X-RAY CONTROL OF WELDED JOINTS ACCORDING TO GOST AND ISO SYSTEMS

The results of comparative analysis of assessing modes, parameters and means of radiographic control of welded joints of critical duty using the Russian (GOST) and international (ISO) standards are presented. Comparison was carried out by the sensitivity of control, permissible radiation energy (affecting the formation of the contrast of the radiation image), and minimum focal length (determining the sharpness of the resulting optical image). Requirements of the ISO system for the sensitivity of control are higher, than that of the State standard specification system. The sensitivity assessment in the ISO system is carried out using the wire indicator, the dimensions of which are smaller than the dimensions of the grooves of the groove sensitivity standard, regulated by GOST. However, the choice of the radiation energy in the system requirements GOST is stricter than that in the ISO system. This provides enhanced contrast of the generated radiation image. The conversion of the radiation image into an optical one using the ISO system is carried out using film systems of a high optical density. According to the ISO requirements transformation of the radiation image to the optical one is to be carried out using film systems of the certain class. And, as a result, transformation of the radiation image to the optical occurs in the field of high gradients. GOST imposes no requirement to film systems, since there is the only one class of domestic film on the market. The requirements to the minimum allowable focal length (GOST) are higher compared to the ISO system, which makes it possible to obtain better sharpness of radiographic images. Performance monitoring according to GOST also exceeds that of ISO. As a result, we can conclude that the quality welded joints should be monitored using the complete set of the accepted standards.

1. Kablov E. N. Innovative development of VIAM Federal State Unitary Enterprise of GNTs Russian Federation on implemen-tation “The strategic directions of development of materials and technologies of their processing for the period till 2030” / Aviats. Mater. Tekhnol. 2015. N 1. E 3 - 33 [in Russian].

2. Kablov E. N. Key problem — materials / Tendencies and reference points of innovative development of Russia is pollard. — Moscow: VIAM, 2015. E 458 - 464 [in Russian].

3. Kablov E. N. Material of new generation — basis of innovations, technological leadership and national security of Russia / Intell. Tekhnol. 2016. N 2(14). E 16 - 21 [in Russian].

4. Ospennikova O. G., Lukin V I., Afanasyev-Hodykin A. N., et al. Perspective development in the field of the high-temperature soldering of hot strength alloys / Aviats. Mater. Tekhnol. 2017. N S. E 144 - 158 [in Russian].

5. Ospennikova O. G. Results of implementation of the strategic directions on creation of new generation of heat resisting cast and deformable alloys and staly for 2012 - 2016 / Aviats. Mater. Tekhnol. 2017. N S. E 17 - 23 [in Russian].

6. State Standard GOST ISO 17636-1-2017. Nondestructive control of welded connections. Radiographic control. — Moscow: Standartinform, 2018. — 34 p. [in Russian].

7. State Standard GOST 7512-82. Control nondestructive. Connections welded. Radiographic method the State and international standards in the field of non-destructive testing. — Moscow: Nauchno-tekhnicheskii tsentr po besopasnosti v promyshlennosti Gosgortekhnadzora Rossii, 2004 [in Russian].

8. State Standard GOST 20426-82. Control nondestructive. Defectoscopic methods radiation. Scope. — Moscow: Nauchno- tekhnicheskii tsentr po besopasnosti v promyshlennosti Gosgortekhnadzora Rossii, 2004 [in Russian].

9. State Standard GOST 23055-78. Control nondestructive. Welding of metals by melting. Classification of welded connections by results of radiographic control. — Moscow: Nauchno-tekhni- cheskii tsentr po besopasnosti v promyshlennosti Gosgortekhnadzora Rossii, 2004 [in Russian].

10. Stepanov A. V, Kosarina E. I., Evtyukhova O. S., et al. Algorithm of development of technological cards of radiographic control according to the European norms of EN / Kontrol. Diagnostika. N 2. 2013. E 27 - 32 [in Russian].

11. Demidov A. A., Stepanov A. V, Turbin E. M., et al. About the modes of the x-ray control providing forming of radiation images with set contrast / Aviats. Mater. Tekhnol. 2016. N 4. E. 80 - 85 [in Russian].

12. Dobromyslov V. A. Radiation methods of non-destructive testing. — Moscow: Meshinostroenie, 1999. — 104 p. [in Russian].

13. Stepanov A. V, Kosarina E. I., Savvina N. A. Comparison of requirements of X-ray control and quality of radiographic pictures in the European norms and the Russian standards / Vestnik MEI. 2011. N 4. E 85 - 89 [in Russian].

14. Kosarina E. I., Stepanov A. V, Savvina N. A. Radiographic technical films of RT-K and RT-7G. Results of their testing / Aviats. Mater. Tekhnol. 2012. N 1. E 37 - 42 [in Russian].

15. ISO 10675-2008. Non-destructive testing of welded seams — acceptance levels for radiographic control. E 1. Steel, nickel titanium and their alloys. — Moscow: Standartinform, 2016. — 16 p. [in Russian].