SEDL / STP / STP1385-EB / STP12470S

Salt Spray Performance Evaluation: Proposed Image-Analysis-Based Test Method

Warburton, YJ
Research Associate and Research Fellow, Technology Group, Calgon Corporation, Pittsburgh, PA

Gibbon, DL
Research Associate and Research Fellow, Technology Group, Calgon Corporation, Pittsburgh, PA

Pages: 12    Published: Jan 2000

Download this paper for $25 PDF (196K)          View License Agreement
Abstract

ASTM Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments (D 1654-92) is the current industry standard. This standard assigns a number, from 0 to 10, to reflect the width of the paint delaminated as measured from a scribe line to the creepage front. At times when the width along the scribe is not uniform, it is difficult to apply this standard. The difficulty lies in the fact that the standard is attempting to describe a two-dimensional pattern with a linear parameter. A two-dimensional parameter should be more suitable, and delaminated area seemed to be an obvious choice. Image analysis is a powerful tool to aid in the evaluation of the proposed parameter. The results using percentage area correlate well and linearly with D 1654 ratings. Effects of scribe length, paint color, reproducibility, and operator-to-operator variance are also discussed.