Mechanical and Metallurgical analysis of HSLA steel for Gas Tungsten Arc Welding with different shielding gases 2019-28-0069
The special designed HSLA (High Speed Low Alloy) Steel is most commonly used in Naval Steel Structures and aircraft structures due to its indigenous properties. The aim of this paper is used to investigate the effect of shielding gas in the Gas Tungsten Arc Welding process. The sheet plate of size 300mmx150mmx10mm is taken and welded by GTAW process using argon and helium on the shielding gas. DMR 249A plates are welded by GTAW by using helium and argon as shielding gas with a flow rate of 16 L/min, the interpass temperature is 140ᵒ C and the heat input is less than 1.2KJ/min which is maintained to get a balanced phases of α and γ where the impact toughness, Tensile and micro hardness was studied with different shielding gas and the metallurgical properties were analysed in the base metal, heat affected zones and weld zones. The sheets contain 1.9%Ti and 6.2% Ni and the weld beads were studied for both the type of shielding gases. The study reveals that for helium gas the penetration is higher and wider. The ferrite number was investigated for both type of shielding gases.