Issue << content << Magnetic Inspection of Welds Fatigue Resistance


DOI: 10.12737/15091

2015. Vol.18. No. 4, pp. 17-21

Magnetic Inspection of Welds Fatigue Resistance

B. E. Popov

Introduction. Complexity of welded joints nondestructive testing under operation conditions is associated with the heterogeneity of the metal structure within the heat-affected zone, which is a stress concentrator; the metal structure in this zone is being changed under cyclic loads. The work aim was to investigate the possibility of applying a coercimetry method to diagnostics of welds working under cyclic loads.
Method. At low-cycle fatigue irreversible damage accumulation takes place even in a defect-free weld. The magnetic structurescope KRM-Ts-K2M was used for detection of this damage by the value of the coercive force increase. The impact of load parameters on a coercive force was studied on the basis of static and cyclic testing of samples with butt and fillet (T-shaped) welds.
Results. Numerous static and cyclic testing of welds and base metal have enabled the author to determine correlation between a coercive force value and weld resource parameters for the conventional steel grades St3sp, 09G2S and 10KhSND. Prospects of small (with the base ≤ 20 mm) sensors application for weld local diagnostics has also been shown in the work.
Conclusion. Combination of magnetic structural testing by a coercive force method with an ultrasonic inspection makes it possible to predict a physical resource of metal work at the examination of hazardous production facilities.
 
Keywords: magnetic structural testing, coercive force, steel, welds, static and cyclic load, resource evaluation
References
1. Popov B. E., Kotelnikov V. S., Levin E. A. Bezopasnost truda v promyshlennosti [Industrial operation safety]. 2001, no. 2, pp. 44–49 (in Russ.).
2. Kotelnikov V. S., Popov B. E., Bezlyudko G. Ya., and Levin E. A. Sb. trudov NPK «Problemy proizvodstva i bezopasnoy ekspluatatsii podemnykh sooruzheniy v Ukraine i Rossii» [Proc. of NPK “Problems of Manufacturing and Safe Operation of Hoisting Equipment in Ukraine and Russia”]. 2002, pp. 232–245 (in Russ.).
3. Popov B. E., Bezlyudko G. Ya., Elkina E. I., and Solomakha R. N. V mire NK [NDT World]. 2009, no. 2(44), pp. 28–32 (in Russ.).
4. Prokhorov A. V. Magnitnyy kontrol (po koertsitivnoy sile) urovnya nakoplennykh ustalostnykh povrezhdeniy pri tsiklicheskikh nagruzkakh v svarnykh soedineniyakh staley 09G2S i VSt3sp5 [Magnetic testing (by a coercive force) of accumulated fatigue damage level under cyclic loads in welded joints of steels 09G2S and VSt3sp5]. (Ufa State Petroleum Technological University). Available at: http://www.ogbus.ru/authors/Prokhorov/prokh1.pdf (in Russ., accessed 19.11.2015).
5. Vonsovskiy S. V. Magnetizm [Magnetics]. Moscow, Nauka, 1971. 1032 p. (in Russ.).
6. Mikheev M. N., Gorkunov E. S. Magnitnye metody strukturnogo analiza i nerazrushayushchego kontrolya [Magnetic methods of structural analysis and nondestructive testing]. Moscow, Nauka, 1993. 252 p. (in Russ.).
7. Shcherbinin V. E., Gorkunov E. S. Magnitnyy kontrol kachestva metallov [Magnetic inspection of metals quality]. Ekaterinburg, URO RAN, 1996. 264 p.
8. Bida G. V., Gorkunov E. S., Shevnin V. M. Magnitnyy kontrol mekhanicheskikh svoystv prokata [Magnetic inspection of rolled stock mechanical properties]. Ekaterinburg, UrO RAN, 2002. 252 p.
9. Sandomirskiy S. G. Raschet i analiz razmagnichivayushchego faktora ferromagnitnykh tel [Calculation and analysis of demagnetizing factor of ferromagnetic bodies]. Minsk, Belorusskaya nauka, 2015. 243 p.
10. Ivanova V. S., Terentev V. F. Priroda ustalosti metallov [The nature of metal fatigue]. Moscow, Metallurgiya, 1975. 455 p.
11. RD IKTs «Kran» 007-97-02. Magnitnyy kontrol napryazhenno-deformirovannogo sostoyaniya i ostatochnogo resursa podemnykh sooruzheniy pri provedenii ikh obsledovaniya i tekhnicheskom diagnostirovanii (ekspertize promyshlennoy bezopasnosti) [Magnetic inspection of hoisting equipment stress-strain state and residual life at its examination and technical diagnosis (expert examination of industrial safety)], approved by Rostekhnadzor 14.04.2004, no. 12-07/360.
 
published
NDT in Mining Industry

MAIN FEATURE:
NDT in Mining Industry

CONTACTS

5 Udelny Pr.
St. Petersburg
007 812 670 7609
007 812 670 7611


NDT World, Russian Quarterty Journal
©2000-2016 All rights reserved