SU933231A1 - Method of determining casting crystallization time at electromagnetic pressure diecasting - Google Patents

Description

(54) METHOD FOR ELIMINATING THE TIME OF CRYSTALLIZATION OF CASTING UNDER MOLDING UNDER ELECTROMAGNETIC PRESSURE

I

1Biobalance refers to foundry%.

 There is a known method for registering the crystallization time, in which the process endings are judged by the thermal characteristics of the mold G1.

The inertia of measurements with this method is great, and the accuracy is small.

The closest to the invention of the technical essence is a method for determining the crystallization time from mining, including the registration of the end of the phase transition of the casting by measuring the heat of optgavka characteristics at different points along its section t23.

Since the moment of termination of cryocallization is determined by the thermal parameters of the casting, the measurement accuracy is low. The method requires the placement of thermocouples over the entire section of the casting. After the crystallization process is complete, the thermocouples remain in the body (the body restricts the scope of application of the method to laboratory investigations and does not allow widespread adoption in industry.

The aim of the invention is to improve the accuracy of measurements, reducing the externality and ensuring the repeatability of measurements.

This goal is achieved by the fact that in the known method of determining the crystallization time of the valence,.

10 that registers the registration of the phase n © -: transition of the casting, the next step is the transmission of the magnetohydrodynamic fluid circulating in the bath with the metal; electric current pump through Kptro

15 casting and fixing of the scaled growth of the current in the inductor circuit.

The current value in the primary inductor circuit is proportional to the current value.

Claims (2)

20 in a bath of magnetohydrodynamics OO, coca, and the current in the bath, in turn, is proportional to the resistance of the liquid metal coil. The crystallizing elemental liquid element of the liquid method, whose logging changes noticeably in the process of steel painting, occurs because the structure of the metal changes. The resistance of the solid metal is less than liquid. Moreover, this phase transition occurs in; very KopoTKtrii time lapse. In this case, the electric Yaar-h meters of the casting change, and hence the entire liquid-metal pit. The accumulation decreases, and the current increases. The current in the primary inductor circuit also changes accordingly. . Example. Include magnetohydrodynamic pump in a skewed re; press, this ensures the flow of electrical 1-eye through the central channel of the metal pipe, which crystallizes from the drain, conductor bus, metal-bath in the bath. The current value in this mode is. The order is 1OOO-15OO A. The current in the primary inductor circuit is recorded with an ammeter. The process of crystallisation is started. After the end of the phase transition, the resistance of the casting drops by a factor of 7, and the current rises to 7–10 thousand A abruptly. At the same time, the current in the primary circuit of the ish gktor also increases abruptly from 6O to 42OA, which indicates the end of the process of crista pization. Since the inertia of electrical processes, which is less than the thermal processes, the total inertia decreases. nationality measured. When taking measurements, there is no need for liquid metal, which allows repeating measurements on other castings. The proposed method provides on-line information about the state of the casting, and allows to automate the process. Improving the quality of castings by increasing the accuracy of measurements by 20%, increasing the increase in productivity by 2% by automating the opening of the molds will provide an annual economic effect of 15-20 thousand rubles. The invention The method for determining the crystallization time of a casting under a ligier under electromagnetic pressure, which records the end of the phase transition of a casting, which is due to the fact that, with whole improvements in the accuracy of measurements, reduction of inertia and ensuring repeatability of measurements, the end of the phase transition of the casting is registered carrying out the electric current circulating in the metal bath of the magnetohydrodamic pump through the crystallizing casting and fixing the abrupt increase in us and a current of the primary circuit of the inductor. Sources of information, into account in the examination 1. USSR Copyright Certificate No. 431961, cl. B 22 D 27/02, 1970.. 2. Guliev A, P. Hardening of castings. Proceedings of the second meeting on the thermodynamics of casting processes. M., 1958 (prototype;