Grooving

Measuring surface crack depth is performed by calibration samples made of the same material like the object being tested. Calibration samples are the plates having narrow grooves like slits of various depth 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm and made by electric erosion method. The samples have dimensions 50 mm X 150 mm x 6 mm and 25 mmx 150 mm x 6 mm and are made of magnetic... 

Inspection of rotors, heat grooves, turbines parts and compressors, heat exchangers. 

When heat-electric generating station turbine rotors are under operation there is a probability of forming surface cracks in axial canal and heat grooves. Evolution of the above defects can cause a serious crash. Therefore, in accordance with safety standards periodic inspection of the rotor component parts is required. 

The maximum thickness of X-raying, measured with wire and groove [4] and achieved with a stationary X-ray unit RUP -150/300 for a tube voltage U=250 kV and current 1=1,5 mA was 40 mm for steel. 

In this figure one can clearly see an image of a weld defective area with a superimposed groove defectometer Fe2 4 mm thick. The depth of a minimum groove was 0,5 mm. One can clearly see a groove 0,2 mm deep, which corresponds to sensitivity less than 2% Both incomplete root penetration and metal weld beads can be clearly seen in the image. 

Steel was used as the control object. During the experiments radiation energy, steel layer thickness, focal distance, roentgen films, screens were varied. Sensitivity was valued according to wire and groove standards. 

The aim of the work we present in this paper is to optimize the control parameters used in particles magnetic and interpret the obtained results. Experiments are performed on samples of welds or materials containing known defects. The realized and tested defects are grooves situated at different depths with variables dimensions. Other types of defects have been studied (inclusions, lack of penetration, etc.). 

Depth measurement possibility on complex-contour parts (in the corners, grooves etc.) by training the device in the dialog mode on control items with certain depth cracks... 

The Washburn model is consistent with recent studies by Rye and co-workers of liquid flow in V-shaped grooves [49] however, the experiments are unable to distinguish between this and more sophisticated models. Equation XIII-8 is also used in studies of wicking. Wicking is the measurement of the rate of capillary rise in a porous medium to determine the average pore radius [50], surface area [51] or contact angle [52]. 

Fit a 50 ml. bolt-head flask F (Fig. 53) with a reflux water-condenser C, to the top of which a dropping-funnel D is fixed by means of a cork having a vertical V-shaped groove G cut or filed in the side to... 

Assemble a 250 ml. three-necked flask, fitted with a stirrer, a reflux condenser and a dropping-funnel, as in Fig. 22(A) and (j), p. 43, or Fig. 23(c), p. 46 (or a two-necked flask, with the funnel fitted by a grooved cork (p. 255) to the top of the condenser). Place 40 ml. of ethanol in the flask, and then add 2-3 g. of sodium cut into small pieces. When all the sodium has dissolved, heat the stirred solution on the water-bath, and run in from the funnel 17 g. (17 ml.) of ethyl malonate and then (more slowly) io-2 g. (12 ml.) of mesityl oxide, the reaction-mixture meanwhile forming a thick slurry. Boil the stirred mixture under reflux for i hour, and then add a solution of 10 g. of sodium hydroxide in 50 ml. of water, and continue boiling the pale honey-coloured solution for ij hours more. 

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