Comparison test block suitable for ultrasonic flaw detection of aluminum alloy round ingot and its manufacturing method

Abstract

The invention discloses a comparative test block and a manufacturing method suitable for ultrasonic flaw detection of aluminum alloy round ingots. The test block is stepped and has several different diameter sections. Several alumina balls are spaced apart on each diameter section, and the deviation between the center of each alumina ball and the axis is within 10 mm. There are three diameters of the alumina balls, namely 1.2 mm, 2.0 mm, and 3.2 mm. On the three diameter sections, there are alumina balls of Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm arranged in sequence, and the interval between two adjacent alumina balls is 60-70 mm. The manufacturing method uses electromagnetic stirring semi-continuous casting technology to prepare aluminum alloy round ingots. During the preparation process, alumina balls of different sizes are added in stages as artificial defects. The alumina balls are distributed to the core of the ingot under the action of electromagnetic stirring force. After the semi-continuous casting process is completed, the prepared ingots are processed into circular stepped test blocks of different diameters, which can be used as comparative test blocks for ultrasonic flaw detection of round ingots.

Description

Technical Field

[0001] The invention belongs to the field of ultrasonic flaw detection comparison test block manufacturing, and relates to a manufacturing method for an ultrasonic flaw detection comparison test block suitable for an aluminum alloy round ingot. Background Art

[0002] Aluminum alloy round ingots are generally prepared by semi-continuous casting. Ingots usually contain defects such as oxide inclusions, pores, and coarse intermetallic compounds. These defects have a certain volume. Defects exceeding a certain size will affect multiple properties of the ingot after subsequent plastic processing. However, the ultrasonic flaw detection of ingots and the comparison test blocks used are currently based on the flaw detection standards of deformed metals such as forging billets and extrusion billets. Flat-bottom holes are used as artificial defects. In the actual preparation process, flat-bottom holes of different sizes are processed on the ingot. This type of flat-bottom hole test block is difficult to process, and the flat-bottom hole is an area defect, which is very different from the volume defect morphology in the ingot, which is not conducive to the accurate determination of the size of the defect in the ingot. Therefore, it is necessary to invent a comparison test block that can better reflect the defects in the ingot and a convenient and reliable preparation method. Summary of the invention

[0003] The purpose of the present invention is to solve the above technical problems and provide a comparison test block and a production method suitable for ultrasonic flaw detection of aluminum alloy round ingots, so as to solve the problem that there are no appropriate comparison test blocks and national standards for ultrasonic flaw detection of aluminum alloy round ingots, and better reflect the defects in the ingots.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A comparative test block for ultrasonic flaw detection of aluminum alloy round ingots is in a stepped shape with a plurality of different diameter sections. A plurality of alumina balls are distributed at intervals on each diameter section, and the deviation between the center of each alumina ball and the axis is within 10 mm.

[0006] Preferably, the diameters of the alumina balls are of three types, namely 1.2mm, 2.0mm and 3.2mm. In the three diameter segments, there are one alumina ball of Φ1.2mm, one alumina ball of Φ2.0mm and one alumina ball of Φ3.2mm arranged in sequence, and the interval between two adjacent alumina balls is 60-70mm.

[0007] Preferably, the center of each alumina ball is aligned with the axis, and the interval between two adjacent alumina balls is 60 mm.

[0008] Preferably, the lengths of the small diameter section, the middle diameter section and the large diameter section are all 180 mm.

[0009] A method for making a comparison test block suitable for ultrasonic flaw detection of aluminum alloy round ingots, characterized in that:

[0010] Step 1: First, three Φ1.2 mm, three Φ2.0 mm, and three Φ3.2 mm spherical alumina ball particles are prepared as artificial defects in the test block, and then an electromagnetic stirring semi-continuous casting process is used to prepare an aluminum alloy round ingot;

[0011] Step 2: During the electromagnetic stirring semi-continuous casting process, when the melt flows into the crystallizer and gradually moves downward with the traction mechanism to form an ingot, the semi-continuous casting speed is controlled within the range of 30 to 50 mm / min, and the time interval is controlled within the range of 1.2 to 2 minutes to sequentially put a Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm alumina ball into the hot top until all 9 alumina balls are put in. According to the ingot specifications, the stirring frequency is controlled to be 3 to 10 Hz, and the stirring current is controlled to be within the range of 20 to 40 A, so that the melt in the crystallizer rotates under the action of the electromagnetic stirring force, and the melt rotates at a speed of 2 to 7 rpm. The alumina ball gradually moves to the axis position of the ingot as the metal melt rotates.

[0012] Step 3: After the semi-continuous casting is completed, the ingot is subjected to homogenization annealing to make the heat treatment state of the ingot consistent with the heat treatment state of the ingot to be inspected, the deviation between the center of each alumina ball in the ingot and the axis is within 10mm, and the distance between two alumina ball particles is 60-70mm, and alumina balls of Φ1.2mm, Φ2.0mm, and Φ3.2mm are distributed in sequence;

[0013] Step 4: Remove the outer skin of the round ingot, use an ultrasonic flaw detector to determine the exact position of the alumina balls in the round ingot, and then process the round ingot into three stepped round ingots with different diameters D. The length of each step L is 180 mm, and each step contains a spherical alumina ball of Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm.

