ON THE ISSUE OF IMPROVING RELIABILITY OF THE WELDED JOINTS IN MINING EQUIPMENT

UDC 621.791.052: 620.178.5.05

Authors:

Makeiev S.Ju., Ph.D. (Tech.), Senior Researcher (IGTM NAS of Ukraine)

Makeieva G.S., Doctoral Student (NMetAU)

Abstract. 

The key issue of the article is a study of ways for improving reliability of the mining equipment by removing the stresses from the welded joins, which are the weakest areas in the welded structures of the mining equipment. Many researchers have found that quality of a welded join is mainly affected by its stressed state. The objective of the work was to study an impact of vibromechanical treatment on mechanical properties of and redistribution of residual stresses in the welded joints of the mining technical equipment made of structural steel. To solve the assigned task the experiments were performed in order to investigate the welded joints made by: HFC welding (high-frequency currents); and electric-arc welding with and without vibration during the welding operations. Stress concentration in the welded joints were measured by method of metal magnetic memory which showed dependences between the stress changes along the entire length of the test sample and the three types of welding: HFC welding, electric arc welding and electric arc welding with vibration. The obtained dependencies showed that stress in the welded joint was the lowest at welding with vibration. In two other cases, stress was, on average, twice higher at high frequency welding and 4 times higher at electric arc welding. Thin sections of the seam surfaces of the above mentioned types of welding joints were investigated, and 3D models of the joint surfaces were created. Results of the research of reducing the residual stresses in the welded joints have given the grounds to recommend the vibromechanical treatment for improving quality and reliability of the mining machines. Thanks to the vibromechanical treatment, residual stresses in the area of the welded seam reduces by 2-4 times, and number of different irregularities in the seam structure, which are the sites of the weld failure leading to premature failure of the mining equipment, essentially reduces.

Keywords:

residual stress, vibromechanical treatment, welded joint.

References:

1. Kvaginidze, V.S. and Chupeykina, N.N. (2011), “Constructive - technological measures to improve the performance of welded joints of steel structures of mining and transport equipment”, Gorniy informatsionno-analiticheskiy bulleten [Mine information - analytical bulletin] ,  no.12,  pp. 185-192.

2. Antonov, A.A., Steklov, O.I. and Sidorin, Yu.V. (2012), “Research of technological residual stresses in welded joints of pipelines”, Zagotovitelnye proizvodstva v mashynostroenii, no. 3, pp.13-18.

3. Stefan, V.V., Tentler, A.V. and Podolsky, V.E. (2003), “Level management concentrators of mechanical stress strain state in structural steel”, Kontrol. Diagnostika, no.7, pp. 61-64.

4. Tung, Ryan C.; Garg, Anurag; Kovacs, Andrew; Peroulis, Dimitrios; and Raman, Arvind, (2013), "Estimating residual stress, curvature and boundary compliance of doubly clamped MEMS from their vibration response", Birck and NCN Publications, vol. 4, pp. 1-14.

5. Letunovskiy, A.P. and Novikov, G.V. (2010), “Removal of residual welding stresses”,  Sfera Neftegas, no. 1, pp. 156-157.

6. Korolev, A.A., Korolev, A.V., Fomin, A.A., Savran, S.A., Balaev, A.F and Yakovishin, A.S. (2015), “Vibromechanic Way to Remove Residual Stresses”, Trans Tech Publications,  vol. 1064,  pp. 103-107.

7. Gaydenyuk, N.D., Seregin, N.Y., Savenkov, D.P. and Maytakova, A.V. (2013), “By developing the concept of reduction of residual stress in welded joints in electron beam welding caused by thermoelastic phenomena”, Vestnik Sibirskogo gosudarstvennogo aerocosmicheskogo universiteta, no.3(49), pp.169-174.

8. Trufanov, N.A., Smetannikov, O.J. and Trufanov, A.N. (2011), “Models of formation of fields of technology and in terms of residual stresses relaxation transition”, Bulletin Nijnegorodskogo universiteta im. N.I. Lobachevskogo, no. 4 (5), pp. 2534-2536.

9. Antoshina,T.V. (2009) “Influence of residual stresses on the stability of the plates, prestressed local thermal effect” , Zbіrnik Naukovykh prats Ukrayinskogo naukovo-doslіdnogo ta proektnogo instituta stalevykh konstruktsіy іmenі V.M. Shimanovskogo, no.4, pp.181-186.

10. Kalmykov, M.A., Strutinskii, V.B. and Schelokov, V.S. (2011), “General principles of describing the process of vibratory processing with an external source of dynamic effects”, Vostochno – evropeysky jurnal peredovuch technologiy [Eastern European Journal of advanced technologies], no.3 (49), pp. 45-49.

About the authors:

Makeev Sergey Jurievich, Candidate of Technical Sciences (Ph.D), Senior Researcher, Senior Researcher in Department of Mineral Mining at Great Depths, M.S. Polyakov Institute of Geotechnical Mechanics under the National Academy of Sciences of Ukraine (IGTM, NASU), Dnepropetrovsk, Ukraine, Этот адрес электронной почты защищен от спам-ботов. У вас должен быть включен JavaScript для просмотра.

Makeieva Anna Sergeievna, Doctoral Student, Department of Project Management National metallurgical academy of Ukraine ( NMetAU),  Dnepropetrovsk, Ukraine, Этот адрес электронной почты защищен от спам-ботов. У вас должен быть включен JavaScript для просмотра. .