JPS6040587Y2 - Heat treatment tank for high temperature steel materials - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat treatment tank for heat-treating high-temperature steel by immersing it in molten salt.

Molten salt, which is used as a cooling medium in the heat treatment of steel materials, has the advantage of having a large heat capacity compared to gas, but has disadvantages such as the fact that the temperature inside the bath tends to be uneven, and it takes a long time to change the temperature. .

The present invention provides an apparatus that eliminates such disadvantages in heat treatment tanks, and will be described below based on an example in which the apparatus of the present invention is applied to a direct heat treatment tank for ring-shaped wire rods after hot rolling.

Figure 1 is a front sectional view of the device of the present invention, and Figure 2 is a partial plan view (A-A cross section in Figure 1), where 1 is a molten salt tank, 2 is a cone roller driven to rotate, and S is a high temperature The wire rod is carried in from the direction of arrow a in FIG.

Reference numeral 3 denotes a salt discharge pipe for discharging the molten salt from the rope entry side 1a to the outside of the tank, and a plurality of suction ports 4 are provided on the lower and side surfaces of the conduit.

A conduit 6 in FIG. 3 that extends from the discharge pipe 3 to the outside of the tank is a cooling tower 7.
The introduction pipe is connected to a salt introduction pipe 8 through the tank, and the introduction pipe branches into branch pipes 9 within the tank, and a salt discharge port 1 is provided on the side of each branch pipe.
0 is opened to form a cooling circulation path for the salt in the tank.

Reference numeral 11 denotes a gas conduit for ejecting pressurized gas into the tank.

14 is an electric heater for melting and heating the molten salt in the tank; 15 is the salt discharge port 10 and the gas jet port 13;
16 in FIG. 3 is a pump for feeding the molten salt in the salt conduit 6 in the direction of the arrow, and 17 is a control for adjusting the amount of cooling water supplied to the cooling tower. Valve 18 is a molten salt temperature sensor.

Next, the operation of the treatment tank of the present invention will be explained.

The molten salt is melted and heated by the electric heater 15.

After hot rolling, the high-temperature wire S is carried in from the tank entry side 1a, dipped in molten salt by a rotationally driven cone roller 2, and then conveyed to the detection side 1b. During this conveyance process, a predetermined heat treatment is carried out. Continuous.

In this way, the high-temperature wire rods are introduced one after another from the steel material entry side and immersed in the molten salt, thereby heating the molten salt in the tank and making it impossible to perform the prescribed heat treatment.

Therefore, the temperature of the molten salt is detected by the temperature detector 18, and this detection signal drives the motor of the pump 16 to suck the molten salt in the tank through the suction port 4 on the steel material inlet side and into the cooling tower 7 through the conduit 6. Cool by passing through cooling water.

The cooled molten salt is detected by a temperature detector 18, and the motor continues to drive until the temperature reaches a predetermined value.

If the molten salt is to be cooled more quickly, the temperature sensor 18
The level of cooling water in the cooling tower 7 is increased by inputting the signal to the control valve 17 and opening the valve.

The cooled molten salt passes through a conduit 8 and a branch pipe 9 and is supplied from a salt outlet 10 to the entire tank area.

In this way, it is possible to equalize the temperature of the molten salt in the tank by taking out only the molten salt on the inlet side of the steel material that is particularly heated and returning it to the entire length of the tank after cooling.

The molten salt discharged from the discharge port 10 is sent upward by the upwardly jetted gas from the gas jet port 13 disposed below the discharge port 10.

Therefore, the wire S is brought into proper contact with the molten salt cooled to a predetermined temperature, and the desired heat treatment is performed.

Further, the cooling water boiled in the cooling tower 7 is recovered as steam.

The device of this invention has piping that discharges the molten salt in the tank from the steel input side and returns it to the entire length of the tank after cooling, so the molten salt can be cooled evenly and quickly, and the molten salt returned to the tank can be cooled evenly and quickly. Since the gas is ejected from below, the cooled molten salt can suitably come into contact with the wire.

Furthermore, when controlling the cooling of the molten salt, it is possible to significantly improve responsiveness by simultaneously operating the pump and supplying cooling water to the cooling tower.

[Brief explanation of the drawing]

Figure 1 is a front sectional view of the device of the present invention, and Figure 2 is A of Figure 1.
-A sectional view and FIG. 3 are explanatory diagrams showing the molten salt circulation system in the device of the present invention. 1... Molten salt tank, 2... Cone roller, 3... Salt discharge pipe, 4... Suction port, 6... Conduit , 7...cooling tower, death...
...Salt introduction pipe, 9...Branch pipe, 10...
... Salt discharge port, 11 ... Gas conduit, 12
... Branch pipe, 13 ... Gas outlet, 1
4... Electric heater, 15... Shield plate, 16... Pump, 17... Control valve, 18... Temperature detector.

Claims (1)

[Scope of utility model registration request] In a molten salt tank equipped with rollers for conveying steel materials, the molten salt in the molten salt tank is discharged from a suction port provided on the inlet side of the steel material, passes through a cooling tower, and is discharged through salt discharge ports provided throughout the longitudinal direction of the tank. 1. A heat treatment tank for high-temperature steel, comprising a cooling circulation path returning the salt into the tank, and a gas conduit having a pressurized gas outlet below the salt discharge port.