Effect of heat treatment on the structure and fatigue behaviour of austenitic Fe-Ni alloy

• Autorzy: Ducki K. J. , Cieśla M.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The paper addresses the problem of determining the dependence between initial heat treatment of an austenitic Fe-Ni alloy and its fatigue life at room and elevated temperature Specimens of Fe-Ni alloy were subject to tests after two variants of heat treatment: solution heat treatment followed by typical single-stage ageing, and solution heat treatment followed by novel two-stage ageing. Design/methodology/approach: For the investigated Fe-Ni alloy after solution heat treatment in the conditions: 980*C/2h/water, two variants of specimen ageing were applied for comparison, i. e. single-stage ageing (715*C/16h/air) and two-stage ageing (720*C/8h+cooling in the furnace up the temperature of 650*C+650*C/8h/air). Specimens that underwent heat treatment were subjected to a static tensile test and low-cycle fatigue tests (LCF), carried out at room temperature and at an increased temperature of 600oC. Findings: It has been found that, at both tested temperatures, the specimens of Fe-Ni alloy after two-stage ageing are distinguished by higher strength properties with a little lower plastic properties. In a case of low-cycle fatigue tests carried out at a temperature of 20*C and 600*C, specimens after single-stage ageing were characterized by higher fatigue life. Lower fatigue life of Fe-Ni alloy after two-stage ageing can be explained by increased brittleness of material in boundary areas. Practical implications: The fatigue life results obtained in LCF conditions can be used in predicting the duration of operation of products made out of Fe-Ni alloy both in room and elevated temperatures. Originality/value: The significance of the applied ageing variants' effect on the mechanical properties and fatigue life of the tested austenitic Fe-Ni alloy is shown in the paper.

Słowa kluczowe

EN

fatigue; metallic alloys; heat treatment; structure

PL

zmęczenie materiału; stopy metaliczne; obróbka cieplna; konstrukcja

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2008
• Tom: Vol. 30, nr 1
• Strony: 19--26
• Opis fizyczny: Bibliogr. 17 poz., il., tab., wykr.

Twórcy

autor

Ducki K. J.

autor

Cieśla M.

• Department of Materials Science, Silesian University of Technology, ul. Krasińskiego 8, 40-019 Katowice, Poland,

Bibliografia

• [1] M. Konter, M. Thumann, Materials and manufacturing of advanced industrial gas turbine components, Journal of Materials Processing Technology 117 (2001) 386-390.
• [2] R. Shargi-Moshtaghin, S. Asgari, The influence of thermal exposure on the γ' precipitates characteristics and tensile of superalloy IN-738LC, Journal of Materials Processing Technology 147 (2004) 343-350.
• [3] S. A. Sajjadi, S. M. Zebarjad, Effect of temperature on tensile fracture mechanisms of a Ni-base superalloy, Archives of Materials Science and Engineering 28/1 (2007) 34-40.
• [4] S. A. Sajjadi, S. M. Zebarjad, Study of fracture mechanisms of a Ni-Base superalloy at different temperatures, Journal of Achievements in Materials and Manufacturing Engineering 18 (2006) 227-230.
• [5] P. Jonsta, Z. Jonsta, J. Sojka, L. Cizek, A. Hernas, Structural characteristics of nickel superalloy Inconel 713LC after heat treatment, Journal of Achievements in Materials and Manufacturing Engineering 21/2 (2007) 29-32.
• [6] N. S. Stoloff, Wrought and P/M superalloys, ASM Handbook, Vol. 1: Properties and Selection Irons, Steels and High-Performance Alloys, ASM Materials Information Society, Ohio, 1990, 950-977.
• [7] F. Schubert, Temperature and Time Dependent Transformation: Application to Heat Treatment of High Temperature Alloys, In: Phase Stability in High Temperature Alloys, Appied Science Publishers LTD, London, 1981, 119-149.
• [8] Ch. T. Sims, N. S. Stoloff, W. C. Hagel, Superalloys II, Ed. A. Wiley Witescience Publications, New York, 1987.
• [9] K. J. Ducki, M. Hetmańczyk, The influence of prolonged aging on the structure and properties of precipitation hardened austenitic alloy, Materials Engineering 4 (2001) 290-293.
• [10] K. J. Ducki, Analysis of the precipitation and growth processes of intermetallic phase in a high- temperature Fe-Ni alloy, Materials Engineering 2 (2007) 53-58 (in Polish).
• [11] K. J. Ducki, Structure and precipitation strengthening in a high-temperature Fe-Ni alloy, Archives of Materials Science and Engineering 28/4 (2007) 203-210.
• [12] K. J. Ducki, Analysis of the structure and precipitation strengthening in a creep resisting Fe-Ni alloy, Journal of Achievements in Materials and Manufacturing Engineering 21/2 (2007) 25-28.
• [13] J. Okrajni, M. Cieśla, L. Swadźba, High-temperature low-cycle fatigue and creep behaviour of nickel-based superalloys with heat-resistant coating, Fatigue and Fracture of Materials and Engineering Structures 21 (1998) 947-954.
• [14] Z. Gronostajski, K. Jaśkiewicz, Influence of monotonic and cyclic deformation sequence on behaviour of CuSi3.5 silicon bronze, Journal of Achievements in Materials and Manufacturing Engineering 15 (2006) 39-46.
• [15] J. Okrajni, A. Marek, G. Junak, Description of the deformation process under thermo-mechanical fatigue, Journal of Achievements in Materials and Manufacturing Engineering 21/2 (2007) 15-23.
• [16] J. Okrajni, A. Marek, G. Junak, Stress-strain characteristics under mechanical and thermal loading, Journal of Achievements in Materials and Manufacturing Engineering 20 (2007) 271-274.
• [17] S. Kocańda, A fatigue cracking of metals, WNT, Warsaw, 1985 (in Polish).