Summary
The reactive metals, titanium, zirconium, tantalum, and their alloys, are used successfully in numerous specialty applications in the chemical process industries where resistance to aggressive environments is required. These metals are classified as “reactive” because of the ease with which they react with hydrogen and oxygen. They are resistant to many corrosive services because the oxide films which form readily in air are protective and self-repairing. However, beneath the oxide layer the reactive metals remain highly reactive. Finely divided titanium or zirconium can be readily ignited in air. There are a number of cases where these alloys have been ignited by flame cutting or similar operations. Under some conditions corrosion products may ignite spontaneously in air. These properties have occasionally caused spectacular and well publicized events.
This report summarizes and analyzes the known case histories. It is intended to help avoid such events, while encouraging continued use of those alloys in the numerous environments where they can be used safely and economically.
