Patent ID: 7585677

Claim:
A method of evaluating the corrosion resistance of a material in an ammonium bisulfide environment, which comprises the steps of: simulating, using physical property software, a relationship between a pressure and a concentration of an ammonium bisulfide test solution in advance to calculate a desired pressure of said test solution needed in the corrosion resistance evaluation; preparing a wet ammonium solution containing hydrazine; preparing a filling apparatus comprising an autoclave test tank with a pressure regulator; setting a test piece in the autoclave test tank; injecting the wet ammonium solution containing hydrazine into the autoclave test tank; passing hydrogen sulfide gas into said autoclave test tank to prepare said ammonium bisulfide test solution and maintaining the autoclave test tank at said desired pressure; heating the autoclave test tank at a desired temperature; holding the desired temperature of the autoclave test tank and checking the internal pressure of the autoclave; measuring the temperature of the autoclave test tank; determining the ammonium bisulfide concentration from the internal pressure; and measuring the change in the weight of the test piece.