A comparative analysis of TIG and laser/laser hybrid welding techniques for thermal power plant boilers

Title : A comparative analysis of TIG and laser/laser hybrid welding techniques for thermal power plant boilers

Abstract:

In the quest for cost-effective power generation amidst environmental concerns, innovative solutions are imperative. Advanced Ultra-Super Critical (AUSC) boilers, leveraging nickel-based superalloys like Inconel 617, aim to enhance coal-based power plant efficiency. Traditional welding methods face challenges in fabricating these boilers, including distortion and residual stresses, compromising longevity. Single-pass laser welding, including Autogenous Laser Welding (ALW) and Laser-Arc Hybrid Welding (LHW), offer promising alternatives with reduced heat input and minimal distortion. However, welding of Inconel 617 presents challenges, such as liquation cracking and achieving through-thickness penetration. This study compares single-pass laser methods with conventional multi-pass TIG welding, addressing these challenges. Feasibility studies on Inconel 617 demonstrated the importance of optimizing processing parameters for defect-free welds with maximum joint efficiency. Results from microstructural analyses revealed liquation cracking mechanisms and the formation of eutectic structures in the Partially Melted Zone (PMZ). Efforts to enhance weldability led to the development of Adaptive Diode-Laser Welding (ADLW), ensuring full penetration welds without defects. Comparative analyses highlighted the superiority of single-pass laser-based techniques in controlling bead profile, distortion, and microstructural homogeneity over TIG welding. Tensile tests and corrosion studies underscored the advantages of laser methods in producing welds with higher joint efficiency and resistance to environmental degradation. Overall, single-pass laser welding techniques offer significant advancements over traditional TIG welding, making them preferable for fabricating high-performance boiler components in thermal power plants. 

Keywords: Laser/Laser-Hybrid welding, TIG, Inconel 617, Thick sections, Joint efficiency, Ultra Super Critical Boiler 

Biography:

Dr. Mohd Aqeel brings over 6 years of expertise in laser-based processing and advanced characterizations, specializing in steel, superalloy, and aluminum alloys for applications in thermal power plant boilers, automotive parts, and more. With a PhD focused on laser welding of superalloys, earned in 2022 from the University of Hyderabad, he served as a senior research fellow at the International Research Center for Powder Metallurgy and New Materials (ARCI) from 2017 to 2021. Proficient in statistical modeling and materials characterization techniques, Dr. Aqeel has published numerous articles in peer-reviewed journals and pioneered novel methods in laser welding, hardening, and sintering processes.