemical Surface Technology, Austria G. Schimo-Aichhorn, CEST Competence Centre for Electrochemical Surface Technology, Austria A. Muhr, voestalpine Stahl GmbH, Austria G. Luckeneder, voestalpine Stahl GmbH, Austria H. Duchaczek, voestalpine Stahl GmbH, Austria K.-H. Stellnberger, voestalpine Stahl GmbH, Austria D. Rudomilova, University of Chemistry and Technology Prague, Czech Republic T. Prosek, University of Chemistry and Technology Prague, Czech Republic B. Lutzer, CEST Competence Centre for Electrochemical Surface Technology, Austria D. Stifter, Johannes Kepler University Linz, Austria S. Hild, Johannes Kepler University Linz, Austria |
| Correspondent: | Click to Email |
High-strength steels are important materials for the automotive industry. Due to their good formability and high strength they are used for the manufacture of light weight and fuel-efficient automotive parts. A disadvantage of high strength steels is their proneness to hydrogen embrittlement. Even small amounts of hydrogen can cause a deterioration of mechanical properties. Therefore, the effect of hydrogen on the steel microstructure is of great interest and it is important to study and visualize the effects and mechanisms of hydrogen in steels. For this purpose, Scanning Kelvin Probe Force Microscopy (SKPFM) is a promising technique for the investigation of hydrogen in the steel microstructure with a very good spatial resolution.
Hydrogen diffusion in different high-strength steels was investigated using SKPFM. Hydrogen entry at cut edges and coating defects was studied as well as the influence in the individual steel grains. The measurements were carried out with different salt solutions on the backside of CP1000 (complex phase), DP1000 (dual phase) and zinc coated DP1000 steels to induce corrosion and promote hydrogen entry into the steel. The permeating hydrogen was measured on the upper side of the sample by repeated surface scans and the effect on the contact potential difference (CPD) was studied. Furthermore, SKPFM measurements with different relative humidity were carried out, monitoring the effects of corrosion. Additionally, Scanning Kelvin Probe (SKP) measurements were done for comparison.
With SKPFM, the preferred diffusion pathways of hydrogen through the steel microstructure could be visualized as well as the effect of zinc coatings on hydrogen permeation.