WU Shaobin
,
R. J. Arsenault
,
I. R. Kramer Metallurgical Materials Laboratory
,
University of Maryland
,
USA.
材料科学技术（英）
Intergranular stress corrosion cracking (ISCC) of α-brass in neutral Mattsson's solution was found to be controlled by an unusual "W"-shaped galvanic cell whose cathode is the grain boundary oxide film (G.B.0. film) and surface film and the anode is fresh metal at the cracked tip on both sides of the G.B.0. film. Redox reactions involved in the cell have been proposed here. According to this mdel, initidtion of ISCC is caused by the rupturing of surface film along grain boundaries, thus forming a galvanic cell. Propagation of ISCC resulted from alternate advances of G.B.0. film and dissolution on both sides of G.B.0. film caused by the effect of electrochemical reaction. This work developed an effective approach to investigate the embrittlement process at the tip of the crack, by increasing the length of the embrittlement region through constant strain test and distinguishing the morphology and the nature of the corrosion products by optical microscopy and scanning electron microscopy (SEH).
关键词:
α-brass
,
null
,
null
,
null
