Study of the Effect of GTAW Welding Process on Pitting Corrosion Resistance of Material UNS N06625 Based on ASTM G48 C

• Main Author: SEPTIAN CHESAR RAHARJA SUPUTERA (NIM : 13713028), GEDE
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27470
• Institution: Institut Teknologi Bandung

<p align="justify">Corrosion is a degradation phenomenon of metal because of reaction with the environtment. Corrosion is a natural phenomenon since metals naturally more stable in their oxides states. Pitting corrosion is one of many forms of corrosion. In the industrial worlds, materials tend to be exposed to such an extreme work environtment. This harsh environtment can be in a form of high working temperature or even low PH or high acidity work environtment, in other words corrosive works environtment. In order to anticipate materials failure because of corrosion, materials with high corrosion resistance is chosen. One of this materials is UNS N06625 or usually known as Inconel 625. But, industrial worlds often use a component with a humogous dimension that need a joining process such as welding to put it together. In this case, the study for the effect of welding process in material UNS N06625 need to be done. The test in this study done by doing the immersion test based on ASTM G48 C standard by doing the immersion test in four different temperature criteria which are 75oC, 80oC, 85oC, and 95oC. Data that can be acquired from this test are in the form of number of pit and pit depth. Data from each run on each temperature then compared among one another to get to know the effect of welding process in the corrosion resistance of material UNS N06625.On the sample that’ve been immersed with running temperature of 75oC there is no sign of corrosion that can be seen. In the other way, the sample that have been immersed in running test temperature of 95oC extremely corroded so the data cant be extracted. On the sample that immersed in running temperature of 80oC and 85oC the pit initiated on the Heat Affected Zone. The next step is to do a regression based calculation to calculate the conjunction between pit depth and test temperature which can be concluded as “pit depth increased along with temperature accretion”. By extrapolation of the grapf, the CPT valued on 75.47oC. Based on both visual and quantitative data, can be concluded that HAZ because of welding process decrease the pitting corrosion restance of material UNS N06625.<p align="justify">