The thermal fatigue behaviour of creep-resistant Ni-Cr cast steel

• Autorzy: Piekarski B.
• Języki publikacji: EN

Abstrakty

EN

The study gives a summary of the results of industrial and laboratory investigations regarding an assessment of the thermal fatigue behaviour of creep-resistant austenitic cast steel. The first part of the study was devoted to the problem of textural stresses forming in castings during service, indicating them as a cause of crack formation and propagation. Stresses are forming in carbides and in matrix surrounding these carbides due to considerable differences in the values of the coefficients of thermal expansion of these phases. The second part of the study shows the results of investigations carried out to assess the effect of carbon, chromium and nickel on crack resistance of austenitic cast steel. As a criterion of assessment the amount and propagation rate of cracks forming in the specimens as a result of rapid heating followed by cooling in running water was adopted. Tests were carried out on specimens made from 11 alloys. The chemical composition of these alloys was comprised in a range of the following values [...]. The specimens were subjected to 75 cycles of heating to a temperature of 900oC followed by cooling in running water. After every 15 cycles the number of the cracks was counted and their length was measured. The results of the measurements were mathematically processed. It has been proved that the main factor responsible for an increase in the number of cracks is carbon content in the alloy. In general assessment of the results of investigations, the predominant role of carbon and of chromium in the next place in shaping the crack behaviour of creep-resistant austenitic cast steel should be stressed. Attention was also drawn to the effect of high-temperature corrosion as a factor definitely deteriorating the cast steel resistance to thermal fatigue.

Słowa kluczowe

EN

heat treatment; cast steel Ni-Cr; thermal fatique; microstresses; trays and fixtures

PL

obróbka cieplna; staliwo Ni-Cr; zmęczenie termiczne

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2007
• Tom: Vol. 7, iss. 4
• Strony: 155--158
• Opis fizyczny: Bibliogr. 11 poz., rys., tab., wykr.

Twórcy

autor

Piekarski B.

• Szczecin University of Technology, Al. Piastów 17, 70-310 Szczecin, Poland,

Bibliografia

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• [2] R. ¯uchowski, Analysis of failure process of metals under conditions of thermal fatigue. Wydaw. PW, Wrocław 1986. Monografie nr 18 (in Polish).
• [3] A. Drotlew, B. Piekarski, Creep-resistant casting of grates - constructional and technological notice. Arch. Odlew., No. 1 (2001) 446-453 (in Polish).
• [4] B. Piekarski, Austenitic steel casting used in constructional of carburising furnaces - theoretical and practical aspects of increasing life. Prac. Nauk. Polit. Szczecińskiej, nr 573, Szczecin 2003 (in Polish).
• [5] M. Pachowski, The effect of material on the durability of pieces subjected to the thermal shocks. Prac. IMP, z. 68 (1970) 33-45 (in Polish).
• [6] W. Steinkusch, Hitzebeständiger Stahlguß für Wärmebehand-lungsanlagen. Gas Wärme Inter., No. 6 (1987) 340-346.
• [7] G. Y. Lai, Heat-Resistant Materials for Furnace Parts, Trays, and Fixtures. ASM Handbook, 4 (1991) 510-518.
• [8] Ceramic Industry΄s - Materials Handbook, 2001.
• [9] Gutowski P., Analysis of cracking cases in grates used in carburising furnaces. Diss., Polit. Szczecińska, Szczecin 1989 (in Polish).
• [10] J. Tuleja, P. Gutowski, M. Leus, Tessellated stresses in stable austenitic casting alloy under carburisation and rapid changes of temperature. Arch. Odlew., No. 22 (2006) 590-597 (in Polish).
• [11] J. Kilarski, A. Studnicki, St. Jura, The thermal fatigue of Cr and of Cr-Ni cast steel. Arch. Odlew., No. 1 (2001) 193-198 (in Polish).