Laboratory corrosion tests were conducted on aluminum, carbon steel, chromium, and chromium-nickel stainless steels to evaluate their suitability as constructional materials for storage, transport, and applicator tanks for “nitrogen” and “complete-mix” liquid fertilizers. Two types of corrosion tests were conducted: (1) Partial immersion of small specimens of each material in each fertilizer solution, and (2) Simulated service tests in which small tanks fabricated of each of the test materials were partially filled with each of the fertilizer solutions. The amount and type of corrosion was evaluated by weight-loss determinations, thickness changes, pitdepth measurements, and metallographic examinations.
The results of the corrosion tests showed that in the nitrogen fertilizer solutions aluminum and several chromium and chromium-nickel stainless steels, were not attacked while carbon steel was attacked. In the complete-mix fertilizer solutions, only the chromium-nickel stainless steels were not attacked while aluminum, carbon steel, and three chromium stainless steels were attacked.
Service tests are being considered on carbon steel and some of the stainless steels that had satisfactory corrosion resistance in the laboratory tests. 4.3.4
