Impact of Electronic Radiation on the Morphology of the Fine Structure of the Surface Layer of R6M5 Steel

Abstract

In recent decades, great efforts have been made to significantly improve the performance characteristics of high-speed steel using various surface hardening techniques. Electron beam modification is engaging because it has an exceptionally high thermal efficiency and can significantly improve steels’ physical and mechanical properties. This work is devoted to researching the fine structure and changing the structural phase state of the surface layer of R6M5 high-speed steel after exposure to an electron beam. Electron beam treatment of steel R6M5 was carried out on a vacuum installation. The structure and phase composition of P6M5 steel samples were studied by transmission electron microscopy. Determined that after electron irradiation, the steel structure as in the initial state consists of martensite, carbides and residual austenite. After electron irradiation, an increase in the volume fraction of lamellar martensite is observed: the fraction of lamellar martensite in the initial state is 80%, and after irradiation, it is ~90% of the total fraction of α′-martensite. The action of the electron beam led to an increase in internal stresses in α′-martensite. Revealed, the value of the scalar dislocation density in R6M5 steel after exposure to an electron beam is higher than in the initial state. A cardinal difference in the state of the material after exposure to an electron beam is the presence of bending extinction contours in all M6C carbide particles.

EFFECT OF THE STRUCTURE FORMED AFTER BULKAND SURFACE HARDENING ON THE HARDNESSAND WEAR RESISTANCE OF 20Cr2Ni4A STEEL

“…But in spite of this the hardness is significantly higher than in traditional heat treatment. This is due to the formation of a highly dispersed metastable structure with a much higher density of dislocations in the surface layer [14,15]. Fig.…”

“…The first sample was cooled in water; the second sample was cooled in oil to room temperature. Surface hardening of 20Cr2Ni4A steel samples was carried out by the electrolytic plasma method on an installation consisting of a 30-kW DC source, an electrolytic cell, a bath, a pump, a heat exchanger, and a stainless steel anode [12][13][14]. The EPH process was carried out in an electrolyte from an aqueous solution containing sodium carbonate (20%) and urea (10%) in the following mode: the applied voltage between the anode and the sample was 320 V, the current density was 25 A/cm 2 , and the plasma exposure time was 2 sec.…”

Research of the Current State and Technological Opportunities of Electrolyte-Plasma Chemical Heat Treatment of Steels

“…В процессе ЭПХТО насыщение реализуется за счет энергии, передаваемой от металлического анода к детали-катоду через слой электролита [4]. При прохождении электрического тока через электролит в зависимости от соотношений площадей активного и пассивного электродов, состава, концентрации, объема, скорости потока электролита, глубины погружения электрода в электролит, расстояния между электродами, температура электрода достигает температуры кипения электролита, с последующим образованием газа в месте контакта электрода и электролита, образуя парогазовую оболочку (ПГО) [7][8][9], которая может обеспечить достижение температуры на поверхности детали до 1100 °С.…”

Effect of Electron Beam Surface Modification on the Plasticity of Inconel Alloy 625

“…They concluded that the mechanical characteristics of the samples were greatly improved after applying the treatment technology due to the formation of a finer microstructure. Rakhadilov et al [9] studied the effect of the electron beam irradiation and modification of R6M5 steel, and the results showed that the volume fractions, as well as the internal stresses of the α' lamellar martensitic structure, increased. Zhao et al [10] have studied the modification of austenitic stainless steel material by an electron beam remelting approach.…”