Abstract
The current study investigates the metallurgical, mechanical properties and weld morphology of AH36 marine grade steel (with a thickness of 8 mm) by activated-tungsten inert gas (A-TIG) butt joints, with the application of different fluxes (MoO3, V2O5, and duplex of MoO3 and V2O5) at various process parameters. The welding speed was kept constant at 120 mm/min, and current varied from 160 A to 220 A uniformly to optimise process parameters to achieve desired mechanical properties, weld morphology, and lowest possible heat input. The study also focused on comparing tensile strength, impact strength, and microhardness, heat input during welding, weld bead depth and width between conventional TIG welding and activated flux TIG welding processes at various operation parameters. Tensile results reported that fracture occurs at the base region in ordinary TIG welding and the activated tungsten inert gas welding process. It was noticed that a higher depth to width ratio attained MoO3 and V2O5 duplex flux coated weldments. There is evidence that the depth of weld joints is enhanced because of stable arc, Marangoni effect, and arc constriction. Microhardness results reported that the fusion zone has a higher microhardness in the activated tungsten inert gas welding than the ordinary TIG welding. It was concluded that out of all fluxes, MoO3 and V2O5 duplex flux coating produce better butt welds of AH36 steel.
Highlights
The shipbuilding, seaward, and structural based components utilised high strength low alloy steels (HSLA) for manufacturing parts
The overall goal of this project is to activated-tungsten inert gas (A-Tungsten Inert Gas (TIG)) welding of AH-36 marine-grade steel and investigate relevant weld morphology, as well as mechanical properties of the A-TIG welded joints, such as tensile strength, microhardness, and impact strength experimentally
It has been observed that tensile strength without flux coating of GTWA was nearer to the parent material 453MPa
Summary
The shipbuilding, seaward, and structural based components utilised high strength low alloy steels (HSLA) for manufacturing parts. The steel exhibits an equiaxed very fine-grain ferrite microstructure accompanied by excellent weldability and its tensile property Most of these kinds of steel comprise Fe with roughly 0.2% C and grain refining elements such as Ca, Zr, and Sn. Most of these kinds of steel comprise Fe with roughly 0.2% C and grain refining elements such as Ca, Zr, and Sn These provide upgraded protection from the weak crack and other required quality levels of steel obtained from other alloying elements like Si, Nb, Mn, and Mo. The American Bureau of Shipping utilised AH36 steel to manufacture transportation goods, vessels, and structural components because of its versatility characteristics [1],[2]. During TIG welding, the tungsten electrode, electric arc, and molten metal had been protected by shielded gas of argon or helium. The TIG welding process’s powerlessness became restricted to weld joints depth up to 3 mm only [3],[4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
