【摘要】 经历相同的服役环境和时间,黄铜HSn70-1A呈现不同的腐蚀现象:一种试样宏观上无明显腐蚀,而另一种试样则发生直径约1mm的穿孔腐蚀.分析表明,腐蚀状况有如此差异的主要原因在于两者的显微组织不同.无明显宏观腐蚀的试样晶粒相对粗大但均匀;而发生穿孔的试样.晶粒相对细小,并有大小不一的情况.这源于加工过程中变形不均匀,最终形成相差悬殊的晶粒状态,使得材料中不可避免地存留有残余应力.因此,腐蚀状况表明合金显微组织决定其局部腐蚀的敏感性.更多还原

【Abstract】 It is observed that HSn70-lA brass tubes(70:30) showed different corrosion behavior under the same service condition for the same time period due to its perculiar microstructure: for example,one showed no local corrosion and the other showed perforation of 1 mm in diameter serviced in fresh water for several months.It was found that the former had larger grians but rather uniform in size.The latter showed a microstructure with finer grains but containing certain larger grains.This kind of microstructure possesses very strong sensitivity for intergranual corrosion and stress corrosion when the alloy tube immersed in fresh water.更多还原