Volume 4, Issue 6 (November 1976)
Corrosion and Dezincification of Brasses in Water
A study of the corrosion and, specifically, dezincification resistance of several commercial and proprietary red, semi-red, and yellow brasses in water is reported. The primary variables were the composition, method of manufacture, and thermomechanical history of the metal, the composition and temperature of the water, and the exposure time. Two types of tests were utilized: (1) static immersion tests of 17 days' duration in a solution specially formulated to reveal dezincification attack and (2) static immersion tests of one year's duration in a synthesized, aggressive, potable water at room and elevated temperatures. The principal findings were that sand-cast red and semi-red brasses (CDA Alloys 836, 844, and 848) exhibited excellent dezincification resistance, as did the newly developed yellow brasses. The CDA 377 forging brass had poor dezincification resistance. Lead pitting can occur in long time exposure to water on machined surfaces of cast leaded red and leaded semi-red brasses and in free cutting brass.