Investigators: Mark R. Stoudt, Richard E. Ricker, James L. Fink, and James F. Dante

Technical Description:

It has been determined that one of the most commonly used fire suppressants, halon, has sufficient ozone depleting potential that its production and use should be restricted. Non- ozone depleting alternatives to halon could be sufficiently corrosive to cause corrosion failure of fire suppressant storage and distribution systems. The objective of this project is to assist industry's transition from halon to other non-ozone depleting fire suppressants by evaluating the corrosivity of chemical compounds that could be used for fire suppression in place of halon.

Technical Objectives:

• To evaluate the propensity for failure of typical storage system alloys as a result of exposure to any one of the replacement candidate chemicals during service or after deployment.

• To determine the corrosion rates over a broad range of conditions as well as evaluate the susceptibility the alloys to stress corrosion cracking, pitting and crevice corrosion.

Anticipated Outcome:

• If a suitable replacement can be identified for halon 1301, it will significantly reduce the rate of stratospheric ozone depletion without compromising public safety.

• Identification of chemical compounds that should not be developed further as a replacement for halon will save industry and government agencies considerable time and money by allowing them to focus on usable alternatives.

Accomplishments for FY 1995:

• Completed long term testing in each of the halon alternatives selected for further evaluation.

• Performed in-depth statistical analyses of the data from immersion experiments and incorporated those into a predictive model. The model can be used to estimate the corrosion rates in these chemicals.

• Two papers reporting the results of this work were completed and submitted for publication.

Impacts and Technical Highlights:

• Since the corrosion behaviors of these chemicals are not well known, the data and predictive models produced by these evaluations will be of considerable value to the Air Force, the Federal Aviation Administration (FAA), the Envirmental Protection Agency (EPA) and to aircraft system designers as halon 1301 is scheduled to be completely removed from service in the next few years.

• Several compounds which were being considered for development as an alternative to halon have been eliminated from consideration allowing industry to focus on viable candidates, thereby reducing their costs for developing halon alternatives.

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Last modified: Mon Jan 06 09:46:15 1997 Metallurgy Webmeister