Influence of stress relief annealing on the microstructure and properties of GX12CrMoVNbN9-1(GP91) cast steel

• Autorzy: Golański G. , Kupczyk J. , Kolan C.
• Języki publikacji: EN

Abstrakty

EN

The paper presents an effect of stress relief annealing, applied to casts after the repair by welding, on the microstructure and mechanical properties of quenched and tempered martensitic GX12CrMoVNbN9 – 1 cast steel (called GP91). The test pieces being the subject of research were taken out from a test coupon. Heat treatment of GP91 cast steel was carried out at the parameters of temperature and time appropriate for the treatment of multi-ton steel casts, while stress relief annealing was performed at the temperatures of 730 and 750ºC. After quenching and tempering GP91 cast steel was characterized by the microstructure of high-tempered martensite with numerous precipitations of carbides of diverse size. Mechanical properties of the investigated cast steel after heat treatment fulfilled the standard requirements. Stress relief annealing contributes to the processes of recovery and recrystallization of the matrix as well as the privileged precipitation of M₂₃C₆ carbides on grain boundaries. Changes in the microstructure of the examined cast steel cause deterioration in mechanical properties – the higher the temperature of stress relief annealing, the greater the deterioration.

Słowa kluczowe

EN

heat treatment; cast steel microstructure; mechanical properties; martensitic cast steel

PL

obróbka cieplna; mikrostruktura staliwa; właściwości mechaniczne; staliwo martenzytyczne

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2011
• Tom: Vol. 11, iss. 2 spec.
• Strony: 59--63
• Opis fizyczny: Bibliogr. 11 poz., rys., tab., wykr.

Twórcy

autor

Golański G.

• Institute of Materials Engineering, Czestochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

autor

Kupczyk J.

• Institute of Materials Engineering, Czestochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

autor

Kolan C.

• Institute of Materials Engineering, Czestochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

Bibliografia

• [1] K. H. Mayer, H. Cerjak, P. Hofer, E. Letofsky, F. Schuster, Evolution of microstructure and properties of 10% Cr steel castings, Microstructural development and stability in high chromium ferritic power plant steels, Edited by A. Strang and D. J. Gooch, The Institute of Materials, London, 1997, 105–122.
• [2] G. Golański, High chromium martensitic cast steels for power plant, XXI, Energetyka, 2010, 58–61.
• [3] R. Hanus, Advanced 9 – 12%Cr cast steel grades, research –foundry process development – quality – experience, 4th International Conference “Advances in Materials Technology for Fossil Power Plants”, Hilton Head Island, South Carolina, 2004, 638-651.
• [4] F. A. Schuster, R. Hanus, H. Cerjak, Foundry experience in large turbine casings and valve bodies made of steel castings P91 and G-X12CrMoWVNbN10 11, IMechE, 1996, 11–22.
• [5] R. Hanus, Heavy steel casting components for power plants “mega – components” made of high Cr – steels, 9th Liege Conference: Materials for Advanced Power Engineering 2010, 2010, 286-295.
• [6] S. Rajca, E. Grzesiczek, Material state of steam turbine casing after the repair with welding, Energetyka, 12, (2001), 777–780.
• [7] ECCC Data Sheet, 2005.
• [8] G. Golański Influence heat treatment parameters on microstructure and mechanical properties of high-chromium GX12CrMoVNbN9-1 (GP91) cast steel, Inżynieria Materiałowa, 6, (2010), 1441–1445.
• [9] G. Golański, Influence of Heat Treatment on Microstructure and Properties of GX12CrMoVNbN9-1 Cast Steel, Arch. Foundry Eng. , 10, 3, 2010, 89-94.
• [10] G. Golański, Microstructure and Mechanical Properties of G17CrMoV5-10 Cast Steel After Regenerative Heat Treatment, J.Pressure Vessel Technol., 132, 6, 064503-1-064503-5.
• [11] J. Dobosiewicz, Influence of operating conditions on the changes in mechanical properties of steam turbine cylinders, Energetyka, 1, 1992, 27–30.