Effect of Input Heat of SMAW Process on Microstructure and Corrosion of Weld Metal API ۵L X۶۵ Steel Joints Coated with INCOLOY ۸۲۵ Superalloy

In this study, the effect of input heat of SMAW process on the microstructure and corrosion behavior of welded metal API ۵L X۶۵ steel joints coated with INCOLOY ۸۲۵ superalloy was investigated. Welding with input heat of ۱.۰۳, ۰.۹۹ and ۰.۹۴ kJ / mm was performed using E۷۰۱۸ filler metal by SMAW process. FESEM scanning light and electron microscopy was used to study the microstructure. Evaluation of corrosion behavior of weld metal was performed using TOEFL polarization test in ۳.۵% NaCl solution. The microstructural results showed that the needle ferrite in the weld metal microstructure decreased with increasing inlet heat. While the values of Wiedmann Statten ferrites are multifaceted and grain boundaries. It was found that increasing the inlet heat had a negative effect and reduced the corrosion resistance of the weld metal.

Keywords:

X۶۵ steel , corrosion , electrode ۷۰۱۸ , welding , SMAW Process , فولادX۶۵ , خوردگی , الکترود ۷۰۱۸ , جوشکاری , فرآیند SMAW