Investigating the effects of welding process on residual stresses, microstructure and mechanical properties in HSLA steel welds

Abstract This paper deals with the dissimilar friction stir lap welding of AA2198 and AA7075 sheets. The influence of processing parameters, namely welding speed and tool rotational speed on joint features, microstructure, and mechanical properties were investigated implementing a full factorial design of experiments. During the welding process, axial and transversal forces were continuously measured using a dedicated sensed fixture aiming at the correlation of this processing parameter with the quality of the achieved joints. The reported outcomes showed a very narrow processing window in which it was possible to avoid the formation of defects while the formation of an hook was observed for all the joints welded. The influence of the weld bead morphology on the lap shear strength was elucidated proving that the strength is ruled by the hook morphology. A correlation between the process parameters and the forces arising was also attempted. The final microstructure of the joints was studied and explained and also compared with the microhardness results.

Download Full-text

Microstructure and mechanical properties investigation of stellite 6 and Stellite 6/TiC coating on ASTM A105 steel produced by TIG welding process

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2018.07.044 ◽

2018 ◽

Vol 350 ◽

pp. 648-658 ◽

Cited By ~ 11

Author(s):

A. Shahroozi ◽

A. Afsari ◽

B. Khakan ◽

A.R. Khalifeh

Keyword(s):

Mechanical Properties ◽

Welding Process ◽

Tig Welding ◽

Stellite 6 ◽

Microstructure And Mechanical Properties

Download Full-text

Microstructure and Mechanical Properties of Resistance Heat-Assisted High-Power Ultrasonic Dissimilar Welded Cu/Al Joint

Metals ◽

10.3390/met9080873 ◽

2019 ◽

Vol 9 (8) ◽

pp. 873 ◽

Cited By ~ 2

Author(s):

Li ◽

Cao

Keyword(s):

Mechanical Properties ◽

High Power ◽

Welding Process ◽

Ultrasonic Welding ◽

Hybrid Welding ◽

Research Attention ◽

Microstructure And Mechanical Properties ◽

Power Ultrasonic ◽

Average Shear ◽

Significant Research

The Cu/Al dissimilar joint, welded by high-power ultrasonic welding technology, is still facing challenges despite the significant research attention it has attracted. In this work, the microstructure and mechanical properties of resistance heat-assisted high-power ultrasonic welding of Cu/Al are investigated, in order to obtain high-quality joints. The intermetallic compound (IMC) at the interface of hybrid welding is primarily composed of Al2Cu, and the additional resistance of heat reduces the thickness of this brittle IMC layer. The average shear stress for the joint prepared by hybrid welding is ~97 MPa, which is higher compared to the joint strength without resistance heat (90 MPa). Moreover, the duration of the hybrid welding process is shorter. Finally, the fracture of the hybrid weld is found to be a brittle–ductile hybrid mode.

Download Full-text

Characterization and Evaluation of Mechanical Properties and Residual Stress in Aluminum-Magnesium Alloys Welded by the FSW Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1012.349 ◽

2020 ◽

Vol 1012 ◽

pp. 349-353

Author(s):

D.B. Colaço ◽

M.A. Ribeiro ◽

T.M. Maciel ◽

R.H.F. de Melo

Keyword(s):

Mechanical Properties ◽

Residual Stress ◽

Residual Stresses ◽

Welding Process ◽

Bending Test ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Friction Stir ◽

Aluminum Magnesium Alloys

The demand for lighter materials with suitable mechanical properties and a high resistance to corrosion has been increasing in the industries. Therefore, aluminum appears as an alternative due to its set of properties. The aim of this work was to evaluate residual stress levels and mechanical properties of welded joints of Aluminum-Magnesium alloy AA 5083-O using the Friction Stir Welding process. For mechanical characterization were performed a uniaxial tensile test, Vickers hardness, bending test and, finally, the determination of residual stresses. It was concluded that welding by FSW process with an angle of inclination of the tool at 3o, established better results due to better mixing of materials. The best results of tensile strength and a lower level of residual stresses were obtained using a tool rotation speed of 340 RPM with welding advance speed of 180 mm/min and 70 mm/min.

Download Full-text