A method for measuring a protective slag layer

Abstract

The application discloses a kind of protective slag layer measuring methods, and the slag rod is inserted into high carbon steel liquid after passing through protective slag layer, and the thickness of protective slag layer in high carbon steel liquid is measured by the state of particle adhered on the slag rod and the length of slag rod inserted into molten steel.The application provides a kind of protective slag layer measuring method, which is simple in equipment and easy to operate, and has small measurement error, solves the problem that the total thickness of protective slag and the thickness of liquid slag layer cannot be accurately measured during high carbon steel continuous casting, improves the stability during high carbon steel pouring process, and improves the quality of high carbon steel billet.

Description

TECHNICAL FIELD

[0001] The present application relates to Steelmaking TECHNICAL FIELD, in particular to a kind of protective slag layer measurement method. BACKGROUND

[0002] The commonly used method for measuring liquid slag layer thickness in industrial production is to insert a combination of steel wire and copper wire (or aluminum wire) into the slag layer of crystallizer, the copper wire melts, and the length of the melted copper wire is measured as the liquid slag layer thickness. Since the liquidus temperature of high-carbon steel is low, the corresponding protective slag melting point is also low. The steel wire in the traditional measurement method does not melt in the high-carbon steel liquid, and the copper wire does not melt in the protective slag. Therefore, the traditional method cannot be applied to the measurement of high-carbon steel slag layer. Other protective slag measurement methods, such as by increasing lifting, radar, computer processing and other devices, are too complex and cannot be applied on site. SUMMARY

[0003] In view of the above problems, the present application is proposed to provide a protective slag layer measurement method to overcome the above problems or at least partially solve the above problems.

[0004] The present application provides a protective slag layer measurement method, comprising: inserting a slag measuring rod into high-carbon steel liquid after passing through the protective slag layer, so that the surface of the protective slag layer coincides with a mark line on the slag measuring rod;

[0005] After maintaining for a set time, melting the end of the slag measuring rod inserted into the high-carbon steel liquid, and taking out the slag measuring rod;

[0006] According to the length of the mark line to the melted end of the slag measuring rod, determining the total thickness of the protective slag layer;

[0007] According to the length of the molten protective slag adhered on the slag measuring rod, determining the thickness of the liquid slag layer in the protective slag layer;

[0008] According to the length of the solid particle layer adhered on the slag measuring rod, determining the thickness of the sintered layer in the protective slag layer;

[0009] According to the length of the mark line to the junction of the original layer on the slag measuring rod and the adhered solid particle layer, determining the thickness of the powder slag layer in the protective slag layer;

[0010] The total thickness of the protective slag layer is the sum of the thickness of the powder slag layer, the thickness of the sintered layer and the thickness of the liquid slag layer.

[0011] Optionally, when the slag measuring rod is inserted into the high-carbon steel liquid after passing through the protective slag layer, the included angle between the slag measuring rod and the surface of the protective slag layer is 80°-90°.

[0012] Optionally, it further comprises:

[0013] According to the length between the mark line on the measuring slag stick and the powder slag layer, the thickness of the sintered layer of the protective slag layer is determined.

[0014] Optionally, the keeping to the set time is 3-10 seconds.

[0015] Optionally, the equivalent diameter of the measuring slag stick is 1-10 mm.

[0016] Optionally, the equivalent diameter of the measuring slag stick is less than 5 mm, and the keeping to the set time is 3-6 seconds; the equivalent diameter of the measuring slag stick is 5-10 mm, and the keeping to the set time is 6-10 seconds.

[0017] Optionally, the length of the measuring slag stick is 150-300 mm.

[0018] Optionally, the melting point of the measuring slag stick is 1200-1400 DEG C.

[0019] Optionally, the material of the measuring slag stick is iron-aluminum alloy, and the mass percentage of aluminum in the iron-aluminum alloy is 10%-42%.

[0020] Optionally, the length of the mark line is greater than 1 mm.

