Dezincification is still a frequent cause of failure of brass. Though inhibited Admiralty brass and Muntz metal may occasionally dezincify in such severe services as feed water deaerators, in an overwhelming majority of the cases dezincified specimens are not inhibited. As a means of identifying the materials especially subject to dezincification, a test solution was devised to differentiate between the resistant and susceptible materials.
The test solution used successfully since 1943 is the following:
The solution may be used as a spot test medium. Used in this fashion, it is applied to a freshly abraded surface. An alternate is to dip the tube or other object in the solution. At room temperature, thirty-second exposure is enough to give a clear indication. Uninhibited brass becomes coated with metallic copper or a pinkish-gray deposit. Inhibited brass (arsenic, phosphorus, or antimony) becomes coated with a dark gray to black film. Until one becomes...
