Pit initiation in quenching and partitioning processed martensitic stainless steels

Journal article (2024)

Authors

G. Li Team Peyman Taheri - Mechanical, Maritime and Materials Engineering
Z. Li Team Arjan Mol - Mechanical, Maritime and Materials Engineering
E. Rahimi Team Arjan Mol - Mechanical, Maritime and Materials Engineering
M. Muratori Acerinox Europa SAU
Ali Smith RINA
Maria Jesus Santofimia Team Maria Santofimia Navarro - Mechanical, Maritime and Materials Engineering
Y. Gonzalez Garcia Team Yaiza Gonzalez Garcia - Mechanical, Maritime and Materials Engineering
Research Group
Team Peyman Taheri (Mechanical, Maritime and Materials Engineering) (TU Delft)
More Info
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Published Date

2024

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Materials Science and Engineering

Research Group

Team Peyman Taheri

Abstract

The present article investigates the influence of chemical composition and phase fractions on the corrosion behaviour of industrially produced quenching and partitioning (Q&P) martensitic stainless steels. Localised corrosion was analysed by scanning Kelvin probe force microscopy (SKPFM) and scanning electrochemical microscopy (SECM) in 3.5 wt.% NaCl solution. SKPFM revealed a Volta-potential difference of around 40 mV between inclusions and the matrix, which is larger than the Volta potential variations within the matrix. This difference in surface potential is a driving force for selective dissolution (corrosion initiation) at inclusions and inclusion/matrix interfaces. SECM detected early pitting initiation, particularly in alloys containing MnS and TiN inclusions. Results suggest that pitting initiation and propagation occur at those specific regions. This study emphasised that irrespective of chemical composition and phase fraction, localised corrosion initiation in Q&P-processed martensitic stainless steels is predominantly governed by the presence of inclusions.