Welding Metallurgy of

Stainless steel is a widely used material in various industries such as aerospace, chemical processing and transportation. Tungsten Inert Gas (TIG) or Gas Tungsten Arc Welding (GTAW) process is ext...

A novel perception toward welding of stainless steel by activated TIG welding: a review

This work investigates the microstructure and corrosion characteristics of an Inconel 625 weld cladding deposited by the electroslag welding (ESW) process with a single layer on an ASTM A516 Gr. 70 steel plate with a heat input of 11.7 kJ/mm. Microhardness testing, metallographic examination and corrosion tests were performed on samples removed at 1 and 3 mm parallel to the fusion line. Metallographic characterization was performed by optical and scanning electron microscopy. Energy dispersive spectrometry was also used to evaluate the composition of the secondary phases. Cyclic polarization tests in 3.5% NaCl solution were performed at the same position as the metallographic examinations. Immersion corrosion tests following the ASTM G 48 Method A were also conducted. Equivalent corrosion results were obtained at both positions due to the austenitic microstructure of the weld metal containing a very low amount of secondary phases. The results of the corrosion tests were consistent with the microstructure and low dilution and remained at a level acceptable for structures. Thus, the ESW process may be considered an alternative for overlay welding with Inconel 625 with reduced thicknesses, because good results were observed at only 1.0 mm from the fusion line, and this could represent a significant cost reduction.

Microstructure and corrosion properties of single layer Inconel 625 weld cladding obtained by the electroslag welding process

Role of A-TIG process in Joining of Martensitic and Austenitic Steels for Ultra-Supercritical Power Plants -A State of the Art Review

This article presents the welding process parameter optimization for activated tungsten inert gas welding of a 6.5 mm thick Inconel 625 plate. The experimental design L25 has been undertaken to obtain optimal parameters for inputs, including welding current, torch travel speed and arc gap on penetration depth. Welding cross-sectional area, microhardness and welds bead width and bead height have been investigated using various mathematical optimization tools like grey relational analysis (GRA) and Technique for Order Preference by Similarity to Ideal Solution. ANOVA has been used to identify each input parameter’s significance. Through bead on trial experimentation, the computed output results of GRA provided the following recommended settings such as 300 A welding current, 90 mm/min Torch travel speed and 5 mm Arc gap as the best optimized parameters. The optimized samples were examined by a scanning electron microscope with energy dispersive X-Ray spectroscopy techniques for a comprehensive study on the laves phase at the interdendritic regions of the weld zone. X-ray diffraction analysis revealed that the major element present in the weld zone was Ni due to which activated flux quickened the solidification rate and reduced laves phase formation.

Systematic Welding Process Parameter Optimization in Activated Tungsten Inert Gas (A-TIG) Welding of Inconel 625

The pulsed gas tungsten arc welding with hot wire was used to clad Inconel 625 on the surface of X65 steel. The influences of welding current in horizontal welding position on the dilution, in furt...

Kunyang Song

Papers

Welding current influences on Inconel 625/X65 cladding interface