Study of weld defect behavior under the operational conditions of heat transfer element: first phase

Hypervapotron based Heat Transfer Elements (HTE) are used as cooling elements in Neutral Beam systems. A first phase of study has been initiated by simulating the heat flux and other operational parameters on the welded coupon, cut from assembled HTE by using in GLEEBLE 3800 system. The actual heat flux, cooling conditions and pressure conditions were simulated in multiplication of 1000 and 3500 cycle. After application of subjected thermal cycles, the coupon was tested for non-destructive examination to generate the data base of change in size or shape of ground pores. Advanced nondestructive examination (NDE) techniques like computer tomography (CT) having accuracy of detecting defect up to 1 micron was explored and applied for the purpose. Combination of more than one conventional NDE techniques was also explored for the precise definition of the defect. This paper present the preliminary results of the experiments carried out on welded coupon drawn from assembled HTE. (author)