A method for detecting internal defects of cemented carbide rolls

A cemented carbide and detection method technology, which is applied to measuring devices, instruments, and the use of sound waves/ultrasonic waves/infrasonic waves to analyze solids, etc., can solve problems such as unrepaired cracks, increased rolling costs, and inability to continue to use, so as to ensure quality Effect

Active Publication Date: 2021-04-23
ZHUZHOU HARD ALLOY GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It is difficult to judge the specific location of the defect by routine inspection, so it often causes great adverse consequences, such as: some cracks have extended to the inside of the roll, which cannot be used anymore, and grinding is not necessary; if the cracks are not repaired, especially There are cracks in the grooves and ribs of the ribbed roll, and the depth of the cracks is not the same, and it is impossible to grind the cracks. These cracks continue to expand during the rolling process, causing the roll to crack; these consequences seriously affect the quality of the steel and rolling. production efficiency, resulting in increased rolling costs or unnecessary waste
However, there is no ultrasonic testing method or related reports for cemented carbide slotted rolls and ribbed rolls so far, so it is of great significance to develop a detection method for internal defects of cemented carbide slotted rolls and ribbed rolls.

Method used

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  • A method for detecting internal defects of cemented carbide rolls
  • A method for detecting internal defects of cemented carbide rolls
  • A method for detecting internal defects of cemented carbide rolls

Examples

Experimental program
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Effect test

Embodiment 1

[0040] The invention provides a method for detecting internal defects of a cemented carbide roll, comprising the following steps:

[0041] (1) Taking the arc surface of the slotted roll as the testing surface, select 12 pieces of slotted rolls as testing samples, numbered 1 to 12, and make a comparison test block to ensure that the curvature of the comparison test block and the test sample are the same, specifically as follows figure 1 As shown, the phased array ultrasonic detector adopts omniscan MX2, uses a 16-chip probe with a frequency of 10MHz, and is equipped with a curved wedge that is the same or close to the internal curvature of the product to be tested, which facilitates good contact between the probe and the sample to be tested, and makes the ultrasonic Energy is more easily transferred to the interior of the sample;

[0042] (2) Set a section of iron wire arc with a length of 20-30mm inside the comparison test block, and use the method of spark punching to punch t...

Embodiment 2

[0048] The present invention provides a method for detecting internal defects of cemented carbide rolls. To detect cracks in grooves of ribbed rolls, 12 pieces of ribbed rolls are selected as test samples, numbered 13-24, using the same sensitivity and scanning as in Example 1. The detection method is carried out, and the detection results are shown in Table 2:

[0049] Table 2 Test results

[0050]

[0051] Image 6 It is the defect waveform diagram of No. 15 ribbed roll (158 / 87-62-¢10 screw). According to the waveform diagram, it can be concluded that the fatigue crack in the groove is 10mm deep, 12mm long, and 8mm after grinding. There are still fatigue cracks after grinding. , Figure 7 It is the defect waveform diagram of cracks still remaining after grinding of No. 15 ribbed roll, Figure 8 It is the physical picture of No. 15 ribbed roll after grinding.

Embodiment 3

[0053] The present invention provides a method for detecting internal defects of cemented carbide rolls. To detect cracks in the ribs of ribbed rolls, 12 pieces of ribbed rolls in Example 2 are used as test samples, numbered 25-36, and the same method as in Example 2 is used. The sensitivity and scanning method are used to detect ribbed rolls, and the test results are shown in Table 3:

[0054] Table 3 Test results

[0055]

[0056] Figure 9 It is the defect waveform diagram of No. 34 engraved ribbed roll (360 / 240-105-¢8 screw). According to the waveform diagram, it can be concluded that the crack in the rib is 34mm deep and 5mm long. It is unnecessary to regrind and it will be rejected directly. Figure 10 It is the physical picture of the crack inside the rib of No. 34 ribbed roll.

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Abstract

The invention discloses a method for detecting internal defects of a cemented carbide roll, belonging to the technical field of ultrasonic flaw detection, comprising the following steps: 1) selecting a cemented carbide roll as a test sample, making a comparison test block, and ensuring the accuracy of the comparison test block and the test sample The material is the same; 2) Concentric circular arc defects are set inside the comparison test block, and a number of holes and cracks are produced on the comparison test block, and the comparison test block is used to perform ACG, TCG correction and sensitivity adjustment of the phased array ultrasonic detector ;3) After the calibration of the instrument is completed, flaw detection is carried out on the inner arc surface of the cemented carbide roll to determine the specific location of the crack and determine the grinding plan. The method for detecting internal defects of cemented carbide rolls described in the present invention can quickly perform ultrasonic detection on cemented carbide slotted rolls and ribbed rolls, and can detect equivalent holes with an internal diameter of 0.3 mm for grooved and ribbed rolls, and can accurately Determine the position of the defect with an accuracy of 0.2mm to determine the grinding plan to ensure the rolling efficiency and the quality of the rolled steel.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic flaw detection, and relates to a detection method for internal defects of a cemented carbide roll. Background technique [0002] Due to its high hardness, high strength, heat resistance, and corrosion resistance, the tonnage of cemented carbide rolls is 10 to 20 times that of cast iron, and conventional ductile iron roll materials will not be able to withstand greater rolling force And transmit greater torque, so cemented carbide rolls are widely used in steel rolling instead of cast iron rolls. [0003] With the increasingly fierce competition in the quality and price markets of steel products, iron and steel companies are constantly updating their own equipment and technology to continuously increase the rolling speed of the rolling mill; at the same time, reducing the number of shutdowns of the rolling mill and further improving the effective operation rate of the rolling mill. This has hig...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N29/04
CPCG01N29/043
Inventor 卢少武周新华范明
Owner ZHUZHOU HARD ALLOY GRP CO LTD
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