JPS6031887B2 - Steel pipe cooling control method on the exit side of a regular machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling cooling of a steel pipe after leaving a forming machine in a seamless steel pipe production line in order to refine the crystal grains of the product.

Conventionally, no means has been developed to properly control the cooling rate on the line after the steel pipe exits the forming machine, but in the present invention, controlling the cooling rate after exiting the forming machine is We focused on the fact that it is extremely effective in making grains finer. Therefore, the purpose of the present invention is to obtain a low-temperature impact value higher than that of a competitive structure by making the crystal grains finer, and in addition to this, an aim is to reduce the area occupied by the cooling bed. It is. The main components of the present invention are as follows.

In other words, a skew angle is attached to the conveyor table installed between the regular machine and the cooling table to rotate and propel the steel pipe in a spiral manner, and the above-mentioned compare table is provided with one or more units for cooling the outer surface of the steel pipe. providing a header;
The temperature of the steel pipe is measured before and after the cooling header, the deviation of the temperature in front of the header from the reference value is determined, and the amount of cooling medium supplied to the cooling header is adjusted, thereby controlling the cooling rate. The main objective is to control the temperature of the cooling curve at this time, from the viewpoint that the cooling rate after exiting the regular machine has a large effect on the refinement of crystal grains. The gradient is compared with a reference cooling gradient, and the deviation is captured to correct the cooling state. Next, the configuration of the present invention will be specifically explained.

In FIG. 1, the rollers 21 of the conveyor table 2 interposed between the standard machine 1 and the cooling table 3 are each provided with an hourglass-shaped roller having a certain skew angle. The skew angle of the rollers 21 is formed as a skew angle of about 1 to 50 with respect to the axis that should be perpendicular to the direction of movement of the tube, so that the tube transferred over the rollers is propelled in a spiral manner while rotating. It is designed so that it will be done. The motor 22 for driving the rotation of the rollers may be attached to each roller individually as shown in the figure, but several rollers may be grouped together and linked together using a chain or the like. At a plurality of positions on the conveyor table 2, headers 4 are arranged at predetermined intervals for cooling the outer surface of the tube to be transferred.

As shown in FIGS. 2 and 3, this outer surface cooling header 4 has a structure that injects the cooling medium evenly from the circumferential direction. It is desirable to set the nozzle inclination angle so that it is in the forward direction and in the opposite direction with respect to the circumferential movement direction. The header shell 41 has a structure that allows adjustment in the vertical direction so that the center can be aligned according to changes in the pipe diameter. A temperature detector 51 is provided on the inlet side of the outer cooling header 4 to measure the surface temperature of the cooled tube.

A fin radiation thermometer or the like is suitable as the temperature detector 51,
This detected value is input from the thermometer 52 to the calculator 53. The calculator 53 stores a reference value of a predetermined cooling gradient preset in the controller 5, compares the actual value introduced from the thermometer 52 with the reference value, and calculates the value based on the deviation. The injection amount of the cold soot is adjusted by adjusting the degree of the valve 43 provided in the cold soot supply pipe 42 of the external cooling header 4. Next, an embodiment of the present invention will be described along the progression of the tube.

While the pipe is caught in the regular machine 1, it moves straight in the direction of the wire, but when the entire length of the pipe leaves the regular machine 1, it is transferred onto the conveyor/oraer 2 and the skew angle is adjusted. accompanying roller 21
is propelled in a spiral by the feed of When the tube reaches the position of the first stage header 4, the tube end touches the limit switch 44 (
(see FIG. 2), the cylinder 45 is actuated and the temperature sensor 51 is lowered. The detection element faces the tube surface with an extremely small interval and performs temperature detection. The actual value of the cooling gradient detected by the temperature detector 61 is compared with the cooling gradient of the reference cooling curve in the calculator 53, and the relationship of the valve 43 is adjusted based on the deviation to correct the cooling state. In other words, when the actual value is higher than the standard value, the opening of the valve becomes large and a large amount of cold soot is injected from the nozzle of the hetsuda.On the other hand, when the actual value is lower than the standard value, The valve 43 is throttled and the injection amount of cold air is adjusted to be small. This kind of adjustment of the injection amount is performed individually for each cooling tube, but there is a moderate delay time between temperature detection and injection, so the injection amount is adjusted to adjust the cooling rate according to the temperature. is controlled. When the tube end passes the limit switch 44, the cylinder 45 operates to pull up the temperature sensor 51, and in synchronization with this operation, the injection from the nozzle is stopped. below,
Similarly, the tube is cooled according to a predetermined cooling pattern set in the controller 5, and when the tip of the tube comes into contact with a stopper 23 provided at the end of the conveyor, the kicker 24 is activated and the tube is cooled. -Transferred to table 3. When the residual heat held in the tube on the cooling table needs to be cooled more quickly, the inner surface cooling header 6 is used to inject cold soot from the tube end to the inner surface to accelerate cooling. According to the method of the present invention, cooling control is performed at 0/sec from 1 to 10 o'clock in the process where the subordinate structure is left to cool to the atmosphere and no cooling control is performed, thereby achieving a quality in which the low-temperature shock value is higher than the competitive structure. It is extremely advantageous because it is possible to obtain steel pipes of

In the cooling process, the entire circumference of the tube is cooled evenly, which is effective in obtaining products of uniform quality.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of the method of the present invention. FIG. 2 is a side cross-sectional view of a header for cooling the outer surface of the tube, which forms the main part of the method of the present invention. FIG. 3 is a sectional view taken along line mm in FIG. 2. 1: Regular machine, 2: Conveyor table, 21: Conveyor roller, 22...Motor, 23: Stopper, 24: Locker, 3: Cooling table, 4: External cooling header, 41: Header shell, 42: Refrigerant supply pipe line, 43: Valve,
44: Limit switch, 5: Controller, 51: Temperature detector, 52: Thermometer, 53: Arithmetic unit, 6: Internal cooling tube, 7: Cooled pipe. Total figure 2 figure 3 figure

Claims (1)

[Claims] 1. A conveyor table provided between a regular machine and a cooling table is provided with a skew angle to propel the steel pipe to be cooled in a spiral manner, and the conveyor table is provided with one or more headers for cooling the outer surface of the steel pipe. The cooling rate is determined by measuring the temperature of the steel pipe before and after at least one of the external cooling headers, determining the deviation of the temperature in front of the header from a reference value, and adjusting the amount of cooling medium supplied to the header. 1. A steel pipe cooling control method in seamless steel pipe manufacturing, characterized by controlling.