Accession Number : ADA330483

Title :   Methodology Investigation: Steel Corrosion in Tropic Mangrove Forests.

Descriptive Note : Technical note Sep 73-May 74,

Corporate Author : ARMY TROPIC TEST CENTER APO MIAMI 34004

Personal Author(s) : Johnson, M. A. ; Down III, G. F.

PDF Url : ADA330483

Report Date : NOV 1975

Pagination or Media Count : 31

Abstract : USATTC in September 1973 exposed 1440 steel samples for 8 months at eight sites (seven mangrove and one coastal) throughout the Canal Zone. Objective was to determine the relative severity of selected mangrove swamps on the corrosion of steel. This study reports the degradation rates of steel samples as measured by tensile strength loss, ranks results by season, and statistically compares results from each exposure site. There were statistical differences between wet and dry season exposures and between Pacific and Atlantic mangrove sites. There was a high degree of correlation between tensile strength loss and conductivity of water runoff collected from mangroves at 5 given site. High conductivity was caused primarily by water soluble salts washed off the mangroves by rain. One site proved more severely corrosive in both seasons than all others. Salt concentrations in the leaves at the most severe site were three to 16 times greater. It appears that the increased severity in degradation at this site was more a function of exuded salt from the mangroves than salt spray from the ocean.

Descriptors :   *STEEL, *TROPICAL TESTS, TENSILE STRENGTH, CORROSION, SALTS, SPRAYS, SWAMPS, PANAMA, TROPICAL DETERIORATION.

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE