Structure and Hardness Analysis of Inconel 625 Nickel Superalloy Welded by Tig Method

Abstract

The aim of the work was to determine the structure and hardness of the parent material, the heat affected zone and the weld in butt joints of thin sheets with a thickness of 1.0 mm made of Inconel 625 nickel superalloy welded by TIG (tungsten inert gas) method. Test joints were made with different linear welding energy in the range of 70 - 145 J/mm. The obtained welded joints were subjected to visual tested, macroscopic metallographic examinations, observations of the structure on a light microscope, observations of the structure in a scanning electron microscope and a hardness measurement. The geometrical parameters of the joints were also specified. Chemical composition of structural components of selected areas of the weld, heat affected zone and parent material was determined by surface and point X-ray microanalysis. The range of linear energy was determined in which joints of thin sheets made of the tested superalloys in laboratory conditions show the best quality.