[0021] The technical scheme provided in the embodiments of the present application has at least the following technical effects or advantages:

[0022] The protective slag layer measuring method provided in the embodiments of the present application directly measures the thickness of the protective slag and the liquid slag layer by using a measuring slag stick, and has simple equipment, simple operation, small measurement error, solves the problem that the total thickness of the protective slag and the thickness of the liquid slag layer cannot be accurately measured in the high-carbon steel continuous casting process, improves the stability in the high-carbon steel pouring process, and improves the quality of the high-carbon steel cast slab.

[0023] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of preferred embodiments, and are not meant to limit the present application. Furthermore, the same reference numerals are used throughout the several drawings to represent similar components. In the drawings:

[0025] Figure 1A process schematic diagram of the protective slag layer measurement method in the embodiment of the present application;

[0026] Figure 2 A schematic diagram of the measuring slag rod; DETAILED DESCRIPTION

[0027] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings.

[0028] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These diagrams are not drawn to scale, in which certain details are exaggerated for the purpose of clarity, and certain details can be omitted. The shapes of various regions, layers shown in the diagrams, and their relative sizes and positional relationships are merely exemplary, and in actuality, they can deviate due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes, relative positions can be additionally designed by those skilled in the art according to actual needs.

[0029] In the context of the present disclosure, when a layer / element is referred to as being located "on" another layer / element, the layer / element can be directly located on the other layer / element, or there can be an intervening layer / element therebetween. In addition, if a layer / element is located "on" another layer / element in one orientation, it can be located "under" the other layer / element when the orientation is reversed. In the context of the present disclosure, similar or identical components can be indicated by the same or similar reference numerals.

[0030] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with specific embodiments. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, and not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0031] The present application provides a protective slag layer measurement method, as shown in Figure 1 Figure 1 A process schematic diagram of the protective slag layer measurement method in the embodiment of the present application, comprising:

[0032] S1, inserting the measuring slag rod into the high-carbon steel liquid after passing through the protective slag layer, so that the surface of the protective slag layer coincides with the mark line on the measuring slag rod;

[0033] S2, after maintaining for a set time, melting the end of the measuring slag rod inserted into the high-carbon steel liquid, and taking out the measuring slag rod;

[0034] S3, judging the total thickness of the protective slag layer according to the length of the mark line to the melted end of the measuring slag rod; ​

[0035] S4, judging the thickness of the liquid slag layer in the protective slag layer according to the length of the molten state protective slag adhered on the measuring slag rod;

[0036] S5, judging the thickness of the sintered layer in the protective slag layer according to the length of the solid particle layer adhered on the measuring slag rod;

[0037] S6, judging the thickness of the powder slag layer in the protective slag layer according to the length of the marking line to the junction of the original layer on the measuring slag rod and the adhered solid particle layer; the total thickness of the protective slag layer is the sum of the thickness of the powder slag layer, the thickness of the sintered layer and the thickness of the liquid slag layer.

[0038] The protective slag is added into the high-carbon steel liquid in the crystallizer, and forms a three-layer structure of liquid slag layer, sintered layer and powder slag layer under the action of heat exchange with the steel liquid. After the measuring slag rod is inserted into the high-carbon steel liquid, a visible protective slag particle adhered layer is formed on the surface of the measuring slag rod; at the same time, the measuring slag rod can be melted in the high-carbon steel liquid, and the liquid slag layer can also be obviously distinguished. The thickness of the three-layer slag structure affects the degree of air isolation of the steel liquid surface, the initial formation of the meniscus blank shell, the protective slag agglomeration and slag strip, the absorption and dissolution of non-metallic inclusions, the lubrication of the crystallizer wall and the blank shell. The part of the measuring slag rod inserted into the high-carbon steel liquid is melted, so the thickness of the protective slag layer can be judged according to the length of the marking line to the melted part of the measuring slag rod. As shown in FIG. 2, the total thickness of the protective slag layer is judged according to the length of the marking line to the remaining part of the measuring slag rod which is not melted. The thickness of the powder slag layer in the protective slag layer is judged according to the length of the marking line to the junction of the original layer on the measuring slag rod and the adhered solid particle layer. The thickness of the sintered layer in the protective slag layer is judged according to the length of the solid particle layer adhered on the measuring slag rod. The thickness of the liquid slag layer in the protective slag layer is judged according to the length of the molten state protective slag adhered on the measuring slag rod. The total thickness of the protective slag layer = the thickness of the powder slag layer + the thickness of the sintered layer + the thickness of the liquid slag layer. Figure 2 Specifically, the length of the marking line to the melted end of the measuring slag rod in step S3 refers to the length of the marking line to the junction line between the melted end and the unmelted end of the measuring slag rod.

