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 Wysłany: Czw 14:43, 13 Sty 2011 Temat postu: moncler daunenjacke Large-diameter heat pipe weld |
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Large-diameter heat pipe weld X-ray detection
According to the selection of weld penetration through the main layout parameters are determined according to the translation from the head X. 10 using a method in this field testing in convenience, but using this method was found through a period of time according to the weld, the resulting uneven blackness of radiographs, sometimes at both ends of the film within the Department of Black 40mm ~ 50ram Difference of about 0.6 or so, which is related to the inhomogeneity of radiation intensity, in order to use the cathode side of the beam, and frequent move-ray machine,[link widoczny dla zalogowanych], but also increase the exposure time, the film quality and testing efficiency. To explore the weld is uniform ray ray intensity at the field, and meet the defect detection rate across the state, get a good quality film. Head tilt + shift from the use of easy to implement these requirements, the specific operation is a constant head at one end,[link widoczny dla zalogowanych], while the other end of the booster (to do a ramp wedge), in fact, dip one end of the nose is the focus of debate for the center, inversion clockwise or clockwise to raise the nose at one end, according to the width of the weld, thereby making the cathode-ray Cambodia aligned under the weld, according to analysis of Figure 1, the cathode side of the beam angle of 10. 13. ,[link widoczny dla zalogowanych], The intensity between 104 and 105, in this angle range. Cambodia and uniform radiation intensity of the larger, the calculation of the head angle adjustment in 7. 10. Within the scope of testing to meet the requirements of the two layouts shown in Figure 4. 3.3 according to the specific example through LI = 50ram; L2-630ram; head used to ramp from 7 to 10. . Transillumination conditions: models: XX a 2005; Weld width 6 = 12-15ram; more than high school 2ram; of screen: Lead foil 0.025; cassette on the back lining 1.5ram stereotype; voltage of a 180 ~ 195kV; Current = 5mA; exposure time = 5mln; Film: Tianjin Industrial Ⅱ; development time from 4 to 8 minutes. Ray detection by the time standard requirements. Way through the double wall alone and according to law, to take 1.1, focal length 680mm, calculated by the formula formula. @ = Cos a 'king one by one D · sinO1sm'r =- million = sin-t630 Li 4.62. : Sin a 1 (O.863 × 0.416) = 21.0. 24.62 a 10 + a +21. = 45.62. \. . (Times) AB = Leff eleven 507mm length L according to a transparent one by one-31-4X630-494mm length L according to the first guy through the effective elastic film set the standard length of Le {f the relevant requirements, and we use 240mm ~ 360mm long film. Patch: make the image on the film at the weld dry in a. Transillumination half hat-ray angle position of the center. And black uniform,[link widoczny dla zalogowanych], the best way is to measure out (or calculated) is the circumference of pipe probe, and whichever is the circumference of the i / 2 stick Department to the center of the film, the perimeter of the t / Z at positioning the other end as the radiation center, so that the beam center-aligned double-wall alone and this point transillumination. Other markers placed by GB3323-87 standard, cavity liner bag film dumb 1l a 1.5ram thick hafnium skin, and use the magnetic clip to pocket fixed to the outer wall of the workpiece 0'm ... a - ... r ... trampling a one of a b. Oblique + shift head 1 from the appropriate drying to Figure 4, arranged according to signal through the field after 4 Results and discussion of theoretical feasibility of using the head tilt + translation method; of large-diameter pipe weld heat-site x-ray testing, quality inspection station was commissioned to complete the detection of municipal tasks, for the entire project to provide a reliable basis for acceptance. Detection of 720 × 8ram, 630 × 8ram, 426 × 8ram three sizes girth weld heat pipe, a total length of pipe line for several kilometers, a total of nearly 400 film and theory from the actual testing the following conclusions can be drawn for comparison . 4.1 The theory that occurred in X-ray tube x-ray is a continuous X-ray,[link widoczny dla zalogowanych], various wavelengths are, where the soft-ray attenuation coefficient than the hard-ray attenuation coefficient is much greater. That the actual testing. Ray source side of the wall there, and the thickness of the plate is not the role of play can be approximated, but the larger diameter. Constant in thickness, the closer the source side wall window x-ray machine ideal location, the greater the filtering effect, the greater the sensitivity increasing trend. Be noted that according to our different diameter pipe through when the benefit from the exposure of the selected line on the basis of tube voltage to increase 8 ~ 12kV voltage, from the negative point of view the best film does not affect the contrast, and even film defects the details more clearly as head tilt and pan using a certain distance, to ensure the shuttle to come forward like defects, and large-diameter heat pipe girth weld spot x-ray detection has a higher detection efficiency. (Continued on page 6) a 11 -
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