Roles of hydrogen in shielding gas for compensate heat input on dissimilar joints of stainless steel series 200 between AISI 201LN and 214 by GTAW

Abstract

Austenitic stainless steel type 200 series was developed for indoor work due to being inexpensive. It is useful for reducing production costs. In this present work, the roles of hydrogen in shielding gas for compensate heat input on dissimilar joints of stainless steel series 200 between AISI 201LN and 214 by GTAW process was investigated. The technique used in this study applied an hydrogen mixture in argon shielding gas to compensate for the depleted heat input when increasing welding speed at an acceptable maximum of 5% H + 95% Ar at a welding speed of 6 mm/sec. The results of this study are evaluated for the following aspects: weld bead shape completely melted together without filler metal and non-defect. Microstructure combine between the delta-ferrite and austenite matrix under FA solidification mode which delta-ferrite decreasing trend when increase welding speed paired with add hydrogen in argon. In addition, it was discovered that the chemical composition of base metal high move to low concentrated. While the micro-hardness has an upward according to the amount of increase hydrogen same as the tensile strength properties and percentage elongation. While the micro-hardness has an upward according to the amount of increase hydrogen same as the tensile strength properties and percentage elongation. The fracture of tensile occur adjacent to side 201LN. The pitting corrosion resistance depend on volume of delta-ferrite phase and initial pitted between delta-ferrite and austenite.