Interrelation between the microstructure and impact toughness of the interface of welded joints of 32HGMA and 40HN2MA steels produced by rotary friction welding
This paper covers the assessment of the influence of the morphological features of the microstructure of medium-carbon alloyed steels, formed at different forces in the process of rotary friction welding (RFW), on the impact toughness of their interface. The paper presents the results of an experime...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Togliatti State University
2025-06-01
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| Series: | Frontier Materials & Technologies |
| Subjects: | |
| Online Access: | https://vektornaukitech.ru/jour/article/view/1060/956 |
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| Summary: | This paper covers the assessment of the influence of the morphological features of the microstructure of medium-carbon alloyed steels, formed at different forces in the process of rotary friction welding (RFW), on the impact toughness of their interface. The paper presents the results of an experimental study of a joint produced by welding tubular billets of 32HGMA and 40HN2MA steels with an outer diameter of 73 mm and a wall thickness of 9 mm with a change in force at the stage of friction (heating) of the billets. The studies of the microstructure, microhardness and impact toughness on samples with a V-notch of welded joints were carried out in the initial state after welding and after tempering at a temperature of 550 °C. Macro- and microfractographic analysis of the destroyed samples was carried out. The study shows that the friction force affects the kinetics of phase transformations, phase composition and microstructure homogeneity in the steel junction zone. With a decrease in this parameter of rotational friction welding, the microstructure heterogeneity associated with the occurrence of upper bainite areas with uneven precipitation of large carbide particles increases, which has a negative effect on the viscosity of the steel interface both in the initial state and after tempering; the fracture mechanism is quasi-cleavage. At higher values of the friction force, the density of high-angle boundaries and the dispersion of the bainite microstructure increase, which ensures higher viscosity and energy capacity of destruction with the formation of a pitted microrelief. The obtained results open up space for regulating the visco-plastic properties of welded joints even at the welding stage without subsequent recrystallisation of the weld zone. |
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| ISSN: | 2782-4039 2782-6074 |