Corrosion Resistance of Some Common Metals to Concentrated and 6% Solutions of Light Water Fire-Extinguishing Agent

摘要

A study was made concerning the corrosion resistance of a group of common construction metals that might come in contact with the fire-extinguishing agent known as LIGHT Water. The metals examined were exposed to concentrated Light Water material and to 6% solutions of Light WATER PREPARED WITH SEA water and with fresh water. Type 304 stainless steel and titanium were virtually unaffected by any of the liquids. Overall weight losses for type 6061 aluminum alloy were low, on the order of 2 milligrams per square decimeter per day (mdd). However, localized pitting was observed. Monel had losses of 5 mdd with the Light WATER CONCENTRATE) The copperbase metals immersed in the concentrate exhibited weight losses in the range of 10-13 mdd, while steel, lead, and zinc were in the 18-40 mdd range. The corrosive effect of 6% solutions prepared with fresh water was generally not different than with fresh water itself, except for the copper-base alloys. The 6% solutions prepared with sea water gave results generally not different than with sea water itself. A comparison of the Light Water concentrate test results with earlier tests conducted on protein-type foam concentrates shows the latter to be considerably more corrosive. The limits for corrosion as set forth in the proposed military specification for LIGHT Water fire-extinguishing concentrate are lower than those in the current federal specification for protein foam concentrate. (Author)