THE EFFECTS OF FILLER METAL VARIATION ON MICROSTRUCTURE AND HARDNESS DISTRIBUTION OF JOINING LOW CARBON STEEL WITH STAINLESS STEEL 304L USING GTAW PROCESS

• Main Author: Lukman Amrullah - (13713022), Rilwanu
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23992
• Institution: Institut Teknologi Bandung

Dissimilar welding has a wide application in industry to maintain the cost itself. However, dissimilar welding process has problems to be identified furthermore, i.e. macro segregation, unmixed composition in fusion boundary, and brittleness. In this research, dissimilar metals will be jointed with variations in filler metal as ER-316L, ER-309, and ER-308. The welding process was GTAW methods with argon as the shielding gas and single V-butt as joint design. The base metal is low carbon steel with 0,172%wt of carbon and stainless steel 304L (SS 304L). Next, a metallography is conducted to observe the microstructure of base metal, heat affected zone, and weld metal areas. The results shows that the microstructure of all weld metals consist 𝛿ferrite and Austenite. At the HAZ of SS 304L there is sensitization phenomena. Also, for the HAZ of low carbon steel consist a soft pearlit with a darkband in the fusion line. Then, a hardness test was conducted along the specimen. The results shows that the hardness of base metal are increasing in the HAZ compared to the base metal. This was caused by diffusion of elements and the difference in the microstructure.