采用电化学循环极化曲线、FeCl3溶液浸泡以及扫描电子显微镜(SEM)等方法,研究了表面喷丸对国产800合金管抗点腐蚀性能的影响。结果表明,喷丸处理后800合金管的耐点腐蚀性能降低。对电化学极化试验后的试样进行SEM观察,未喷丸管点蚀坑面积大,且较浅;而喷丸处理后800合金管点蚀坑面积小而深。相对于未喷丸管,喷丸处理后材料表面晶粒的细化、喷丸过程中所带来的残余应力及表面变粗糙可能是800合金喷丸管耐点蚀性能降低的原因。
The effect of surface shot peening on pitting corrosion resistance of Alloy 800 tube was investigated using electrochemical cyclic polarization curve, FeCl3 immersion and SEM observation. The results showed that the pitting corrosion resistance of the shot peened Alloy 800 tube was lower than that of the un-shot peened Alloy 800 tube. SEM observation found that the pits of Alloy 800 tube before shot peening were bigger in area and shallower in depth than those of Alloy 800 tube after shot peening. The decreased resistance to pitting corrosion of the shot peened Alloy 800 tube was mainly attributed to the reduction of the surface grain size, the residual stress and the increased surface roughness caused by shot peening technology.