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Potential-pH Diagrams
THERMEXPERT - Potential-pH diagram generator

Intelligent Tools

POLEXPERT - Polarization Scan Artificial Neural Network Expert System

SEQEXPERT - Sequential Immersion Test Artificial Neural Network Expert System

CYLEXPERT - Rotating Cylinder Electrode Intelligent Rotation Rate Calculator

Corrosion Calculator

Corrosion Rate Calculator


Corrosion Economics Estimator

FINCALCULATOR - Corrosion Economic Calculator

TUTORIAL ON POLEXPERTTM AND THE CYCLIC POTENTIODYNAMIC POLARIZATION TECHNIQUE

David C. Silverman


Table of Contents

Introduction - What is POLEXPERT?
Using POLEXPERT - a step-by-step procedure
Overview-Cyclic Potentiodynamic Polarization Technique
  1. Background
  2. Generation of the Scan
Effects of Experimental and Environmental Variables
  1. Corrosion Potential
  2. Solution Resistance
  3. Scan Rate
  4. Point of Scan Reversal 		     Features Useful in Interpreting Scan
  1. Pitting and Repassivation Potentials
  2. Hysteresis
  3. Active-Passive Transition or "Passivation Potential
  4. Anodic-to-Cathodic Transition Potential
  5. Passive Current
  6. Additional Examples in Literature
POLEXPERT (the intelligent prediction tool)
Applying Tutorial Principles - Critique of ASTM F2129

Introduction - What is POLEXPERT?

POLEXPERT is an internet accessible intelligent tool composed of an artificial neural network linked to an expert system that captures the collectivecorrosionexperience. to provide qualitative guidance on interpretation of the cyclic potentiodynamic polarization scan in terms of propensity for crevice corrosion, pitting corrosion and general corrosion occurring in the system under examination.

POLEXPERT enables:
  1. predictions of these forms of corrosion from cyclic potentiodynamic polarization scans that are consistent with experience.
  2. confidence in interpreting the results so more rapid decisions can be made about potential material-environment interactions.
  3. self-checking of one’s interpretation against the expertise of the collective corrosion experience as captured by the artificial neural network.
  4. expertise to be readily available when a "living" expert is not available.
Use of this intelligent tool requires that the polarization scan be properly generated and the features needed be extracted correctly. One of the goals of this tutorial is to provide the necessary background to do so. This tutorial assumes that the user knows the mechanics of how to set up and operate the equipment to generate a cyclic polarization scan. This tutorial provides the following:
  • a step-by-step procedure for using POLEXPERT using a real-life example
  • a brief overview of the cyclic potentiodynamic polarization scan technique
  • information and guidance on several key experimental and environmental variables that are user defined and require careful consideration
  • the features that are extracted from the generated scans, features for running POLEXPERT.
  • application of the tutorial principles to a critique of a standardized procedure - ASTM F2129
To go to a particular topic, click on the active word colored in blue. Clicking on the word "Top" at the end of each section will return to the table of contents at the beginning of the tutorial.

Next Page: Using POLEXPERT - a step-by-step procedure

Return to Table of Contents



David C. Silverman, Ph.D. - Primary Consultant
E-Mail:     dcsilverman@argentumsolutions.com
Phone:     314-576-3586
Fax:         314-754-9825
Address:   The Argentum House
                14314 Strawbridge Ct.
                Chesterfield, MO 63017