Abstract
Rust inhibitors should be selected with reference to the type of service in which they will be used. Many inhibitors which give satisfactory results under mild rusting conditions fail to provide useful protection under more severe conditions. Laboratory testing programs should be designed, therefore, to reproduce as closely as possible the conditions of actual practice.
Rust inhibitor test methods are discussed in relation to three general classes of service, corresponding to flowing, static, and condensation conditions. A new rust inhibitor testing procedure, based on the Indiana Conductometric Test, provides quantitative measurements of very low corrosion rates under carefully controlled conditions. Small differences in the performance of good rust inhibitors have been detected by this method.
The choice of general type of rust inhibitor (aqueous- or oil-soluble) as well as the particular compound to be used in any case, should be based on the results of selected quantitative laboratory tests, correlation with field tests and experience, and an analysis of relative cost data for useful inhibitors on an equal protection basis. An economic evaluation of possible alternate procedures for obtaining any desired degree of rust protection also should be made. 5.8.1.
