アルミニウム黄銅の応力腐食感受性に及ぼす添加元素の影響

抄録

The most cause of troubls of aluminium brass widely used for heat exchanger tubes in petroleum refining plant lies in its high susceptibility to stress corrosion cracking. Stress corrosion of Cu-Zn alloy has been investigated extensively, while little study has been made on that of Cu-Zn-Al alloy. Authors have studied the stress corrosion of Cu-Zn-Al ternary alloys and effects of additional element to the stress corrosion.
(1) Addition of silicon to aluminium brass remarkably lowers the alloy's susceptibility of the alloy to stress corrosion.
(2) Aluminium brass containing silicon does not greatly depart from plain aluminium brass in corrosion resistance to sea water and sulfide, and also in mechanical and physical properties.
(3) From the above-mentioned facts, it appears that, for heat exchanger tubes in petroleum refining plant, aluminium brass modified with silicon exceeds the customary aluminium brass in inhibiting stress corrosion failure. Besides, it does not seem to cause any other troubles in its use.
(4) Mechanism on how the addition of silicon affects the stress corrosion susceptibility has been studied. And it has been found that the mechanism is principally attributed to some chemical factors.