THE EFFECT OF MICROSTRUCTURAL CHANGES ON THE CORROSION RESISTANCE OF WELDED AISI 1036 STEEL IN CHLORIDE ENVIRONMENT

Authors: *Awheme O, Unueroh G.U, Onyekpe B.O

DOI Info: N/A

ABSTRACT

This work investigated the effect of annealing temperature on microstructural changes and corrosion resistance of welded medium carbon steel in chloride environment. The samples were machined into cylindrical pieces of 20 mm diameter and 40 mm length for un-welded samples of 24 pieces and 60 mm length for welding samples of 24 pieces. The medium carbon steel samples were annealed at varied temperature of 860 ^oC, 920 ^oC and 1000 ^oC with a soaking time of one hour while some were not annealed and served as controlled samples. The samples were immersed in 1M NaCl solution for 60 days. The annealing temperatures used in this study yielded different microstructures which in-turn possibly affected their susceptibility to corrosion. The result showed corrosion attack on the annealed steel, with the severity increasing with higher annealing temperature of the samples. The result showed that as the annealing temperatures increases, the cementite and ferrite grains are relatively segregated from each other for the welded samples than the un-welded samples resulting in an increasing corrosion attack. The annealed un-welded samples showed better corrosion resistance compared to the welded samples while the control (un-annealed) sample show better corrosion resistance compared to the annealed samples.

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