Perm National Research Polytechnic University, Perm, Russia
I. M. Russkikh, Postgraduate Student, Dept. of Metal Science, Thermal and Laser Processing of Metals, e-mail: russkix-igor@mail.ru
Yu. N. Simonov, Dr. Eng., Prof., Head of the Dept. of Metal Science, Thermal and Laser Processing of Metals, e-mail: simonov@pstu.ru
A. A. Shatsov, Dr. Eng., Prof., Dept. of Metal Science, Thermal and Laser Processing of Metals, e-mail: shatsov@pstu.ru

The influence of phase composition of low-carbon martensitic steel (LMS) 08Kh2G2NMFB and elinvar alloy 21NKMT on elastic characteristics (resonance frequency fres., different frequency Δf and elastic modulus E) has been investigated. The mechanical properties were determined. The structure of the investigated materials was studied by diffraction and metallographic methods. The principal structural difference between LMS and elinvar alloy is that LMS contains in its structure about ≈ 95 % of lath martensite, while elinvar alloy can contain up to 50 % of lath martensite and also up to 50 % of reverted austenite. A large number of interfacial boundaries in a material used as a sensing element of an oscillating system represent resistance zones that can contribute energy losses during elastic vibrations. It was found that the tangent of the angle of inclination of the fracture diagram of 08Cr2Mn2NiMoNb material is greater than that of 21NKMT, which indicates a higher value of the elastic modulus. The strength characteristics of 21NKMT alloy are higher than those of 08Kh2G2NMFB (σв – 21 %, HRC – 20 %). However, the low-carbon martensitic steel has better plasticity (δ – 7 %, Ψ – 16 %) and elastic properties (frequency difference Δf – 859 %, resonance frequency fres – 213 %). The values of temperature frequency coefficient (TFC) for LMS 08Kh2G2NMFB and alloy 21NKMT corresponding to the range of - (122÷125)×10-6 1/ºC and - (38÷41)×10-6 1/ºC, respectively, have been calculated. It is established that the temperature dependence of the resonance frequency of LMC 08Kh2G2NMFB is lower than that of alloy 21NKMT, but has changes closer to the linear form.

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