[0014] The specification of the aluminum alloy ingot is Φ500mm, the electromagnetic stirring frequency used is 5Hz, the stirring current is 25A, and the semi-continuous casting speed is 40mm / min. During the casting process, spherical alumina ball particles are put into the hot top in three stages. In each stage, a spherical alumina ball of Φ1.2mm, Φ2.0mm, and Φ3.2mm is put in turn. The time interval between the inputs is 1.5min, so that the alumina balls are distributed along the axis of the ingot, and the distance between two spherical alumina ball particles is 60mm.

[0015] The beneficial effects of the present invention are as follows: the present invention uses alumina balls as embedded defects in the test block, and uses electromagnetic stirring semi-continuous casting technology to make the alumina balls evenly spaced and distributed in the core of the ingot. The preparation method is simple and can be applied to ultrasonic testing of alloy ingots of different sizes and specifications and different grades. The test block prepared by this method has the same material and organizational state as the ingot to be tested, and the embedded defects are equivalent to the actual defect type in the ingot, which is conducive to accurately determining the actual size of the defect in the ingot. The test block structure of the present invention is closer to the real defect and easier to prepare. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiment of the present invention, the embodiment will be described below with reference to the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the structure of a round ingot ultrasonic flaw detection comparison test block of the present invention;

[0018] Figure 2 yes Figure 1 Right view of . DETAILED DESCRIPTION

[0019] The following examples are merely used to illustrate possible implementations of the present invention, but are not intended to limit the scope of the present invention, so it is necessary to explain them first.

[0020] like Figure 1 and Figure 2 As shown, it is a preferred embodiment of the present invention, a comparative test block for ultrasonic flaw detection of aluminum alloy round ingots, the test block 1 is stepped, with three different diameter sections, and alumina balls 21 with a diameter of 1.2mm, alumina balls 22 with a diameter of 2.0mm, and alumina balls 23 with a diameter of 3.2mm are evenly distributed on each diameter section, and the deviation between the center of each alumina ball and the axis is within 10mm. Φ1.2mm, Φ2.0mm, and Φ3.2mm are commonly used size defects in the flaw detection industry.

[0021] Preferably, the center of the alumina ball is aligned with the axis, and the interval between two adjacent alumina balls is 60-70 mm, preferably 60 mm, mainly because the two defects cannot be too close to each other, because they are difficult to distinguish during flaw detection, and the size of the test block will be too large if they are too far away. The lengths of the small diameter section 11, the medium diameter section 12 and the large diameter section 13 are all 180 mm.

[0022] The following is a detailed description of a method for making a comparative test block suitable for ultrasonic flaw detection of aluminum alloy round ingots of the present invention.

[0023] Step 1: First, three Φ1.2 mm, three Φ2.0 mm, and three Φ3.2 mm spherical alumina ball particles are prepared as artificial defects in the test block, and then an electromagnetic stirring semi-continuous casting process is used to prepare an aluminum alloy round ingot;

[0024] Step 2: During the electromagnetic stirring semi-continuous casting process, when the melt flows into the crystallizer and gradually moves downward with the traction mechanism to form an ingot, the semi-continuous casting speed is controlled within the range of 30 to 50 mm / min, and the time interval is controlled within the range of 1.2 to 2 minutes to sequentially put a Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm alumina ball into the hot top until all 9 alumina balls are put in. According to the ingot specifications, the stirring frequency is controlled to be 3 to 10 Hz, and the stirring current is controlled to be within the range of 20 to 40 A, so that the melt in the crystallizer rotates under the action of the electromagnetic stirring force, and the melt rotates at a speed within the range of 2 to 7 rpm. The alumina ball gradually moves to the axis centerline position of the ingot as the metal melt rotates;

[0025] Step 3: After the semi-continuous casting is completed, the ingot is homogenized and annealed to make the heat treatment state of the ingot consistent with that of the ingot to be inspected. The deviation between the center and the axis of each alumina ball in the ingot is within 10mm, and the distance between two alumina ball particles is 60-70mm, with alumina balls of Φ1.2mm, Φ2.0mm, and Φ3.2mm distributed in sequence;

[0026] Step 4: Remove the outer skin of the round ingot, use an ultrasonic flaw detector to determine the exact position of the alumina balls in the round ingot, and then process the round ingot into three stepped round ingots with different diameters D. The length of each step L is 180 mm, and each step contains a spherical alumina ball of Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm.

[0027] Specifically, taking the preparation of Φ500mm aluminum alloy ingot as an example, the semi-continuous casting speed is 40mm / min, the electromagnetic stirring frequency used in the casting process is 5Hz, the stirring current is 25A, and the electromagnetic stirring makes the melt rotate at a speed of 3 rpm. During the casting process, alumina ball particles are added to the hot top in three stages. In each stage, a spherical alumina ball of Φ1.2mm, Φ2.0mm, and Φ3.2mm is added in turn. The time interval between the additions is 1.5min, so that the distance between the two spherical alumina ball particles is about 60mm.

