Friction welding of AISI 304: effect of friction time on micro-structure, micro-hardness and tension-compression properties

Abstract

During direct drive friction welding could relatively predicting the micro-structural and mechanical properties of friction-welded joints by controlling the welding conditions; friction time is an important coefficient that effects on these properties, present study focused on the effect of that time on micro-structural and mechanical phenomena during that process. The process achieved in different friction time, while welding joints investigated by macroscope, microstructure, scanning electron microscope, tensile, compression and micro-hardness tests. The micro-hardness tests were performd along the interface and axial direction. Thus, the tensile tests carried out on the standardized test piece with effective diameter of 6 mm and compression tests were extracted at welded center in three angles of 0°, 45° and 90° with test specimen of 4 mm diameter and 6.5 mm length. The results showed that with increasing friction time could be found hard zone at the interface of welded joint because of extended of high plastically deformation zone, which will responsible on decreasing some useful mechanical properties such as ultimate tensile strength and yield compression strength. However, tensile fracture position occurred adjacent to the interface at the thermo-mechanical deformation zone in the rotating side for all welding pieces, where the micro-hardness attenuated at that region.

Archives of Metallurgy and Materials

“…Conversely, after forge application, the value of micro-hardness increases at the center of welding, as mentioned in the microstructural study, the thermo-plastic deformation and dynamic recrystallization responsible on grain refinement in the interface. strain hardening [9] and high friction pressure [13] are most important conditions influence on the elevation of the micro-hardness, particularly, at the welding interface. While, micro-hardness attenuation in the adjacent regions after forge is due to enough amount of heat input which causes grains growth.…”

“…it has 3 phases AC with 3.5 kw power of motor, 0-3000 rpm range of speed and 300 MPa maximum pressure. Chosen friction welding conditions gathered in TAbLe 3, the conditions were selected according to the dimensions of test piece, metal nature and depending on the earlier studies [1,3,9,11,15]. Welding temperature was verified in two types of thermometer (Fig.…”

“…This process has several advantages: short time, low input energy, below melting temperature and high reproducibility [2][3]. Principally, it consists many processes: inertia [4], orbital [5], linear [6], friction stir [7][8] and direct drive friction welding (DDFW) [9]. in application, friction stir and DDFW are the most versatile.…”

“…While, DDFW generates heat by increasing temperature of the interface between the two pieces in contact under influence of axial pressure and rotation speed, first piece held in the stationary part and second piece chucked in the rotating part. The two pieces still in contact of each other until the rotation stops suddenly, this period is called friction phase, followed by pressure elevation for certain of time to consolidate welding joint and finish the process, this interval of time is known as forge phase [9].…”

Improvement of Corrosion Resistance of Stainless Steel Welded Joint Using a Nanostructured Oxide Layer

“…Overall, type 304 SS exhibits superb mechanical strength [9,10], high ductility [10], and high corrosion [1,8,11,12] and heat resistance [13], making it highly versatile. Due to this versatility, the SS is used in industries involved in mining, petroleum processing, metal processing, nuclear engineering, underwater construction and additive manufacturing [14,15]. However, all these applications require some degree of welding, diminishing the corrosion resistance of the SS.…”