Heat Resistance of Centrifugally Cast Tubes Made of 32%Cr-43%Ni Refractory Alloy and Its Welded Joints at Temperatures up to 1150 °C

Abstract

The results of microstructura l analysis, short-term and long-term strength tests of modified sparingly alloyed refractory alloy of 32%Cr-43%Ni and its welded joints are presented. A quantitative analysis of the dispersed phases in the initial state and after long-term strength tests has been carried out. It is shown that the network of carbide-intermetallic precipitates persists after long-term strength tests at a temperature of 1150 °C. This ensures the ability of the developed alloy and its welded joints to withstand high-temperature creep for a long time. It has been established that after long-term strength tests at a temperature of 1150 °C, niobium carbide particles present in the base metal and weld metal are almost completely transformed into an intermetallic phase based on Cr-Ni-Si-Nb-N. The penetration of atmospheric nitrogen into the metal stimulates this process.

Keywords

Heat-resistant alloy / Long-term strength / Microstructure / Centrifugal cast tubes / Carbides

Acknowledgments

Experimental studies were carried out on the equipment of the Core shared research facilities “Composition, microstructure and properties of structural and functional materials” of the NRC «Kurchatov Institute»—CRISM “Prometey”.

Author Contributions

S.N.P.—Conceptualization, Writing—original draft, A.V.T.—Data curation, Editing, I.P.P., E.V.Z., J.A.B., Y.S.P.—Investigation.

Ethics Statement

Not applicable.

Informed Consent Statement

Not applicable.

5Data Availability Statement

Data will be available on request.

Data Availability Statement

Data will be available on request.

Funding

This research was carried out with the financial support of the Russian Science Foundation, project (Agreement No. 21-73-30019-P).

Declaration of Competing Interest

The authors declare that they have no conflict of interest.

References

[1] Böhler Welding. Welding Materials for the Chemical and Petrochemical Industries; Böhler Schweißtechnik Austria GmbH: Kapfenberg, Austria, 2008; 44p.

[2] Reihani A, Haghighi RD. Failure analysis and weld ability improvement of 35% Cr-45% Ni heat resistant alloy. Eng. Fail. Anal. 2015, 52, 97-108.

[3] Reihani A, Razavi SA, Abbasi E, Etemadi A. Failure analysis of welded radiant tubes made of cast heat-resisting steel. J. Fail. Anal. Prev. 2013, 13, 658-665.

[4] Popova I, Oryshchenko A, Utkin YA, Petrov S, Tsemenko A. Study of heat resistance characteristics of metal of centrifugally cast tubes made from 45Cr32Ni43SiNb alloy and their welded joints at temperatures up to 1150° C: Part 1. The heat resistance characteristics of tubes at temperatures up to 1100° C. Inorg. Mater. Appl. Res. 2021, 12, 1459-1466.

[5] Kondrat’ev SY, Ptashnik A, Anastasiadi G, Petrov S. Analysis of transformations of carbide phases in alloy 25Cr35Ni by the method of quantitative electron microscopy. Met. Sci. Heat Treat. 2015, 57, 402-409.

[6] Voicu R, Andrieu E, Poquillon D, Furtado J, Lacaz J. Microstructure evolution of HP40-Nb alloys during aging under air at 1000 °C. Mater. Charact. 2009, 60, 1020-1027.

[7] Rudskoy AI, Kondrat’ev SY, Anastasiadi GP, Oryshchenko AS, Fuks MD, Petrov SN. Transformation of the structure of refractory alloy 0.45C-26Cr-33Ni-2Si-2Nb during long-term high-temperature hold. Met. Sci. Heat Treat. 2014, 55, 517-525.

[8] Barbabela GD, de Almeida LH, da Silveira TL, Le May I. Phase characterization in two centrifugally cast HK stainless steel tubes. Mater. Charact. 1991, 26, 1-7.

[9] de Almeida Soares GD, de Almeida LH, da Silveira TL, Le May I. Niobium additions in HP heat-resistant cast stainless steels. Mater. Charact. 1992, 29, 387-396.

[10] Abbasi M, Park I, Ro Y, Ji Y, Ayer R, Shim J. G-phase formation in twenty-years aged heat-resistant cast austenitic steel reformer tube. Mater. Charact. 2019, 148, 297-306.

[11] Guo X, Ni Y, Gong J, Geng L, Tang J, Jiang Y, et al. Formation of G-phase in 20Cr32Ni1Nb Stainless Steel and its Effect on Mechanical Properties. Acta. Metall. Sini. (Eng. Lett.) 2017, 30, 829-839.

[12] Zabavicheva E, Petrov S, Kondrat’ev SY. Transformation of Niobium Carbide in Heat-Resistant Alloys Based on Fe-25Cr-35Ni at 900° C and 1150° C. Met. Sci. Heat Treat. 2024, 65, 605-612.

[13] Kondrat’ev SY, Anastasiadi G, Rudskoy A. Nanostructure mechanism of formation of oxide film in heat-resistant Fe-25Cr-35Ni superalloys. Met. Sci. Heat Treat. 2015, 56, 531-536.

[14] Rudskoi A, Kondrat’ev SY, Anastasiadi G, Tsemenko A. Mechanism of the Oxidation of Phases in Heat-Resistant Alloys of the Fe-25Cr-35Ni System. Phys. Met. Metallogr. 2021, 122, 275-285.

[15] Kondrat’ev SY, Tsemenko A. Mechanism of Formation of Surface Protective Layer in Heat-Resistant HP40NbTu Alloys during High-Temperature Oxidation. Met. Sci. Heat Treat. 2024, 66, 177-192.