Theoretical and experimental investigations have been carried out to examine the in uence of laser power and on time on the weld thermal cycle and weld metal microstructure and hardness during laser spot welding of low alloy steel. A transient heat transfer model that takes into account the temperature dependence of material properties and latent heat of phase transformation is employed to sim...

In the present study, the three components of the residual leakage magnetic fields from the flaws were measured with the MI sensor. Furthermore, finite element analysis for the three components of the residual magnetic fields was carried out. From these experimental and analytical results, By showed the two pairs of the maximum and the minimum and can evaluate the flaw length. In the case of th...

Neutron diffraction was used to measure the residual stress distribution in an FeAl weld overlay on steel. It was found that the residual stresses accumulated during welding were essentially removed by the post-weld heat treatment that was applied to the specimen; most residual stresses in the specimen developed during cooling following the post-weld heat treatment. The experimental data were c...

This paper discusses two common problems, “weld tenting” and low coating thickness over the external weld, and their causes in traditional three layer polyolefin pipeline coatings. To tackle these problems, a new approach to applying multilayer polyolefin coating to pipes is introduced. The new system consists of side-extruding high density polyethylene over a graded structure polyethylene (GSP...

Urban industrial water system parameter fluctuation producing uncertainty may not occur in a control input channel, can be applied mismatching uncertain system to describe. Based on Lyapunov direct method and linear matrix inequality, design the urban industrial water mismatching uncertain system feedback stabilization robust control scheme. Avoid the defects that the feedback stabilization con...

Ultrasonic metal welding has been used widely to join battery cell terminals, or tabs (either Al or Cu), with bus bars (Cu) to form assembled battery packs in battery electric vehicles. However, the mechanism of ultrasonic welding for Al/Cu is still not well understood. In this work, the microstructures of the ultrasonic welds between three layers of lithium-ion battery tabs (either Al or Cu) a...

To achieve good corrosion resistance in a weld is much more challenging than for plate or sheet material, which has undergone controlled rolling, heat treatment and pickling processes in the steel mill. The choice of weld procedure and parameters, filler metal and shielding gas all play important roles. For duplex and lean duplex grades it is essential to ensure that an adequate amount of auste...

Titanium alloys have found increased applications in various industrial sectors. One of the critical issues in quality control is the weld penetration during welding. In the present paper, tungsten inert gas (TIG) welding of Ti-6Al-4V alloy with and without an activating flux was conducted. The effect of the activating flux on Ti alloy welding was investigated. A data acquisition system was use...

Titanium-alloy weldments have been extensively used in engineering structures, and accurate estimation of the fatigue life is beneficial for avoiding catastrophic failures in titanium-alloy structures. The weld pore is a common defect in these weldments that significantly influences the fatigue process. In this study, the weld-pore size and depth and its effect on the fatigue life of Ti-6Al-2Zr...