Investigation of the effect of nitriding process on microstructure and mechanical properties in joining AISI 304 L stainless steel materials with laser welding

In this thesis study titled "Investigation of the Effect of Nitriding Process on Microstructure and Mechanical Properties in Joining AISI 304L Stainless Steel Materials with Laser Welding", in which the nitriding process, which has a wide range of applications and provides many benefits, is discussed together with the welding process of austenitic stainless steels, the joining of austenitic stainless steels used in many fields such as automotive, aerospace, aviation, manufacturing, health, food and defense industries with laser welding and the effects of nitriding process on laser welding have been investigated. In the mechanical tests performed on AISI 304L austenitic stainless steel specimens joined by laser welding method at 3 different power parameters, it was observed that the optimum results occurred in the specimen joined with 1500 Watt power. After determining the optimum welding parameter, the samples were subjected to pre-weld and post-weld nitriding processes and the effects of nitriding on the welding process were investigated in terms of microstructure and mechanical properties. Tensile, bending and hardness tests were used to determine the mechanical properties of AISI 304L austenitic stainless steel materials subjected to laser welding and nitriding processes. The microstructural properties were interpreted with the help of images obtained from optical microscope and scanning electron microscope (SEM) examinations.