PREVENTION OF LIQUID AMMONIA STORAGE TANK FROM STRESS CORROSION CRACKING

摘要

PURPOSE:To prevent the tank from the stress corrosion cracking easily and economically by forming a zinc coating in a specific range both sides of a weld line, a jig impression and existing jig in an inner surface of the liquid ammonia storage tank. CONSTITUTION:In the inner surface of the tank constituting material of the liquid ammonia storage tank, the zinc coating is formed in a range of 5-60cm from the center of the weld line to one side on both sides of the weld line, in a range of 3- 40cm from an inside or a periphery of the jig impression when the jig impression is formed and in a range of 3-40cm from a periphery of the jig when the jig is present. The thickness of the zinc coating is about 60-500g/m2 and, even if the zinc coating is limited to only lower portion below an ordinary liquid level of the tank, the effect for preventing stress corrosion cracking is sufficient.