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Registration Number

0221U103810, 0116U006493 , R & D reports

Title

Development of steel with nitride dispersion strengthening and technology of its melting and heat treatment of railway wheels with increased resource exploitation

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Head

Shipitsyn Sergiy Yakovich, Доктор технічних наук

Registration Date

25-02-2021

Organization

Physico-technological institute of metals and alloys National academy of Sciences of Ukraine

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In 2019. according to the IV stage of project implementation P7.2.1. experimental wheel steels of grades K (standard), AF with dispersion nitride hardening and CAF with complex dispersion and solid-soluble hardening were made. From cast steels by hot deformation in the laboratory mode t = 1050-950 oC and the degree of deformation δ = 25% (forging and factory mode t = 1260 oC δ = 50% made samples, which investigated the effect of hot deformation on the austenitization temperature during heat treatment It was previously established that the factory mode of hot deformation allows to reduce the austenitization temperature from 950 - 1000 оС, which was required in laboratory conditions to develop steels, to 860… 900 оС, which is required for the production conditions of wheels at PJSC “Interpipe NTZ ”. In the reporting period of 2020. according to the V stage of the project P7.2.1 methods of light and scanning electron microscopy with microanalysis of inclusions established jumps and mechanisms of processes. The main ones are: - complete dissolution of VN nitrides at the factory mode of hot deformation and reduction of 2 - 3 times the inhomogeneity of vanadium concentrations in the microvolumes of the matrix; - reduction of 2 - 2.5 times the size of VN particles during cooling of steel after hot deformation; - increase several times the dissolution rate of VN during austenitization; - increasing the degree of supersaturation of the solid solution, which changes when the steel is released the mechanism of separation of VN nitrides from heterogeneous to homogeneous, which provides their intra-grain separation with increased particle dispersion. The possibility of using CAF steel in industrial conditions without reconstruction of the operating thermal equipment is established, it is allowed to begin organizational activity on carrying out experimental - industrial tests of steel.

Product Description

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Kirchu Ivan F
Shypytsyn Serhii Y.

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2021-02-25