Work Item
ASTM WK72764

New Guide for Determination of Corrosion Rate with Electrochemical Harmonic Measurement and Analysis

1. Scope

1.1 This guide covers an experimental procedure for running electrochemical harmonic measurement in the laboratory, determination of the harmonic current and corrosion rate with harmonic analysis. Corrosion current can be calculated by applying harmonic analysis (HA), which is a new standard to measure and monitor the corrosion rate of metals in the corrosive environment. 1.2 This guide covers mathematical derivation and analysis of corrosion rate of metal with electrochemical harmonic analysis and Electrochemical Frequency Modulation. 1.3 This guide does not cover detailed determination of the accuracy for testing the instrumentation, while it covers the comparison of corrosion rate of metals between Electrochemical Harmonic Measurement and Potentiodynamic Polarization Resistance. 1.4 This guide covers specimen preparation, test environment, experimental procedure, data manipulation, and results analysis to obtain the harmonic current and corrosion rate of the sample in interest.

Keywords

Corroison rate, Electrochemical Harmonic analysis

Rationale

5.1 This guide is based on the active corrosion of steel in acid solution in the laboratory, which may be extended to the application in the field for corrosion monitoring. Electrochemical Harmonic measurement and analysis is complimentary to other standard corrosion techniques, e.g., linear polarization resistance, electrochemical impedance and electrochemical noise et.al. Electrochemical Harmonic measurement and analysis is a non-linear technique. 5.2 This guide is practical for the measurement and analysis of corrosion rate without knowledge of Tafel constants. This is a major advantage over linear polarization resistance (LPR) measurement, since Tafel slopes can be obtained simultaneously from HA, together with corrosion currents. 5.3 Corrosion rate with HA is used to predict metal lifetime, materials selection and evaluation on corrosion resistance, optimize metal replacement, maintenance, or repairs to maximize profits. 5.4 Electrochemical Harmonic measurement and analysis may be employed for a determination and evaluation on the corrosion rate of metal with a protection of cathodic protection, inhibitor. 5.5 The corrosion rate measurements introduced in this guide can be done rapidly. Measurement time depends on the applied frequency, acquisition frequency, and the desired size of dataset. When applied frequency, acquisition frequency and measurement cycles are set to be 1 Hz, 20 Hz, and 103 Hz respectively, for example, the measurement can be finished in 103 seconds to obtain as many as 2,060 data points. Reliable corrosion rate can be acquired from 2,048 of the obtained 2,060 data points. 5.6 This guide is intended for conducting corrosion rate measurements for an active corrosion system in the laboratory. When the real-world problems are not identical to the lab experimental environment, the results from this guide may not be accurate and only be used as a reference.

The title and scope are in draft form and are under development within this ASTM Committee.

Details

Developed by Subcommittee: G01.11

Committee: G01

Staff Manager: Krista Robbins

Work Item Status

Date Initiated: 04-27-2020

Technical Contact: John Zhang

Item: 001

Ballot: G01.11 (21-01)

Status: Negative Votes Need Resolution