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A dilatometric study of steel 45Kh5MF used for making rolling mill rolls is performed. The results of the dilatometric and metallographic analyses are used to determine the kinetics of the perlitic transformation in the steel under continuous cooling. The developed method of numerical simulation of structural transformations under continuous cooling is used to solve the inverse problem and to plot a computational isothermal diagram of decomposition of supercooled austenite in steel 45Kh5MF in the range of perlitic transformation. To check the solution obtained an experimental isothermal diagram of decomposition of austenite in steel 45Kh5MF in the perlitic range is plotted. The data of both diagrams match accurately enough.

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Water-drip cooling devices based on centrifugal jet atomizers are studied experimentally. Their main operating characteristics such as the irrigation density, the uniformity of the distribution of irrigation over the cooled surface, the dependence of the heat transfer factor on the surface temperature, etc. are determined. The effect of the design and production parameters of the quenching facilities on their operating characteristics and mode of cooling of large steel articles is considered for mill rollers as an example. The results of the tests are used to design cooling facilities and heat treatment processes for mill rollers with the use of water-drip quenching.

A combined computational and experimental technique is developed for implementing a scientifically based approach to the selection of a technology of heat hardening of welded joints of drill pipes made of steel 25KhGM with the use of water-drop quenching. The basic service characteristics of the water-drop cooling device are presented. An analytic model that relates the parameters of the water-drop quenching device (standard size and number of jets in device, pressure of fed water, distance from the jet nozzle to the cooled surface) to the properties of the welded joint is proposed. With the new technique the construction of a quenching device may be developed and the technology of heat treatment of the welded joints of drill pipes optimized in order to increase the level of mechanical properties.

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