Abstract

The NACE TM0208-2018 standard jar test is a widely used tool for measuring the efficacy of volatile corrosion inhibitor (VCI) packaging materials to provide off-contact corrosion protection of steel surfaces. However, while ever improving, the standard still lacks sufficient technical specification for some of the materials used during the test procedure, which likely contributes to inconsistent results observed both within and between laboratories. For example, the use of mineral spirits to clean the steel specimen surfaces is unique to the TM0208 standard, but no comment or requirement is made about which of the various types and grades of mineral spirits should be used. In this paper, we investigate how cleaning the steel specimen surfaces with different grades of mineral spirits impacts their corrosion protection by VCI chemistries. In addition, we further explore how changes in the temperature and duration of the mineral spirits bath, together with covering the bath during cleaning, impact the sensitivity of the steel surfaces to corrosion. Ultimately, we correlate corrosion sensitivity with surface energy as measured by the contact angle of water droplets deposited on the surface of the steel specimens after completion of the TM0208 test.

Introduction

The NACE TM0208-2018 Jar Test remains an industry-wide recognized standard for evaluating the vapor-inhibiting ability (VIA) of raw materials and finished products to provide off-contact corrosion protection of steel surfaces1. It is particularly useful for comparing the efficacy of different VCI chemistries, as well as for monitoring performance consistency between productions of VCI functionalized materials. However, ambiguity regarding technical specifications for select materials used in the test, together with the sensitivity of the test to relatively slight and often unintended deviations from specific steps, has led to inconsistent results not only between laboratories, but also between individuals within the same laboratory, thus reducing the utility of the NACE TM0208 standard1.

This content is only available via PDF.
You can access this article if you purchase or spend a download.