Browsing by Author "Kumar, Aswin S."

Now showing 1 - 2 of 2

Microstructural, mechanical, and thermal analysis of SS316L weldment for marine engineering application
(2023-07) Kumar, Aswin S.; Shukla, Amarish Kumar
A SS316L steel is known as a marine-grade material, which is frequently used in a shipbuilding structure and marine industries. In the present study, a shielded metal arc welding (SMAW) process was used for similar welding of SS316L steel plate with dimension of 60 mm x 60 mm x 2 mm. A two different electrode E316L-16 and E308L-16, welding currents of 70 A, 80 A and 90 A and constant voltages of 24 V has been used for weldment. The impact of electrodes and current on the microstructure and mechanical properties of welded specimens was thoroughly investigated. To evaluate the flaw in the fusion zone (FZ), a surface macrograph and microstructure were analysed using scanning electron microscopy (SEM). In order to study the surface characteristics and ascertain the elemental composition of the samples, energy dispersive spectroscopy (EDS) was used. The hardness tests have been carried out in the base, heat-affected zone, and fusion zone of the welded joint. Tensile tests were carried out to study the effect of heat input on the yield strength (Y.S), Ultimate tensile strength (UTS) and elongation of a welded sample. According to the microstructure results, as the heat input increases, the grain structure of the welded zone gets finer in comparison to the base material. A hardness and tensile result shows that the properties of electrode and applied current has an effect on the mechanical properties of the SMAW welded sample. The hardness of the fusion zone increases compared to base material. The hardness result shows that as the current increases from70 A to 80 A by using the electrode of E316L-16 the hardness increases from 214 HV to 223 HV while the hardness further decreases to 208 HV for 90 A. Similarly, for E308L-16 electrode the hardness increases from 190 HV to 218 HV, and further it decreases to 168 HV for the applying current of 70A, 80A and 90 A respectively. A tensile result shows that the UTS of the SMAW welded sample varies from 190 to 262 N/mm2 compared to base material, i.e., 565 N/mm2Furthermore, thermal analysis was performed using ANSYS software to look at the impact of heat input at various welding arc times and identify the temperature distribution on the plate across various regions. In addition, the effect of heat input on the microstructure behaviour were studied in detail. The current thesis has been broken into six chapters. The first chapter presents an overview of steel welding and its applications in numerous fields. It also emphasises the distinguishing feature of the SMAW welded 316L stainless steel. Chapter 2 discusses the literature on various stainless steel processing processes, as well as the reported literature on the properties of 316L ix stainless steel, such as microstructural, mechanical, and thermal analysis of steel using the ANSYS software tool, and their applications. This is followed by identifying gaps in the literature and developing targets for addressing the issues related with SMAW welded 316L stainless steel. The materials and procedures employed in the current study are described in Chapter 3. Furthermore, this chapter discusses the various characterization strategies used in the current work. SMAW welded 316L stainless steel results and discussion in Chapter 4. A detailed investigation on the influence of changing current and electrodes on the microstructure and mechanical properties of SMAW welded 316L stainless steel was also conducted. Furthermore, the ANSYS software tool was used to study the temperature distribution during the SMAW welded 316L stainless steel. The study's summary and results are detailed in Chapter 5. Finally, in Chapter 6, the future scope and additional possibilities of current research work on SMAW welded 316L stainless steel were thoroughly examined.
Microstructural, mechanical, and thermal analysis of SS316L weldment for marine engineering application /
(Springer Nature, 2023-11-16) Kumar, Aswin S.; Shukla, Amarish Kumar
SS316L steel is known as a marine-grade material, which is frequently used in shipbuilding structures and marine industries. In the present study, a shielded metal arc welding (SMAW) process was used for welding of SS316L steel plate by using electrode E316L-16 and E308L-16, welding currents of 70, 80 and 90 A and constant voltages of 24 V. The effect of process parameters on the microstructure and mechanical properties of the welded specimens in the fusion zone (FZ), heat-affected zone (HAZ) and at base has been analysed using scanning electron microscopy (SEM) and microhardness test. The results show that the mechanical properties of the SMAW welded sample are influenced by both electrode properties and applied current. The fusion zone hardness increases compared to the base material. The welded sample processed by using electrode E316L-16 and 80 A current exhibits the higher hardness i.e., 223 HV due to a combination of lower heat input, higher welding speed, and the presence of a fine grain structure compared to other welded sample. A tensile result shows that the Ultimate tensile strength (UTS) of the SMAW welded sample varies from 190 to 262 N/mm2 compared to a base material, i.e., 565 N/mm2. This drop in tensile strength in the welded joints is attributed to HAZ softening stemming from the formation of coarse-grained microstructures. Furthermore, thermal analysis utilizing ANSYS software was employed to assess the influence of heat input at different welding arc times and to map temperature distribution across various plate regions. The results indicate that reducing welding time leads to lower temperatures in the electrode samples, consistent with simulation outcomes. Additionally, variations in microstructure were evident across distinct plate regions. The impact of heat input on microstructural behaviour was further comprehensively examined.