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Information × Registration Number 0217U003834, 0116U008778 , R & D reports Title Investigation of the effect of volume and surface hardening treatments on the structure, mechanical and performance properties of steels and cast irons. popup.stage_title Head Cheiliakh Alexandr Petrovich, Доктор технічних наук Registration Date 11-08-2017 Organization State Higher Educational Institution "Pryazovskyi State Technical University" popup.description2 The object of the study is sheet rolling low-alloy structural steel, tool steel, which were subjected to various methods of thermal and thermomechanical hardening and layer of high-strength cast iron, which properties were formed after plasma treatment. The purpose of the work is to improve the quality of metal products through alloying, thermal and thermomechanical treatments, evaluation of the factors of strengthening the materials under study. Research methods - analytical calculations, investigations with MSC Visual Nastran element complex, macro-, microstructure analysis, electron microscopy, X-ray analysis, mechanical properties tests. Questions about efficiency of methods of improvement quality of iron-carbon alloys are considered and solved. It is shown that the increase of finish rolling temperature of steel Х70 from 720 °С to 780 °С slightly reduces strength and toughness KCU-60, but increases KCV-20, which is caused by simultaneous beneficial influence of grain refinement. It was found that Q-n-P treatment with quenching at 100 °C and further aging at 250-350 °C ensures the production of a heterogeneous microstructure in steel 75CrMn2Si with an increase of volume fraction of residual austenite. It is shown that Q-n-P-treatment increases the abrasive wear resistance of this steel. The influence of various factors on the hardening of steel is established. It is proved that the main contribution in hardening is introduced by grain-boundary and solid-solution mechanisms. Treatment without surface melting promotes obtaining in the quenching zone compressive stresses. In the melted layers arise tensile stresses, and in the hardened layers arise compressive stresses. With an increase in the thickness of the fused layer, the tension stresses in it increase. The structures of the discrete modified layer, which corresponds to the highest coefficient of wear resistance, have the most optimal character of the division of equivalent stresses. Product Description popup.authors Єфременко Василь Георгійович Гаврилова Вікторія Григорівна Григор'єва Марія Олексіївна Зарнаджи Вадим Іванович Мак-Мак Наталія Євгенівна Рябікіна Марина Анатоліївна Самотугіна Юлія Сергіївна Чейлях Олександр Петрович popup.nrat_date 2020-04-02 Close