摘要
研究了冷却速率对Al-Zn-Mg-Cu合金厚板剥落腐蚀性能的影响。结果表明,降低冷却速率,合金的剥落腐蚀性能随之下降,腐蚀等级由EB级变成ED级,腐蚀电极电位更负,电流密度增加,极化电阻减小且与冷却速率呈线性关系。冷却的速率降低导致晶界析出相覆盖率增大,晶界析出相的Cu含量降低和晶界无沉淀析出带宽化是剥落腐蚀性能下降的主要原因。
The effect of cooling rate on exfoliation corrosion of Al-Zn-Mg-Cu alloy thick plate was inves- tigated by polarization curve test, corrosion immersion test and end quench method. The results show that with cooling rate deceasing, the resistance to exfoliation corrosion decreased, from EB to ED, the corrosion potential decreased, the corrosion current density increased, and the polarization resistance de- creased. There is a linear relationship between polarization resistance and cooling rate. The decreasing of cooling rate results in the higher coverage ratio and lower copper content of the grain boundary precipi- tates, wider precipitate free zone near grain boundaries, which are the primarily responsible for lower re- sistance to exfoliation corrosion.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2013年第3期259-266,共8页
Chinese Journal of Materials Research
基金
国家重点基础研究发展计划2012CB619500资助项目~~
关键词
材料失效与保护
铝合金
剥落腐蚀
晶界析出相
无沉淀析出带
materials failure and protection, aluminum alloy, exfoliation corrosion, grain boundary pre-cipitates, precipitate free zone
