Characterization and optimization of maraging steel using laser welding process

Abstract

The maraging steel are well known for its ultra high strength owing to its yield strength which is more than 1400 MPa and are part of a set of advanced materials of interest for technological development, mostly for aeronautics and aerospace industry. High-quality toughness, fatigue resistance and adequate weldability are the prime properties required for the said applications. These steels are used in the aerospace industry as highstrength fasteners, engine casings, missiles, landing gear structures, among others. In present only a small number of research works of the process of laser welding of maraging steels and it is significant to study the feasibility of welding these steels. This research work is concentrated on the significance of heat input and post-weld aging performance at different temperatures on the laser welded maraging steel grade 250. This research work involves with investigations on maraging steel weldments done by laser welding with an argon shielding. Similar welding of maraging steel plates of 4mm thickness with 1.5 3.5and#956;m roughness using a 4kW maximum output continuous CO2 (TRUMPF TLC1005). Metallographic analyses like macrostructure, microstructure, scanning electron microscopy (SEM) with EDS and micro hardness and characterization were done to analyze weldment characteristics. The SEM image was taken using Carl Zeiss version machine in high vacuum mode. The XRD results were taken using D/Max Ultima III machine in continuous mode. The tensile test was carried out according to ASME Section IX standard. The micro hardness tests were carried out along the weld center transverse section using an HMV-2000 Vickers micro newline