Czasopismo
2008
|
Vol. 8, iss. 2
|
93-98
Tytuł artykułu
Autorzy
Wybrane pełne teksty z tego czasopisma
Warianty tytułu
Języki publikacji
Abstrakty
This paper describes an analysis of a defective microstructure of a mill roll. For this purpose, a piece of a broken roll was collected. That roll was made of mottled cast iron. Its microstructure consisted of modular graphite, transformed ledeburite and a matrix composed of bainite and martensite. Metallographic investigations were performed nearby the fracture in the roll. Observations were conducted on polished sections, first not etched, and then etched, which allowed us to trace carefully the propagation of the fracture. There was found a strict correlation between the microstructure of the roll and the progress occurring in the crack. It was ascertained that the basic reason for the damage to the roll was banded precipitations of ledeburitic cementite. In addition, cementite formed a continuous network. Another microstructure defects of that roll are also precipitations of secondary carbides on the boundaries of former grain of austenite as well as the occurrence of upper bainite in its matrix. The results obtained hereunder allow broadening the data base relative to the genesis of damages to mill rolls, which in future will permit one to design a proper microstructure of cast iron mill rolls. Proper microstructure of cast iron mill roll should be shaped at the stage of designing the chemical composition, conditions of crystallization or heat treatment if any.
Czasopismo
Rocznik
Tom
Strony
93-98
Opis fizyczny
Bibliogr. 15 poz., rys., tab.
Twórcy
autor
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Reymonta 23, 30-059 Kraków, jkrawczy@metal.agh.edu.pl
Bibliografia
- [1] S. Stachura, T. Borek, J. Jańczyk, Investigation of alloy high carbon cast steel for mill rolls, Metallurgy and Foundry Practice, 111 (1987) 203-214 (in Polish).
- [2] J. Głownia, The role of segregation in fracture toughness of cast steel rolls, Metallurgy and Foundry Practice, 111 (1987) 215-223 (in Polish).
- [3] J. Krawczyk, J. Pacyna, A. Kokosza, Fracture toughness of cast materials for mill rolls, Proceedings of the 6th International Conference for Mesomechanics, Multiscaling in Applied Science and Emerging Technology, Fundamentals and Applications in Mesomechanics, Patras, Greece (2004) 203-207.
- [4] J. Krawczyk, J. Pacyna, The heat treatment influence on structure and properties of cast steels for mill rolls, Hutnik-Wiadomości Hutnicze, No. 7-8 (2004) 370-374 (in Polish).
- [5] J. Krawczyk, E. Rożniata, J. Pacyna, The influence of hypereutectoid cementite morphology upon fracture toughness of chromium-nickel-molybdenum cast steel of ledeburite class, Journal of Materials Processing Technology, 162-163 (2005) 336-341.
- [6] E. Rożniata, J. Pacyna, Structure of chromium-nickel-molybdenum cast steel after additional heat treatment, Archives of Foundry, vol. 6, No. 21(1/2) (2006) 85-92 (in Polish).
- [7] S. Rzadkosz, L. Staszczak,: High chromium cast iron for impellers of shot blasing machines, Archives of Foundry, vol. 6, No 21(1/2) (2006) 71-78 (in Polish).
- [8] R. Wielgosz, I. Pietryka, Selection of cast iron for fuse-links to eccentric presses, Archives of Foundry, vol. 6, No. 21(1/2) (2006) 79-85 (in Polish).
- [9] E. Fraś, M. Górny, M. Kawalec, Effect of nitrogen on structure and mechanical properties of ductile iron witch small additions vanadium and niobium, Archives of Foundry Engineering, vol. 7, iss. 1 (2007) 81-84.
- [10] E. Fraś, M. Górny, M. Kawalec, Effect of small additions of vanadium and heat treatment on mechanical properties ductile iron, Archives of Foundry Engineering, vol. 7, iss. 1 (2007) 73-76.
- [11] E. Fraś, M. Górny, M. Kawalec, Effect of small additions of vanadium and niobium on structure and mechanical properties ductile iron, Archives of Foundry Engineering, vol. 7, iss. 1 (2007) 89-90.
- [12] E. Fraś, M. Kawalec, Effect of small additions of vanadium and niobium on structure mechanical properties of nodular cast iron, Archives of Foundry, vol. 6, No. 21(1/2) (2006) 383-388 (in Polish).
- [13] E. Guzik, Some selected problems concerning the processes of cast iron improvement, Archives of Foundry. Year 2001, Monograph No. 1M (in Polish).
- [14] Cz. Podrzucki, Cast iron - structure - properties - application, ZG STOP, Cracow (1991) (in Polish).
- [15] J. Krawczyk, Structural reasons for the wear mechanisms leading to defects in cast iron mill rolls, Tribology, Theory and Practice, No. 2, vol. 212 (2007) 353-366 (in Polish).
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.baztech-article-BPZ4-0018-0020