Application of the electrochemical potentiodynamic reactivation method on martensitic stainless steels
- The double loop electrochemical potentiodynamic reactivation (EPR) method is a standardised procedure for detecting and quantifying sensitisation on austenitic, ferritic and ferritic-austenitic stainless-steel grades. This sensitisation is caused by microstructural alternations, as the formation of chromium carbides, nitrides or sigma-phases, which generate local chromium depleted zones nearby. The latter strongly influence the corrosion resistance and the electrochemical response of a stainless steel during electrochemical potentiodynamic reactivation, providing important information on the degree of chromium depletion. In case of martensitic stainless steels, which are used for cutlery and surgical instruments, the heat treatment has a strong impact on the microstructure, the material properties and especially on the corrosion resistance. To study this interaction, the EPR method was modified for the application on martensitic stainless steels with about 13 wt.-% chromium. DifferentThe double loop electrochemical potentiodynamic reactivation (EPR) method is a standardised procedure for detecting and quantifying sensitisation on austenitic, ferritic and ferritic-austenitic stainless-steel grades. This sensitisation is caused by microstructural alternations, as the formation of chromium carbides, nitrides or sigma-phases, which generate local chromium depleted zones nearby. The latter strongly influence the corrosion resistance and the electrochemical response of a stainless steel during electrochemical potentiodynamic reactivation, providing important information on the degree of chromium depletion. In case of martensitic stainless steels, which are used for cutlery and surgical instruments, the heat treatment has a strong impact on the microstructure, the material properties and especially on the corrosion resistance. To study this interaction, the EPR method was modified for the application on martensitic stainless steels with about 13 wt.-% chromium. Different H2SO4 concentrations and EPR-parameters were tested and compared on two standard martensitic stainless-steel grades (AISI 420 A / X20Cr13 and AISI 420 C / X46Cr13) to define applicable parameters. Afterwards, these parameters were used to study the effect of austenitisation time and cooling rate on the corrosion resistance of both martensitic stainless steels. The response of both alloys was different due to the different carbon levels, which will be explained by microstructural investigations in detail. All results allow postulating a process window, in which chromium depletion is suppressed and an optimised corrosion resistance is guaranteed. Based on this research, the modified EPR-test is now used to control the heat treatment and its impact on the corrosion resistance of martensitic stainless steels in the cutlery industry. The EPR-test is thus an interesting alternative for manufacturers, processors, users and researchers to the time-consuming exposition test normally used to characterise the corrosion resistance of martensitic stainless steels.…
Autor*innen: | Paul Rosemann |
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Koautor*innen: | C. Müller, N. Kauss, T. Halle |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 7 Bauwerkssicherheit |
7 Bauwerkssicherheit / 7.6 Korrosion und Korrosionsschutz | |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Corrosion; Corrosion resistance; Corrosion testing; EPR; Heat treatment; Martensitic stainless steels; Stainless steels |
Themenfelder/Aktivitätsfelder der BAM: | Material |
Material / Degradation von Werkstoffen | |
Veranstaltung: | Electrochemical Methods in Corrosion Research 2018 |
Veranstaltungsort: | Cambridge, UK |
Beginndatum der Veranstaltung: | 22.07.2018 |
Enddatum der Veranstaltung: | 27.07.2018 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 01.08.2018 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |