SU1458398A1 - Method of determining the temperature of central zone of massive articles in hardening - Google Patents

Abstract

The invention relates to the field of metallurgy and can be used to control the temperature states of the central zones of massive products during heat treatment. The aim of the invention is to increase the measurement accuracy and reduce its duration. Previously for different temperatures of the central zone of a heat-treatable rotor with a diameter of 800 mm and a weight of 12 tons of st. 25X2HMFA is determined by calculation using a computer, the rise in temperature of the surface of the product when cooled in air after being in a quenching medium for different temperatures of the core of the product. The product is heated to the temperature of quenching and cooled. Then, to determine the temperature state of the central zones, the product is discharged from the quenching medium and the actual rate of temperature rise on the surface of the product is recorded during its exposure to air, for example, by a low-inertia contact thermocouple, which reduces the measurement time to 3-4 minutes. Next, the measurement data of the actual change in surface temperature is compared with the preliminary results. thus determining the temperature state of the central zones of the product. The information obtained allows us to determine whether the product should be quenched or, since the core has an optimum temperature to obtain the required properties, further cooling should be carried out in air. The application of the method allows to significantly improve the quality of massive products. with Iggja OS OS SA: its OS

Description

The invention relates to metallurgy and can be used to control the temperature states of the central zones of massive products.

when they are processed.

The purpose of the invention is to improve the measurement accuracy and reduce its duration.

Example. The rotor is quenched at a model of 0,800. 25H2NMFA

1458398

hourly 12 t. To improve the quality of heat treatment by eliminating the lead and warping during quenching while ensuring the required complex of mechanical properties, a mode of adjustable rotor model with a water shower with a specific water flow of 0.005 m / m to 500 ° C and the final one was developed. cooling with compressed air pressure of 0.08 MPa. This mode of cooling adeni; reduces temperature differences between the center and the surface of the workpiece. When determining the quality of the six heat-treated using the proposed method, there were no defects at all, while

 using a known method (after cooling for the time envisaged by the technological process, the product is unloaded from Qaq, Q of the environment on the air and the surface temperature is recorded with a thermocouple after 20-35 minutes, which does not allow determining the center temperature with sufficient accuracy, the cooling process between prices 1 iOP r1 s; 1./.g.j l l... - -JE - ь -.

1k in the temperature range of the formation is considered complete if the rates of plastic deformations, that the surface area did not exceed a certain value depending on the steel grade and its dimensions) of the six rotors, two were rejected due to the presence of cracks.

Claims (1)

Thus, the application of the proposed method improves the quality of massive products by increasing the accuracy of determining the temperature of the central zones and reducing the time spent on the implementation of the method. Invention Formula The method for determining the temperature 30 of the central zone of massive products during the quenching process, which includes cooling |, reduces the quenching stresses, I Preliminarily determine the rate of increase of the temperature of the rotor surface after removing it from the quenching medium to air (in this case, after turning off the water shower} for different temperatures in the central zone (600, 500, 400 ° C) and build nomop rpaMMiuie curves. With the actual performance of the mode after the 70-minute In cooling mode of the rotor, the supply of a water shower is stopped and the surface temperature is measured with a low-inertia thermocouple — for 1 min for 3 min, i.e., the actual temperature rise is determined. A comparison of the calculated and experimental results suggests that the temperature of the central zone is 600 ° C. Therefore, further cooling with a water shower is carried out for 20 minutes. After the shower is turned off, the rate of increase in surface temperature is measured. Comparison of calculated and experimental data The removal of products in the quenching medium and the subsequent fixation of the surface temperature after removing it from the quenching medium, and in order to improve the accuracy of measurement and reduce its duration, preliminarily calculate the rate of increase of the surface temperature 40 at different temperatures in its central zone, the actual rate of increase in temperature is measured. computation and experimentation. .and compare the calculated velocities with factual indications that the temperature is central zone reached 500 ° С. Thereafter; With one of the calculated speeds, the final cooling is done by making the temperature of its central compressed air. zones. eight When determining the quality of the six heat-treated using the predicted method. The protors were completely free of defects, while using a known method (after cooling for the time envisaged by the technological process, the product is unloaded from the quenching medium to air and the surface temperature is recorded with a thermocouple after 20-35 minutes, which does not allow determining the center temperature with sufficient accuracy, the cooling process is -JE- - - s -. They are considered complete if the surface temperature did not exceed a certain value depending on the steel grade and its dimensions. Of the six rotors, two were rejected due to the presence of cracks. The method for determining the temperature of the central zone of solid products in the quenching process, including cooling products in the quenching medium and the subsequent fixation of the surface temperature after removing it from the quenching medium, so that, in order to improve the accuracy of measurement and reduce its duration, the surface temperature rise rate at different temperatures in its central zone, the actual rate of increase in temperature is measured. compare calculated speeds with background