Investigation of microstructure and microhardness properties of Nd: YAG laser welded galvanized steel plates

Modern industry has discovered many uses for stainless steel because of its excellent mechanical and physical qualities, outstanding resistance to oxidation and corrosion, hot and cold workability, and superior weldability. The development of lightweight, cost-effective materials is being driven by technological advances. Thus, in order to satisfy Industry 4.0 criteria, additional materials that are resistant to corrosion and oxidation are required. Utilizing galvanization has extended the lifespan of materials used in the chemical, automotive, and white goods sectors, among other industries. Zinc coating, often known as galvanizing, is one technique for surface protection. It is inevitable that welding techniques will become widely used in component manufacturing. Several welding techniques may be used on galvanized materials, but they also come with several drawbacks for the joined samples, including flaws, porosities, and solidification fissures. As a result, the popularity of laser welding (LW) has steadily risen. In the current research, Nd-YAG laser welding was used to combine 2mm thick sheet-galvanized steel sheets. Microhardness tests were used to assess welded samples to determine their mechanical characteristics. Experimental results showed that the microhardness of the welded area was higher than that of the base metal. The microstructure of the welded samples was also examined using SEM and EDS mapping to look for flaws in the base metal, coating, welded area, and HAZ. SEM images revealed that a martensite structure was formed in the weld area, and a smooth joining process was achieved.