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1500MW Nathpa Jhakri Hydroelectric Project-Stress Relieving Aspects in the Pressure Shafts Steel Liner
Published in C.V.J. Varma, A.R.G. Rao, Tunnelling Asia ’97, 2020
Vipin Arora, Vatsal Chopra, Arun Goyal
There are some other methods which are equally important to be applied when stress relief annealing is avoided. They are as follows: The allowable stresses in the designs can be reduced by suitably deciding the weld efficiencies after considering the effect of the residual stress by welding, reliability of welding and procedures of welding etc. The welding efficiency may be reduced to compensate the residual stress as shown belowFigures in parenthesis are the welding efficiency in case NDT be made for all along the weldings (100%).Hydro Pressure test must be applied for the stress relief instead of annealing.100% Non destructive testing to check the soundness of welds and keep the allowable stresses for the welding joints with in the limits.
Design, construction and operation safety of a reinforced soil dam
Published in Jean-Pierre Tournier, Tony Bennett, Johanne Bibeau, Sustainable and Safe Dams Around the World, 2019
Seepage from the tailrace duct joints.- During the test stage, water was found seeping through the construction joints of the tailrace duct. In order to make the duct impervious, steel lining of 1.00 m in diameter and 9 mm in thickness was placed inside. All welding joints passed the penetrating dye and ultrasound testing, in addition to the x-rays performed on the welding. The spacing between the concrete duct and the lining was backfilled with concrete. In order to ensure the backfilling of all gaps, concrete was pumped in three stages and as the welding and placing of steel pipes progressed (Figure 8). An inspection is conducted inside the lining on a yearly basis and it is operating adequately.
Detection of defects in a welded joint by scanning contact potentiometry
Published in Nondestructive Testing and Evaluation, 2021
A. I. Alwaheba, V. I. Surin, T. E. Ivanova, O. V. Ivanov, V. G. Beketov, V. А. Goshkoderov
Manual scanning of welding joint surface was carried out in order to detect defects in welding and to determine their location. Potentiograms are built using different structural levels of the diagnostic signal (SLS) (SLS = |log|φ||, where φ is the diagnostic signal which is related to difference in work function between sensor and sample materials). Point scanning measurement (step wise of about 2 mm) was carried out along the eight tracks. The distance between tracks was 1.5 mm and the average scanning speed was approximately 2 mm/s.
Joints properties in rotary friction welding of AA5083-H112 aluminium alloy
Published in Welding International, 2022
Agus Sasmito, Mochammad Noer Ilman, Priyo Tri Iswanto, Refai Muslih
In this study, the similar friction welding joints of 5083-H112 aluminium alloy plates were done at three different rotational speeds at constant time and pressure. The macro- and microstructure examinations, tensile test and microhardness were conducted to characterize the welding joints under various rotational speeds. Finally, residual stress measurements and fatigue test accompanied by fractography study were carried out.