Actual Problems in Machine Building 2017 Vol. 4 No. 4

Актуальные проблемы в машиностроении . Том 4. № 4. 2017 Материаловедение в машиностроении ____________________________________________________________________ 133 13. Zur festigkeit niedriglegierter stähle mit erhöhtem kohlenstoffgehalt gegen abrasiven verschleiß / O. Hesse, J. Merker, M. Brykov, V. Efremenko // Tribologie Schmierungstechnik. – 2013. – Vol. 6. – P. 37–43. 14. Effect of base metal composition on the toughness in the heat affected zone of DSAW- welded largediameter linepipes / C. Stallybrass, O. Dmitrieva, J. Schroder, A. Liessem // Proceedings of the 6th International Pipeline Technology Conference. – Ostend, 2013. – P. 26–29. LARGE PARTS HEAT TREATMENT SCHEDULE IMPROVEMENT Chertovskih E.O. 1 , Engineer, e-mail: chertovskih13@gmail.com Gabets A.V. 1 , Ph.D. (Engineering), Development director, e-mail: gabets22@gmail.com Gabets D.A. 2 , Ph.D. student, e-mail: gabets22@mail.ru Markov A.M. 2 , D.Sc. (Engineering), Professor, e-mail: andmarkov@inbox.ru Okolovich G.A. 2 , D.Sc. (Engineering), Professor, e-mail: mtio10@mail.ru 1 Altai steel-casting factory, 116/52 Kalinina avenue, Barnaul, Altai region, 656037, Russian Federation 2 I.I. Polzunov Altai State Technical University, 46 Lenina avenue, Barnaul, Altai region, 656038, Russian Federation Abstract The article presents carried out research of steel 20GFL heat treatment influence to toughness KCV -60 , which is reliability assess of products working in harsh climate. Calculation of equations by polynominal of 2 toughness KCV -60 exponents is made on the basis of orthographic central composite planning matrix. Controlled heat treatment with construction of thermal images of incubation, perlite, and intermediate conversion critical points is applied. The ferrit-sorbite-bainite structure was found out by means of transmission electron microscopy. Keywords cold resistance, ferrite-perlite, lower bainite, hardness, allowed perlite, incubatory transformation, critical points, intermediate conversion