Determination of the sensitized zone extension in welded AISI 304 stainless steel using non-destructive electrochemical techniques
- 作者：Pedro de Lima-Neto ; Jesualdo P. Farias ; Luis Flá ; vio G. Herculano ; Hé ; lio C. de Mir ; a ; Walney S. Araú ; jo ; Jean-Baptiste Jorcin ; Nadine Pé ; bè ; re
- 关键词：A. Stainless steel ; B. EIS ; B. SEM ; C. Welding ; C. Intergranular corrosion
- 刊名：Corrosion Science
- 出版年：2008
- 期刊代码：28_0010938x
- 类别：ch
- 出版时间：April 2008
- 卷：50
- 期：4
- 页码：1149-1155
- 文件大小：1254 K
摘要
Extension of sensitized zone (SZ) in welded AISI 304 stainless steel was determined by two non-destructive electrochemical tests: double loop electrochemical potentiokinetic reactivation technique (DLEPR) and local electrochemical impedance spectroscopy (LEIS). Welding was carried out using the shielded metal arc with two selected welding energies: the first one (0.7 kJ mm−1) does not promote the sensitization of the 304 steel and it constitutes the reference sample and the second one (2.2 kJ mm−1) which leads to the precipitation of chromium carbides in the grain boundaries after the welding process. The non-destructive DLEPR and LEIS tests allowed the length of the SZ to be determined and a good agreement between the two techniques and the microstructure of the two welded samples was shown. The presence of an inductive loop on the local impedance diagrams seems to reflect a galvanic coupling between the weld string (anode) and the welded stainless steel plates (cathode) which will be very prejudicial to a good corrosion resistance of the welded system. The results showed that the two electrochemical tests could be applied in practical cases in industrial field.