JPH0676861U - Probe for measuring the solidification temperature of molten metal - Google Patents

Abstract

(57) [Summary] [Purpose] A new molten metal solidification that achieves the effects of lower manufacturing costs, lower tar generation, and lighter weight, while maintaining the same performance as a metal sampling mold. Providing temperature measurement probe. [Structure] A solidification temperature of molten metal, characterized in that the sampling mold includes an inflow port, a partition, and a sample chamber made of foundry sand, and the diameter and the length of the partition and the sample chamber are within specific ranges. Measuring probe.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a probe for estimating the amount of carbon in molten metal by immersing it in molten metal with a converter sublance, sampling the molten metal, and measuring the solidification temperature of the sample. Is.

[0002]

[Prior art]

 Conventionally, in converters, which have been the core of the steelmaking process for steel, the temperature, solidification temperature, oxygen content, etc. are measured with a consumable probe using a sublance, and the end point control and end point temperature are determined by a dynamic control system.・ Confirmation of ingredients is being conducted. All of these measurements have recently been particularly required to be quick and accurate. An example of a conventional sublance probe is shown in FIG. In FIG. 2, a solidification temperature sensor 5 composed of a thermocouple is provided at the bottom of the metal sample chamber 10. A sensor 7 for measuring the temperature of molten steel is provided at the tip, and these are protected by a protective tube 2 made of paper. The probe is attached to the tip of the sublance, the contact point of the thermocouple is taken by the connector 8, the sublance is lowered, the probe is immersed in the molten steel, and the molten steel temperature is measured. A temperature curve as shown in Fig. 3 is obtained by measuring the temperature of the sample collected inside the sample, and the equilibrium part, that is, the solidification temperature is read to estimate the carbon content. .

[0003]

[Problems to be solved by the device]

 In order to increase the speed of solidification temperature measurement, conventionally, the material of the sample chamber is made of metal such as steel having a large thermal conductivity and a cooling capacity, which has a cooling ability. However, compared with casting sand, which has low thermal conductivity and low cooling capacity, metal was more expensive. Also, since the molten steel flows into the sample chamber due to its high thermal conductivity, the heat of the sample raises the temperature of the sample chamber, baking the paper tube around the sample chamber and generating tar from the paper tube. Due to the tar, there was a defect that the electrical insulation resistance of the connector at the tip of the sublance was lowered, resulting in measurement failure or an increase in the frequency of connector replacement. Moreover, since the specific gravity is large, the probe becomes heavy, and there is a drawback that the handling such as transportation is burdened.

Further, during immersion, the protective tube made of paper and molten steel react with each other, so that the probe vibrates violently, and the sample in the upper part of the sample chamber jumps out before solidifying, resulting in a small sample volume and equilibrium. There was also a drawback that the length of the section became too short or varied.

In the measurement of the freezing point, the equilibrium portion start time shows the quickness of the measurement, and the shorter the equilibrium portion start time, the better. However, there are various molten steel conditions (molten steel temperature and solidification temperature) at the probe immersion timing. The higher the molten steel temperature, the larger the heat capacity of the sample to be sampled, and the slower the equilibrium part start time. Also, the larger the difference between the molten steel temperature and the solidification temperature, the more the equilibrium part start time becomes slower. Also, the equilibrium section length time may be longer than the solidification temperature can be read (several seconds), but like the equilibrium section start time, it varies depending on the molten steel conditions. Tends to be short. In addition, if the start time of the equilibrium portion is increased, the length time of the equilibrium portion tends to be shorter, and vice versa.

As described above, both the equilibrium portion start time and the equilibrium portion length time change depending on the molten steel conditions, and because of the above relationship between the two, the equilibrium portion start time is 5 seconds or less on average. The equilibrium length is preferably 10 seconds or longer.

An object of the present invention is to provide an inexpensive probe for measuring the solidification temperature, which is capable of performing a quick measurement similar to that of a metallic material, while using the molding sand as the material of the sample chamber. .

[0008]

[Issues to be solved by the device]

 The inventors of the present invention prevent the variation of the measurement result due to the jumping out of the sample during measurement by providing the partition part, and make the diameter and the length of the partition part and the sample chamber into a specific range to achieve a preferable equilibrium. The present invention has been completed by finding that the start time of the section and the length of the equilibrium section can be obtained.

That is, the present invention is a probe for solidification temperature measurement comprising a protective tube, an inlet on the side surface of the protective tube, and a sampling mold for measuring the solidification temperature inside, and the sampling mold is made of foundry sand. Including an inlet, a partition, and a sample chamber, the partition has a diameter of 10 to 20 m / m, a length of 25 to 45 m / m, a diameter of the sample chamber of 23 to 27 m / m, and a length. A probe for measuring the solidification temperature of a molten metal is provided, which is characterized in that it is 30 to 40 m / m.

By using the above probe, performance equivalent to that of a metal sampling mold can be obtained without causing the above-mentioned problems.

FIG. 1 shows a configuration example of a probe according to the present invention. The sampling mold is made of foundry sand and is composed of an inlet 3a, a partition 3b and a sample chamber 3c, and a solidification temperature sensor 5 made of a thermocouple is provided at the bottom of the sample chamber 3c. A hole cover 6 is provided at the inlet 4 to prevent slag inflow and to keep the inflow timing constant. A molten steel temperature sensor 7 is provided at the tip of the probe 1, and a connector 8 is provided at the approximate center of the inside of the protective tube 2 made of paper.

[0012]

【Example】

 The diameter and length of the sample chamber and partition were changed, and the equilibrium section start time and equilibrium section length time were measured. The experiment was conducted 5 times under each condition, and the average value is shown in the table. The unit of the diameter and length of the sample chamber and the partition is mm.

Further, as a comparative example, the results of experiments in the case where the present invention is out of the range are also shown in the same table.

As is apparent from the table, when the probe according to the present invention is used, it is possible to obtain a short equilibrium part start time and a sufficiently long equilibrium part length time, which enables quick and accurate measurement.

[0015]

[0016]

[Effect of device]

 With the probe of the present invention, regarding the solidification temperature measurement, while maintaining the same performance as the metal sampling mold, it is possible to obtain the effects of lowering the manufacturing cost, reducing the amount of tar generation, and reducing the weight of the probe. Furthermore, it is now possible to collect a fixed volume of sample at all times, improving performance and stabilizing performance.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a probe according to the present invention.

FIG. 2 is a diagram showing a configuration of a conventional probe.

FIG. 3 is a diagram showing a change in measured temperature when measuring a solidification temperature.

[Explanation of symbols]

 1 Probe 2 Protective Tube 3a Inlet 3b Partition 3c Sample Chamber 4 Inlet 5 Solidification Temperature Sensor 6 Hole Cover 7 Molten Steel Temperature Sensor 8 Connector 9 Cast Sand 10 Metal Sample Chamber

Claims (1)

[Scope of utility model registration request] 1. A probe for measuring a solidification temperature, comprising a protective tube, an inlet on a side surface of the protective tube, and a sample-collecting mold for measuring a solidification temperature therein, wherein the sample-collecting mold is made of foundry sand. , A partition part and a sample chamber, the partition part has a diameter of 10 to 20 m / m, a length of 25 to 45 m / m, a sample chamber diameter of 23 to 27 m / m, and a length of 30 to 40 m / m. m is a probe for measuring the solidification temperature of molten metal.