[0039] Specifically, the original layer in step S4 refers to the part of the rod body of the measuring slag rod inserted into the protective slag layer and not adhering particles, and the length of the marking line to the junction of the original layer on the measuring slag rod and the adhered solid particle layer refers to the length of the marking line to the junction of the part of the rod body of the measuring slag rod inserted into the protective slag layer and not adhering particles and the sintered layer of the adhered solid particle layer, that is, the length of the part of the rod body of the measuring slag rod inserted into the protective slag layer and not adhering particles.

[0040]

[0041] ​In an optional embodiment, the angle between the measuring slag stick and the surface of the protective slag layer is 80-90 degrees when the measuring slag stick is inserted into the high-carbon steel liquid after being passed through the protective slag layer in step S1. If the angle between the measuring slag stick and the surface of the protective slag layer is too small, the measurement error of the thickness of the slag layer will be large. Specifically, the measuring slag stick is vertically inserted into the high-carbon steel liquid, which is most conducive to improving the accuracy of the measurement of the thickness of the slag layer.

[0042] Step S1 needs to be performed after the high-carbon steel liquid in the crystallizer reaches a stable state. When the state of the crystallizer is unstable, the thicknesses of the liquid slag layer, the sintered layer, the powder slag layer and the total slag layer in the protective slag change with time, and the measurement values cannot represent the true data of the protective slag layer.

[0043] In an optional embodiment, the set time in step S2 is 3-10 seconds. If the measuring slag stick stays in the crystallizer for too short a time, the measuring slag stick cannot be melted in the steel liquid, and the thickness of the slag layer cannot be measured. If the measuring slag stick stays in the crystallizer for too long, the accuracy of the measurement of the thickness of the slag layer will be affected.

[0044] In an optional embodiment, the equivalent diameter of the measuring slag stick is 1-10 mm. Specifically, if the equivalent diameter of the measuring slag stick is less than 5 mm, the measuring slag stick stays in the crystallizer for 3-6 seconds in step S2. If the equivalent diameter of the measuring slag stick is 5-10 mm, the measuring slag stick stays in the crystallizer for 6-10 seconds in step S2.

[0045] In an optional embodiment, the length of the marking line is greater than 1 mm. The position of the marking line can be better distinguished.

[0046] In an optional embodiment, the equivalent diameter of the measuring slag stick is 1-10 mm. If the equivalent diameter of the measuring slag stick is too large, the melting time of the measuring slag stick in the high-carbon steel liquid is long, and the accuracy of the measurement result will be affected.

[0047] In an optional embodiment, the length of the measuring slag stick is 150-300 mm. If the length of the measuring slag stick is too long, the on-site operation is limited, and the measurement cannot be accurately performed. If the length of the measuring slag stick is too short, the on-site operation is difficult.

[0048] In an optional embodiment, the melting point of the measuring slag stick is 1200-1400℃. The melting point of the high-carbon steel is usually between 1400-1500℃, and the melting temperature of the liquid slag layer is about 800-1100℃. The melting point of the measuring slag stick needs to be between the high-carbon steel and the liquid slag layer, so that the part of the measuring slag stick inserted into the high-carbon steel liquid can be melted in the high-carbon steel liquid, thereby facilitating the observation of the demarcation line between the molten protective slag and the solid particle layer protective slag on the measuring slag stick, and further measuring the total thickness of the protective slag layer and the thickness of the liquid slag layer. If the melting point of the measuring slag stick is too high, the measuring slag stick cannot be melted in the high-carbon steel liquid, and the thickness of the protective slag layer cannot be measured. If the melting point is too low, the measuring slag stick is easily melted in the liquid slag layer, and the thickness of the liquid slag layer cannot be measured.

