Study of the Effect of Water jet cutting, Laser cutting, TIG Welding, and MIG Welding on the Mechanical and chemical Properties of AISI 304 Stainless Steel Samples

Abdulkarim Alzahougi¹              RabiaHadi Elhag²

Abstract:

This study aims to identify optimal process criteria for obtaining the best weld joint and the effect of this on the properties of the metal, by comparing two welding techniques for the samples of 304 Stainless steel, after cutting them by using the water and laser cutting techniques, cut 28 samples of the metal with a thickness of 5 mm, half of them by water Jet cutting and the remaining half were cut by laser cutting, 9 samples were welded by TIG technique and another 9 by laser welding with different welding parameters. The effect of these variables on the quality of the weld as well as on the mechanical properties of the metal were studied to determine the best operation condition and cutting that lead to the best weld joint, the hardness and ultimate tensile strength of base metal, heat affect zone and weld metal were measured at each welding parameters.The study revealed that water cutting results in terms of cutting quality was the best, also showed both hardness and tensile strength increased with increasing the current up to 70 A, then reduced at higher values. This increase was also observed when the amount of SC gas increased to 9, conversely found a direct relationship between the hardness, amount of PS gas and tensile strength, the samples were cutting by water jet showed the highest hardness and tensile strength in the heat affect zone, while the highest values were in the weld metal for laser cutting. In the case of welding the metal, the highest hardness was at voltage of 17 volts and the highest tensile strength value at value of 18 volts for laser cut samples.

Key words: water cut, laser cat, TIG Welding, MIG Welding Hardness test and Tensile strength test.