Measuring corrosion rate and protector effectiveness of advanced multilayer metallic materials by newly developed methods

Vladimir A Grachev,Andrey E Rozen,Andrey A Rozen,Yuri P Perelygin,Sergey Yu Kireev,Irina S Los'

doi:10.1016/j.heliyon.2018.e00731

Abstract

The paper estimates corrosion resistance of new multilayer metallic materials with internal protector against pitting. Using an electron microscope method, the mechanism of the layers' corrosive destruction has been experimentally substantiated. The authors have suggested chemical and electrochemical methods of accelerated corrosion tests allowing for determining the corrosion destruction rate. The electrochemical method reveals the limiting stage of the process and allows calculating the mass corrosion index and substantiating the choice of protector for the specific corrosive medium. The chemical method allows for quantitative assessment of the internal protector's effectiveness and for defining the multilayer/monometallic material corrosion resistance ratio.

Highlights

The issue of pitting corrosion has been a challenge for decades in the context of wide application of high alloy steels and alloys in different segments of industry
Creation of a new class of multilayer metallic materials with internal protector can be the solution to the problem of protection against pitting [1, 2]
A pitting with a diameter of 1.5 mm was formed under the influence of aggressive medium. This indicates that at the initial stage the corrosion damage of the outer layer is analogous to that of a monometallic material when exposed to aggressive medium

Summary

Introduction

The issue of pitting corrosion has been a challenge for decades in the context of wide application of high alloy steels and alloys in different segments of industry. The main research trends in this field are the development of new materials and testing methods, studies of the industrial materials’ behavior in various mediums, and simulation of pitting formation. Creation of a new class of multilayer metallic materials with internal protector can be the solution to the problem of protection against pitting [1, 2]. Such materials contain layers that have different electrochemical potentials and form short-circuited galvanic elements. This architecture fundamentally changes the process of corrosion and extends the material’s operating life. The kinetics of the multilayer metallic material’s corrosive destruction and the mechanism of the internal protector’s action require further study

Objectives

Discussion

Conclusion