Investigation of hot cracking susceptibility in Inconel 625 TIG welded specimen using liquid penetrant inspection

Inconel 625, a high-performance nickel-based superalloy, is widely utilized in aerospace, power generation, and chemical processing industries due to its superior mechanical strength and resistance to oxidation and corrosion at elevated temperatures. However, its susceptibility to hot cracking during Tungsten inert gas (TIG) welding presents significant challenges to weld quality and structural integrity. This study employs an L 9 Taguchi design of experiments (DOE) to systematically evaluate the influence of key welding parameters namely welding current, travel speed, electrode diameter and gas flowrate of TIG- welded Inconel 625. Surface defect detection is carried out using liquid penetrant testing (LPT) to identify and characterize hot cracking. The purpose is to create a predictive framework that can direct the choice of weld parameters to avoid hot cracking. This method could improve welding quality, lower experimental expenses, and offer a better understanding of the welded defects of inconel alloy. Sample number 8 have been recognized as the best parameter 120 amps current, welding speed of 220 mm/min, 3 mm electrode diameter and 20 L/min gas flow rate.