Corrosion analysis of HSLA-80/Inconel-625 dissimilar weldments
Journal
Results in Engineering
Journal Volume
28
Start Page
108018
ISSN
25901230
Date Issued
2025-12
Author(s)
Abstract
HSLA-80 steel is commonly used in marine applications due to its superior strength, toughness, good weldability, and atmospheric corrosion resistance. Inconel-625 alloy, which exhibits outstanding corrosion resistance and high-temperature strength, is a preferred choice for pipes in highly corrosive environments. This study investigated the corrosion behavior of HSLA-80 and Inconel-625 dissimilar weldments fabricated by multi-pass fusion welding using an electrode with a composition similar to Inconel-625. HSLA-80 steel was composed of quasipolygonal ferrite. The heat-affected zone (HAZ) on HSLA-80 steel consisted of primary ferrite, bainite, and martensite/austenite constituents. Electrochemical tests in 0.6 M NaCl solution revealed that the corrosion susceptibility decreased in the order of HSLA-80 > fusion zone ≃ Inconel-625. Moreover, the HAZ of HSLA-80 steel and Inconel-625 had inferior corrosion resistance compared to their base metals. The dissimilar weldment underwent a corrosion rate of 212.8 mils per year (mpy) after 88 days of immersion in 0.6 M NaCl solution. The corrosion rate of the as-received HSLA-80 steel evaluated by polarization curves was 1.6 mpy. Consequently, the corrosion of the HSLA-80 HAZ was accelerated by macro- and micro-galvanic coupling effects.
Subjects
Corrosion
Galvanic coupling
High-strength low-alloy steel
Multi-pass fusion welding
Nickel-based superalloy
Publisher
Elsevier B.V.
Type
journal article