The Effects of pH on the Corrosion Characteristics in Dissimilar Friction Welded Zone of IN713LC-SCM440

J. Ocean Eng. Technol. 2005;19(2):53-59.

JO SANG-KEUN;KONG YU-SIK;KIM YOUNG-DAE;

Dept. of Mechanical Engineering, Graduate School of Pukyong National University;School of Mechanical Engineering, Pukyong National University;School of Mechanical Engineering, Pukyong National University;

IN713LC-SCM440 이종재 마찰용접부의 부식특성에 미치는 pH의 영향

조상근;공유식;김영대;

부경대학교 대학원 기계공학과;부경대학교 기계공학부;부경대학교 기계공학부;

Keywords: Friction Welding, Torsional Stress Corrosion Test, Galvanic Corrosion, Corrosion Rate, Relative Electrode Potential, Relative Corrosion Current, Corrosion Pattern

핵심용어: 마찰용접, 비틀림응력부식실험, 갈바닉부식, 부식속도, 상대전극전위, 상대부식전류, 부식양식

Abstract

The effect of pH on the corrosion characteristics in the dissimilar friction welded zone of IN713LC-SCM440 in the loaded torsional stress was studied. The corrosion experiment was performed for 120 hours on the specimens with five steps of pH. The surface corrosion pattern of the SCM440 area showed global corrosion and narrow pitting, which was caused by galvanic corrosion between friction welded IN713LC and SCM440, but corrosion did not proceeded from the IN713LC area. The average relative electrode potential gradually tends to decrease with the elapse of the immersion time in the acidity area. The average corrosion current also gradually tend to decrease The corrosion rate showed a larger value when the average relative electrode potential was higher and the average relative current was lower. The corrosion rate showed a larger value when the average relative electrode potential was higher in the acidity area, and it showed large when the average relative electrode potential was lower in the alkalinity area.