Effect Of Welding Speed Research Articles

Effect of work material combination and welding speed in dissimilar friction stir welding of aluminium to steel

Effect of welding speed on strength and ductility of the friction stir butt welded assemblies formed with two different combinations of sheet metals viz. AA 1100 – AISI 304 and AA 7075 – AISI 304 was investigated. The experiments were conducted on a 30 kN CNC friction stir welding machine with the help of a tool made of H13 steel having a tapered cylindrical pin. Finite element simulation of approximated heat transfer model was conducted to check the effect of tool offset on distribution of temperature in aluminium and steel. Ultimate tensile strength and percentage elongation at break of weld metals decreased with the rise of welding speed. Microstructural characterization was carried out to investigate the reasons of poor joint efficiency obtained.

Effect of laser welding speed on the weld quality of a 5A06 aluminum alloy

Abstract Laser butt welding was carried out for the joining of 5A06 aluminum alloy sheet by using 6 KW fiber laser. The effect of welding speed on the surface morphology, microstructure, micro-hardness, tensile strength and porosity were studied by means of optical microscopy (OM), a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), a Vickers hardness tester and a universal mechanical tensile test. The results show that the weld macro morphology tends to be smooth and the surface defects are reduced with an increase in welding speed. The heat-affected zone was very small due to the large cooling rate. The columnar dendrites grow from the fusion line along the direction of the temperature gradient. The microstructure of the weld zone was in the form of equiaxed grains. The micro-hardness of the weld was lower than that of the base material. The micro-hardness and the tensile strength were gradually increased with an increase in welding speed. When the welding speed is 12 mm × s−1, the micro-hardness and the tensile strength were increased to 96.5 % and 56.2 % of the base mental, respectively. The porosity ratio decreased at first, and then increased with the increase in welding speed. The lowest porosity ratio was 1.99 % when the welding speed was 12 mm × s−1. In summary, the quality of the weld was better when the welding speed was 12 mm × s−1.

Effect of Welding Speed on Fatigue Properties of TC18 Thick Plate by Electron Beam Welding

The welding of 15 mm thick TC18 titanium alloy thick plate was realized by electron beam welding. The effect of different welding speeds (10, 20, 30 mm/s) on the fatigue properties of the electron beam welded joints for TC18 titanium alloy was investigated. The macroscopic morphology, microstructure and fracture characteristics of the joints were analyzed by optical microscope, scanning electron microscopy and transmission electron microscopy, and the fatigue properties of welded joints were studied and tested by an electronic universal testing machine. The results show that the weld fusion zone is mainly composed of columnar β phase and acicular α martensite phase. The upper melting width, the middle melting width and the lower melting width are obviously reduced, and the grain size gradually decreases with the increase of welding speed, which results in the increase of fatigue properties of welded joints. At Nf =107 the fatigue limit of the weld increases by nearly 29% with the welding speed from 10 mm/s to 30 mm/s. The fatigue fracture of the joints can be divided into three typical regions of fatigue crack source zone, expansion zone and instantaneous zone, and the fatigue cracks all originate from the surface of the specimen. With the increase of welding speed, the proportion of instantaneous area decreases and the fatigue performance increases.

EFFECT OF WELDING SPEED ON DEPTH OF PENETRATION, HARDNESS OF HAZ AND LONGITUDINAL DISTORTION OF V-GROOVE BUTT WELD JOINT USING TIG

In this paper study of welding speed and geometry to find out tensile and impact strength in case of butt weld joint will be done. For V-groove geometry different models of plate with various included angles from 30 0 , 40 0 , 50 0 will be made from structural steel (A633 Grade E). Currently different welding speeds are used in precision welding applications such as nuclear reactor pressure vessels, boilers etc. where welding accuracy as well as quality with strength is an important parameter. So in this paper experimentation will be done on different welding speed such as 0.3 cm/sec, 0.6 cm/sec and 0.9cm/sec to prepare a V-groove butt weld joint. Generally the V-groove geometry with included angle up to 60 0 is in use. After studying the Indian Welding Journal published by Indian Welding Society it is observed that strength of joint is depends upon depth of penetration of filler material and Heat Affected Zone. So this paper concentrate on effect of welding speed on depth of penetration of filler, distortion and HAZ.

Experimental study on the effect of welding speed and tool pin profiles on AA6082-O aluminium friction stir welded butt joints

Friction stir welding (FSW) is a novel solid state welding process for joining metallic alloys and has emerged as an alternative technology used in high strength alloys that are difficult to join with conventional techniques. The applications of FSW process are found in several industries such as aerospace, rail, automotive and marine industries for joining aluminium, magnesium and copper alloys. The FSW process parameters such as rotational speed, welding speed, axial force and attack angle play vital roles in the analysis of weld quality. The aim of this research study is to investigate the effects of different welding speeds and tool pin profiles on the weld quality of AA6082-O aluminium. This material has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to-weight ratio. Tri-flutes and taper screw thread pin are used as tool pin profiles in this research. The appearance of the weld is well and no obvious defect is found using these tools. Consequently, the obtained results explain the variation of stress as a function of strain and the effect of different welding speed and pin profiles on yield strength ultimate tensile strength and elongation. The friction stir welded plates of AA6082-O by using the taper screw thread pin profile reaches the ultimate tensile strength of 92.30% of the base metal ultimate strength and % elongation of 27.58%. Keywords: Friction stir welding, AA6082-O aluminium alloy, welding speed, mechanical properties

Effect of friction stir welding speed on the microstructure and mechanical properties of a duplex stainless steel

The present study focuses on the effect of the welding speed on the microstructure and mechanical properties of the stir zone (SZ) in friction stir welding (FSW) of SAF 2205 duplex stainless steel. A single tool, made of a WC-base material, was used to weld 2 mm-thick plates at a constant rotational speed of 600 rpm. X-ray radiography revealed that sound welds were successfully obtained for the welding speeds in the range of 50–200 mm/min, whereas a groove-like defect was formed at the higher speed of 250 mm/min. Moreover, increasing the welding speed decreased the size of the α and γ grains in the SZ, and hence, improved the mean hardness value and the tensile strength of the SZ. These results are interpreted with respect to interplay between the welding speed and the peak temperature in FSW.