Monty Luke, Principal Metallurgist – Bureau Veritas Asset Integrity and Reliability Services Pty Ltd
It is over seventy years since the specifications of the neutral salt fog test were first defined by ASTM B117 in 1939. American Society of Testing and Materials method B117 is the standard salt fog environmental test used for accelerated corrosion testing of materials. ASTM B117 is the universal international salt fog test method and the conditions of the test have been widely written into many national standards and industry codes. The conditions of the B117 test method produce an environment containing a salt fog that reacts with exposed specimens. The salt fog method is commonly called salt spray or salt mist testing, however these names are a misnomer as the environment that exists in the test chamber is a strictly controlled salt fog. ASTM B117 formalised the details of the salt fog test in a reproducible format. Salt fog testing had existed in various forms from 1914, however the parameters of the ad-hoc test methods and procedures varied significantly and it was difficult to compare the results of salt fog testing from the variety of methods used by laboratories.