Investigation of Filler Material and Process Parameters on TIG welded AISI304 Austenitic Stainless Steel and AISI430 Ferritic Chromium Stainless Steel /
Uzair Ahmad
- 125p. Soft Copy 30cm
Welding is a versitile process of metal fabrication that fuses two of more materials for joining. The choice of welding parameters is a crutial element in planning stage for producing quality joints. Tungsten Inert Gas (TIG) welding is a high precision welding technique that uses a non-consumable tungsten electrode in the presence of shielding gas to produce clean welds. The TIG welding is applicable on variety of metal alloys due to its controlled parameters ability. The paramount work of this research was to investigate the TIG welding of distinct stainless-steel grades austenitic stainless steel AISI 304 and Ferritic Chromium Stainless Steel AISI 430, and analyze the impact of providing distinct nature of filler materials with controlled welding parameters. The TIG welding is inflenced by extensive input parameters like welding current, weld speed, arc voltage, shielding gas flow rate, temperature, and presence of filler material. Preformance impacting factors used for this study are welding current, filler diameter and shielding Gas flow rate. A comparative analysis of two different filler materials ER308L and ER410 is produced. ER308L filler wire produces good mechanical properties when welding disticts metals with the AISI 304 and AISI 316 due to its strong austenitic weld pool. The utility of ER410 filler rod in welding AISI 430 material gives strong mechanical leverage over ER308L filler. To test the mechanical behaviour of AISI 304 and AISI430 welded joint, the experiment is devided into two sections of ER308L and AISI430 filler based welds. Each set of experiments were designed using Taguchi L9 DOE orthognal array. The depedency of mechanical properties, tensile strength, flexural strength and microsctructural hardness was evaluated using analysis of verience (ANOVA) method. Universal Testing Machine (UTM) machine was used in conducting tensile and three point bend tests for each sample produced on fiber laser cutting machine. Rockwell hardness tests (RHT) were conducted according to ASTM E18 on B00IW5LTBY Gowegroup Rockwell hardness apparatus. The Optical microscope was utilized for visual analysis of fusion zone, BM and HAZ of each sample. Tensile tested samples were analyzed under electron microscope for observation of defect like porosity, penetration of weld, micro cracks, and fusion of metals.