[0028] Step three, after the semi-continuous casting is completed, the ingot is subjected to homogenization annealing, and the center of the obtained round ingot is distributed with alumina balls of Φ1.2mm, Φ2.0mm, and Φ3.2mm at intervals of 60mm.

[0029] Step 4: Remove the outer skin of the round ingot, use an ultrasonic flaw detector to determine the exact position of the alumina balls in the round ingot, and then process the round ingot into stepped round ingots with diameters of Φ460mm, Φ360mm, and Φ260mm, respectively. The length of each step L is 180mm, and each step contains a spherical alumina ball of Φ1.2mm, Φ2.0mm, and Φ3.2mm.

[0030] In the specific implementation process, during the semi-continuous casting process, the electromagnetic force of the melt is controlled to make the melt rotate at a certain speed, so that the alumina balls put into the crystallizer can be moved to the axis position of the ingot; keeping the semi-continuous casting speed unchanged and controlling the time interval of putting alumina balls into the melt, the intervals between the balls can be made basically consistent.

[0031] The round ingot ultrasonic flaw detection comparison test block, when actually testing the round ingot, uses the reflected wave of the cylindrical surface test alumina ball of corresponding diameter as the defect judgment standard to determine the flaw detection sensitivity when testing the workpiece to be tested. When a defect reflected wave appears in the workpiece to be tested, the equivalent value of the defect size of the workpiece to be tested can be obtained by comparing the reflected wave of the defect in the workpiece to be tested with the reflected wave in the comparison test block, thereby judging whether the defect exceeds the standard.

Claims

1. A method for making a comparison test block suitable for ultrasonic flaw detection of aluminum alloy round ingots, characterized in that: Step 1: First, three Φ1.2 mm, three Φ2.0 mm, and three Φ3.2 mm spherical alumina ball particles are prepared as artificial defects in the test block, and then an electromagnetic stirring semi-continuous casting process is used to prepare an aluminum alloy round ingot; Step 2, during the electromagnetic stirring semi-continuous casting process, when the melt flows into the crystallizer and gradually moves downward with the traction mechanism to form an ingot, the semi-continuous casting speed is controlled within the range of 30-50 mm / min, and the time interval is controlled within the range of 1.2-2 minutes to sequentially put an alumina ball of Φ1.2 mm, Φ2.0 mm, Φ3.2 mm, Φ1.2 mm, Φ2.0 mm, Φ3.2 mm, Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm into the hot top until all 9 alumina balls are put in. According to the ingot specifications, the stirring frequency is controlled to be 3-10 Hz, and the stirring current is controlled to be within the range of 20-40 A, so that the melt in the crystallizer rotates under the action of the electromagnetic stirring force, and the melt rotates at a speed within the range of 2-7 rpm. The alumina ball gradually moves to the axis position of the ingot as the metal melt rotates; Step 3: After the semi-continuous casting is completed, the ingot is subjected to homogenization annealing to make the heat treatment state of the ingot consistent with the heat treatment state of the ingot to be inspected, the deviation between the center of each alumina ball in the ingot and the axis is within 10mm, the distance between two alumina ball particles is 60-70mm, and alumina balls of Φ1.2mm, Φ2.0mm, and Φ3.2mm are distributed in sequence; Step 4: Remove the outer skin of the round ingot, use an ultrasonic flaw detector to determine the exact position of the alumina ball in the round ingot, and then process the round ingot into three stepped round ingots with different diameters D. The length of each step L is 180 mm, and each step contains a spherical alumina ball of Φ1.2 mm, Φ2.0 mm, and Φ3.2 mm.

2. The method for making a comparative test block suitable for ultrasonic flaw detection of aluminum alloy round ingots according to claim 1 is characterized in that: The specification of the aluminum alloy ingot is Φ500mm, the semi-continuous casting speed is 40mm / min, the electromagnetic stirring frequency is 5Hz, the stirring current is 25A, and the electromagnetic stirring makes the melt rotate at a speed of 3 rpm. An alumina ball of Φ1.2mm, Φ2.0mm, Φ3.2mm, Φ1.2mm, Φ2.0mm, Φ3.2mm, Φ1.2mm, Φ2.0mm, and Φ3.2mm is put in sequence with a time interval of 1.5min, so that the alumina balls are distributed along the axis of the ingot, and the alumina ball particles are distributed at equal intervals.

3. The method for making a comparative test block suitable for ultrasonic flaw detection of aluminum alloy round ingots according to claim 1 is characterized in that: The alumina balls are distributed along the axis of the ingot, and adjacent alumina balls are equally spaced.

4. The method for making a comparative test block suitable for ultrasonic flaw detection of aluminum alloy round ingots according to claim 1, characterized in that: The lengths of the small diameter section, the middle diameter section and the large diameter section are all 180 mm.

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