[0049] In an optional embodiment, the material of the slag measuring rod is iron-aluminum alloy, the mass percentage of aluminum in the iron-aluminum alloy is 10% to 42%, and the mass percentage of iron in the iron-aluminum alloy is 58% to 90% correspondingly.

[0050] The high-carbon steel protective slag layer thickness measuring method of the present application is described in detail below with specific examples, comparative examples and experimental data.

[0051] The specific operations of the examples and the comparative examples are as follows:

[0052] After the high-carbon steel liquid in the crystallizer reaches a stable state, a mark line is made on the slag measuring rod, S1 is performed, the slag measuring rod is inserted into the high-carbon steel liquid after passing through the protective slag layer at a set angle (the measuring angle in Table 1 below), and the surface of the protective slag layer is overlapped with the mark line on the slag measuring rod;

[0053] S2 is performed, the end of the slag measuring rod inserted into the high-carbon steel liquid is melted after being kept for a set time, and the slag measuring rod is taken out;

[0054] S3 is performed, the total thickness of the protective slag layer is determined according to the length from the mark line to the melted end of the slag measuring rod;

[0055] S4 is performed, the thickness of the liquid slag layer in the protective slag layer is determined according to the length of the molten protective slag adhered to the slag measuring rod;

[0056] S5 is performed, the thickness of the sintered layer in the protective slag layer is determined according to the length of the solid particle layer adhered to the slag measuring rod;

[0057] S6 is performed, the thickness of the powder slag layer in the protective slag layer is determined according to the length from the mark line to the junction of the original layer on the slag measuring rod and the adhered solid particle layer, and the total thickness of the protective slag layer is the sum of the thickness of the powder slag layer, the thickness of the sintered layer and the thickness of the liquid slag layer.

[0058] The process parameter list of each example and each comparative example is shown in Table 1 below.

[0059]

[0060] Table 1 Process parameter list of examples and comparative examples

[0061] From the data in Table 1, it can be seen that:

[0062] In Examples 1-3, the technical solution given by the measuring method of the present application is adopted, the liquid slag layer, the sintered layer, the powder slag layer and the total slag layer thickness of the protective slag on the surface of the high-carbon steel liquid in the crystallizer are directly measured by the slag measuring rod made of iron-aluminum alloy.

[0063] In the comparative example 1, the thickness of the slag layer of the high-carbon steel is measured by using the steel rod, and since the melting point of the steel rod is 1510 DEG C, the steel rod does not melt in the high-carbon steel liquid, and the thickness of the slag layer is not measured.

[0064] In the comparative example 2, the length of the steel rod is too short, and the thickness of the slag layer cannot be measured in the field operation.

[0065] In the comparative example 3, the steel rod is too thick, the measurement of the slag rod melts in the high-carbon steel liquid for a long time, and the measurement error is large.

[0066] In the comparative example 4, the angle between the slag rod and the slag surface is small, and the error is large in the measurement process.

[0067] In the comparative example 5, the slag rod remains in the crystallizer for a short time, the slag rod does not melt in the steel liquid, and the thickness of the slag layer cannot be measured.

[0068] The technical scheme provided in the embodiment of the present application has at least the following technical effects or advantages: the slag rod is used to directly measure the thickness of the liquid slag layer, the sintered layer, the powder slag layer and the total slag layer of the protective slag on the surface of the high-carbon steel liquid in the crystallizer, the device is simple, the operation is simple, the measurement error is small, the problem that the total thickness of the protective slag and the thickness of the liquid slag layer cannot be accurately measured in the continuous casting process of the high-carbon steel is solved, the stability in the pouring process of the high-carbon steel is improved, and the quality of the high-carbon steel casting blank is improved.

[0069] The protective slag layer measurement method provided by the present application directly measures the total thickness of the protective slag, the liquid slag layer and the powder slag layer of the high-carbon steel liquid by using the slag rod. The device is simple, the operation is simple, the measurement error is small, the problem that the total thickness of the protective slag and the thickness of the liquid slag layer cannot be accurately measured in the continuous casting process of the high-carbon steel is solved, the stability in the pouring process of the high-carbon steel is improved, and the quality of the high-carbon steel casting blank is improved.

