engleski

Corrosion failure and microstructure analysis of AISI 316L stainless steels for ship pipeline before and after welding

In the present study the corrosion behavior of AISI 316L stainless steel samples, taken from different parts of the ship pipeline, were investigated in chloride solutions. Research was conducted using gravimetric tests in 6 wt.% ferric chloride solution as well as cyclic potentiodynamic polarization measurements in 0.5 mol dm-3 NaCl solution. Additionally, the mechanism of corrosion attack developed on the steel surface was analyzed by optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. Microstructure analysis was performed before and after corrosion testing. The results showed that the lowest corrosion damage occurred on the base metal sample while the sample of interface of the weld metal/heat affected zone (WM/HAZ) had severe pitting damages. Inclusions were observed at the interface of the WM/HAZ, and this can be the main reason for pitting initiation.

austenitic stainless steel ; welding ; pipeline failures ; corrosion ; cyclic polarization ; microstructure

Glavni autor: Stjepan Kožuh, Mirko Gojić