ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The difference in microstructures of the base metal (BM), weld metal (WM) andheat-affected zone (HAZ) in the weldment is one of the major reasons for the failure of the weldedequipments, which can be essentially attributed to the non-homogeneous corrosion occurredelectrochemically on the weldment. Therefore, it is necessary to explore the corrosion properties ofweldment. In this paper, the electrochemical behavior of SPV50Q steel weldment was investigated.The polarization curves of BM, WM and HAZ in 5wt.%NaCl-0.5wt.%HAc solution containing H2Swere measured by potentiodynamic polarization. Interface characterization was also conducted byelectrochemical impedance spectroscopy (EIS). The results show the anodic curves are almost sameregardless of various pH or H2S content, but the cathodic curves show some difference. Relativelylarge variation in corrosion current density (icorr) obtained by fitting technique exists among BM,WM and HAZ. icorr of WM and HAZ is larger than that of BM, and icorr of WM is maximum.According to EIS results, polarization resistance (Rp) increases in the orders of WM, HAZ and BM.It is concluded that WM and HAZ are less resistant to corrosion than BM, which can be correlatedto the premature failure of the weldment serviced in H2S-containing environment such as sulfidestress corrosion cracking (SSCC) and /or stress oriented hydrogen-induced cracking (SOHIC) etc
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/55/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.353-358.3026.pdf
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