[0070] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some examples, well-known measurement methods, structures and techniques are not shown in detail, so as not to obscure the understanding of the present specification.

[0071] Similarly, it is to be understood that the teachings of the present application can be used in a variety of applications. Accordingly, the terminology and phraseology employed above are used for the purpose of description and not of limitation. Thus, claims can be pursued subject to applicable law without restriction regarding equivalency, except to the extent that equivalents per se are expressly surrendered by statutory language of the claims.

[0072] It is to be understood that the embodiments of the present application that have been described are merely illustrative of the many applications of the principles of the present application. Numerous modifications can be made to the illustrative embodiments, and other implementations of the present application can be used without departing from the spirit and scope of the present application. For example, the above-described embodiments can be implemented in hardware, software, or a combination thereof. The various steps or acts in a method can be carried out in more or fewer than can be shown. Additionally, one or more steps or acts can be carried out by special purpose hardware-based computer systems which are designed to carry out program tasks. Note also that the examples given above are the most practical and preferred implementations of the application, although those skilled in the art will understand that many modifications can be made without departing from the spirit and scope of the application. Accordingly, the above description is not intended as limiting of the scope of the application. It is not intended to limit the scope or practice of the application presented herein to the expressly claimed aspects. Many modifications and variations will be apparent to those of ordinary skill in the art upon reading this description. It is therefore understood that within the scope of the appended claims, the application can be practiced otherwise than is specifically described herein. For further explanation, reference is made to the eartiest claims as indicative thereof. The patentable scope of the application is defined by the claims, and can include modifications apparent to those skilled in the art to which the present application pertains. It is therefore intended that this patent application be interpreted by spirt and scope of the appended claims and not astrictly by procedure of the prior art.

Claims

1. A method of measuring a protective slag layer, characterized by, The method comprises the following steps: inserting a slag measuring rod into high-carbon steel liquid through a protective slag layer, so that the surface of the protective slag layer coincides with a mark line on the slag measuring rod; melting the end of the slag measuring rod inserted into the high-carbon steel liquid after keeping for a set time, and taking out the slag measuring rod; judging the total thickness of the protective slag layer according to the length of the mark line to the melted end of the slag measuring rod; judging the thickness of a liquid slag layer in the protective slag layer according to the length of the molten protective slag adhered to the slag measuring rod; judging the thickness of a sintered layer in the protective slag layer according to the length of the solid particle layer adhered to the slag measuring rod; judging the thickness of a powder slag layer in the protective slag layer according to the length of the mark line to the junction of the original layer of the slag measuring rod and the adhered solid particle layer; the total thickness of the protective slag layer is the sum of the thickness of the powder slag layer, the thickness of the sintered layer and the thickness of the liquid slag layer; the melting point of the slag measuring rod is 1200-1400℃; the material of the slag measuring rod is iron-aluminum alloy, and the mass percentage of aluminum in the iron-aluminum alloy is 10%-42%; the melting point of the high-carbon steel is between 1400℃ and 1500℃, the temperature of the liquid slag layer is between 800℃ and 1100℃, and the melting point of the slag measuring rod is between the melting point of the high-carbon steel and the temperature of the liquid slag layer.

2. The measurement method of claim 1, wherein, the equivalent diameter of the slag measuring rod is 1-10mm.

3. The measurement method of claim 1, wherein, the keeping for a set time is 3-10 seconds.

4. The measurement method according to claim 1 or 3, characterized in that, when the equivalent diameter of the slag measuring rod is less than 5mm, the keeping for a set time is 3-6 seconds; when the equivalent diameter of the slag measuring rod is 5-10mm, the keeping for a set time is 6-10 seconds.

5. The measurement method of claim 1, wherein, when the slag measuring rod is inserted into the high-carbon steel liquid through the protective slag layer, the included angle between the slag measuring rod and the surface of the protective slag layer is 80°-90°.

6. The measurement method of claim 1, wherein, the length of the slag measuring rod is 150-300mm.

7. The method of measuring of claim 1, wherein, the length of the mark line is greater than 1mm.

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