SU1748932A1 - Ingot casting method - Google Patents

Description

The invention relates to the field of metallurgy, mainly to the method of casting ingots under dynamic impact conditions.

Proceedings of the method of vibro-impulse action on the melt, including the processing of the crystallizing metal with shock pulses dispersed throughout the height of spmth or vpdleystpme on the melt with a given frequency and energy.

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The disadvantage of these methods is the lack of recommendations on the duration of treatment, which leads to

increased energy consumption tshg

I Mr. && SS $ iSSgli f && 3g &%

There is a known method for producing a THG from casting of a spreading metal into a mold with a profitable extension and the main and conventional effect on the lateral mold of electrohydraulic impact below and above the melt level, the latter stopping when the level of the melt arrives (d superstructure

The disadvantage of this method of mHG is high 3Heprc3aTpafT; When carrying out the method, for example, for an ingot with a mass of 1500 kg, the exposure time is 0.05 times per time. hardening (r3) ingot. The specific operation time of the main vibrators is not specified, which leads either to additional energy consumption, with an overestimation of the exposure time, or to a deterioration in the quality of the foW axis of the ingot zone, the rrptfdecrease in the exposure time.

The closest in technical essence to the proposed method is

P ol chez Shg impact The dream lateral surface of the mold of an electrical; equal blows; dispersed / over the height of the mold, during the time g (0.3-0.4) t3, where g3 ate

WITH

2

00 Yu

S

Yu

ingot solidification time when the stored energy varies from (0.4-0.5) W at the beginning of exposure to (1.5-1.6) W at the end, where W is the average for the period of exposure to energy.

A significant disadvantage of this method is the high energy consumption caused by the occurrence of a gap between the wall of the mold and the ingot and compensated by the duration of exposure and the growth of stored energy.

The aim of the invention is to reduce energy costs by reducing processing time while maintaining the quality of the axial

SLOTKZ ZONES.

The method of producing an ingot involves casting the melt into a mold with a profitable extension and exposure to electro-hydraulic impacts from the lateral outer surfaces of the mold. The impact of electrohydraulic shocks is carried out for 0.1-0.2 times the ingot solidification with simultaneous feeding of melt gap of low-melting additives into the gap formed between the ingot and the mold.

The essential difference of the proposed method is the established dependence of the exposure time (g) on the solidification time (ge) of the ingot. If, according to the prototype, the duration of exposure (0.3-0.4) Gz is determined by the losses in the gap, then according to the proposed method, the exposure time is a much smaller part of the solidification time, has narrow limits of variation: m (0.1-0.2 ) te. For example, the exposure time by a known method g 0.3 g3 - t - 0.4 g3. The duration of exposure in this case is 3–2 times the optimum average value established by the method providing for compensation of the gap with a low-melting alloy. The energy consumption in the known methods will be more than 3-2 times higher than B proposed.

The method is carried out as follows.

Prior to the onset of exposure, the ingot solidification time is determined. In this case, one can use both theoretical dependences and experimental data. After that, the limits of the exposure time are determined and the average value is chosen.

Gv.s. - -- BUT . Taking into account the mass and physical properties of the melt, the law of change in the stored energy of the electrohydropulse device is set and the casting and processing of the melt with impact impulses begins. After filling the profitable part of the mold (2/3 tall), the casting is stopped and the processing is temporarily suspended. A heat-insulating plate with a gap to the lateral surface of the profitable part is placed on the surface of the liquid metal, a low-melting mixture is fed into the gap and the impact continues to

0.1 t3 + 0.2ge for Gw gr, where Gr 0 is the processing time at the stage of casting the mold. As low-melting additives, for example, metal compounds on zinc and lead bases, calcium salts, lime-fluorine slag can be used. The amount of the mixture must ensure the compensation of the gap throughout the processing stage of the shock pulses. As a result of filling the gap, the acoustic contact is improved and the efficiency of the electrohydropulse effect is increased (see table).

Example. The method was tested on model ingots of tin alloys with simultaneously operating four

5 electrohydropulse generators located at the ingot height levels. These approbations indicate that with relative time, the effects of t / Gz 0 to 1-0.2 are significantly improved.

0 performance indicators (as compared with the variant without effect). In the base case, these figures are much worse. Thus, the size of the macrograin is reduced to 54-49% (high-conductive mixture) or

5 59-57% (low heat conductive mixture); the degree of degassing increases to 23-25%. With a relative setting time of r / Gz 0.1 (i.e., at g / t3 0.05: 0.09), the rates of convective flows decrease significantly and temperature drops increase (from 310 and 9 to 235 to 30%, respectively ). These changes lead to a decrease in the effectiveness of the effect with a deviation from t / he of 0.1 to one hundred

decrease, degree of degassing

decreases from 23 to 21%, the size of a macrogrill from 54 to 69% (a highly heat-conducting mixture).

Starting from 7 / g3 0.2 (for example, t / g3: 0 0.22). there is no significant change in quality indicators, therefore, this mode is not economically viable

The proposed processing method for

Compared with the prototype, it can be reduced by 5.

- {15 ... 24)% solidification time,

- (28 ,,. 36)% size of a macrogrill,

- (50 .., 61)% degree of development of V-shaped segregation;

- (28. 36)% degree of development of L-o (5 times segregation;

- (38 ... 41)% overheating of the melt - increase by:

- 12% degree of melt degassing;

-148-160% flow rate

Yield at the introduction of high-heat melting (low-melting metal) compared to low-heat melting (salt melt) is 5 ... 6% lower, which is explained by the deterioration of the heat insulating ability of the profitable extension in the first case.

As shown by experimental studies, electrohydropulse treatment when the gap is filled with melt low-melting additives makes it possible to increase:

- cost-effectiveness of the process of electrohydraulic pulsed processing by more than 1.5-2.2 times due to reduction of the processing time;

- reliability of equipment operation due to shortened time of impact of shock loads on it

- repair capability of the process unit due to an increase in the resistance of the electrode system of the electric discharge vibrator.

Claims (1)

Claim Invention A method for producing an ingot that includes melt casting into a mold with a profit extension and electro-hydraulic impacts from the lateral surfaces of the mold, in order to reduce energy costs by reducing the processing time while maintaining the quality of the axial zone of the ingot, electro-hydraulic impact during 0.1 ... 0.2 ingot solidification time at simultaneously feeding the melt gap of low-melting additives into the gap between the ingot and the mold.