Selection of Ultrasonic Flaw Detection Method for Type 1 Fillet Weld of Steel Slab Beam Liu Shaoyin, Yao Fuzhong. Hu Xuexiang Guizhou Boiler and Pressure Vessel Inspection Institute, Guiyang modern steel structure factory building, there are a large number of column beams and crane beams, such as the production and installation of large-scale beams. According to 1 bucket sample technical conditions and specification requirements. Human board beam wing board and board agricultural use, lamp connector. The fillet weld is required to be thorough, and the fillet weld to be welded to the nylon. According to the technical conditions and specification requirements, it is necessary to enter the hall for inspection. The earlier technical specifications seek to use the pin method to check the slab angle of the large slab beam. In order to ensure that there is no under-penetration defect in the fillet weld, the new steel structure acceptance standard; 8502051995 steel structure 1 pass construction and acceptance specification> clearly requires the ultrasonic inspection method to detect the entire section of the fillet weld, implement the national standard 083451989, steel The 8-level inspection level of the manual ultrasonic wave detection method and the classification of the detection results of the weld seam meets the requirements of the level assessment level. For the ultrasonic testing of these fillet welds, various textbooks and standards describe different flaw detection methods, some of which require straight probes to be used for detection on the wing, and some require oblique probes to be used for detection on the inside and outside of the wing , Or use an oblique probe to detect on the web. In the actual flaw detection process of fillet welds, the author compares various flaw detection methods and summarizes a better D-type fillet weld detection method for reference. 1 The production and installation of steel structure parts for the purpose of fillet weld inspection in steel structures is lagging behind that subject to a safety supervision law and standard specifications. Under the earlier technical conditions, there must be no under-penetration defects in the type 1 and 1 welds that are required to be penetrated vertically by large-slab beam members. No provisions are made for how many levels should be reached and how to detect. In recent years, due to the implementation of the engineering supervision system, more and more attention has been paid to the non-destructive testing of the welds of steel structural parts. Not only is it required to perform ultrasonic testing on the imperfections of fillet welds, but also the defects of the entire welding blood cut The inspection is carried out, and the purpose of the requirement to achieve the design quality of grade welds is to reduce the value of the safety factor by raising the requirements for the quality of steel structural parts. To achieve the lightweight of steel structural parts, while saving materials. For this reason, non-destructive testing is getting more and more widely used in the production and installation of steel structural parts, and fillet weld inspection is the top priority of steel structural testing. The choice of 2 fillet weld detection schemes is that the material of ordinary I-shaped girder is generally 3 or 16, 1 steel, and the thickness of the wing is greater than the thickness of the web, generally 122, and the web is generally 6141. The total degree of the girder The welding of type 1 fillet welds ranging from 720 is automatic submerged arc welding, and sometimes manual arc is also used. The height of the weld fillet is based on the counterweight work system and 5, 1 2.1 The ultrasonic inspection scheme of fillet welds is selected with the probe in the wing On-board fillet weld inspection 1. This method first considers the near-field area of ​​the straight probe. If a straight probe with a diameter of 1, such as 2.5 mm is used, the near field of the straight probe is calculated to be 2, so for a thickness of 122 , The wing is obviously unable to detect. In recent years, some small diameter direct protection head or product probes have a short near field area, which can detect type 1 fillet welds on the wing, but can only detect defects in the middle of the fillet weld, and cause reflected waves on both sides of the web The clutter makes it difficult to judge defects. In addition, when flaw detection is not seen on the wing, it is necessary to draw a line on the wing or use the edge of the wing as a reference to correct the position of the straight probe to judge the position of the defect. Therefore, flaw detection with a straight probe is troublesome and has certain difficulties. Use the oblique probe to detect the outside of the wing 2. This detection method also has no fillet welds on the wing plate, so it is necessary to draw a line on the wing plate or rely on the edge of the wing plate as a reference to determine the position of the inclined probe. However, this benchmark is inaccurate, because during the welding of the slab beam, the entire slab beam will be twisted and the wing plate will be deformed by 5 curves. Although these distortions and deformation scenes can be corrected in the calibration process and controlled within a certain range, according to the requirements of the manufacturing process, the ultrasonic flaw detection is before the calibration process, because the ultrasonic flaw detection may cause welding rework to cause welding distortion. Therefore, determining the position of the oblique probe by drawing a line or the edge of the wing to determine the position of the defect is also accurate, which is easy to misjudge the reflected wave. In addition, it is necessary to understand the position of the probe and determine the position of the reflected wave during the flaw detection process, so this method takes time and 1 to perform ultrasonic flaw detection on the inside of the wing, because the position of the defect of the fillet weld on the back of the web cannot be determined. It is generally not accepted. Ultrasonic testing on the web is a good method of flaw detection. This method is similar to the flat butt weld inspection method. The web remains intact after welding. The distortion of the slab beam and the deformation of the wing plate will not affect the positioning of the ultrasonic detection. The fillet welding basket can be observed during the flaw detection. The slab beam is placed flat on the ground after welding, which provides a good inspection station for ultrasonic flaw detection. When you use the earlier technical conditions to detect flaws, if you use the special 2 oblique probe, as long as the defect wave appears in the vicinity of the position of the horizontal plate thickness in the horizontal direction, you can confirm the existence of unwelded defects, and determine the defect is simple and clear. The level 8 inspection requirements of 7.2.2 apply. That is, in principle, a variety of angle probes are used to inspect the single and double sides of the weld, and the detection of the entire weld cross section is limited by geometric conditions. Two angle probes can be used to detect flaws on both sides of the weld. The flaw detection of beam-type stone welds is restricted by any conditions. When testing on the strand board, a double-sided single-sided probe with two angles should be used for inspection to ensure that the entire welding section can be scanned, including fillet welding on both sides. Seam welding meat. 2.2 Selection of detection conditions 1 The choice of probe is based on the thickness of the web. Select the probe of You 2 or You 2.5, because the welding angles of the two sides of the fillet weld form an isosceles right-angled shape, when using the 2 or 2.5 probes for flaw detection, there is a scanning blind area on both sides of the weld, the larger the value of the probe. , The scanning blind area will be larger, so in order to ensure that the ultrasonic scan to the entire weld cross-section, you must choose another person 1 inclined probe, so as to ensure that the entire weld cross-section is scanned, and meet the two requirements of the inspection level 6 Requirements for flaw detection at different angles 3. The adjustment of the baseline ratio at 3 o'clock is similar to the thickness of the web at 2, so the adjustment of the time baseline is a horizontal ratio. Medium; 3 test blocks, sensitive projection 161 coupling compensation is used to detect scanning and flaw detection, the oblique probe performs a zigzag scan perpendicular to the fillet weld on the side of the weld web, the distance between each movement is not greater than the wafer diameter, and Make 1015 rotation during the movement. In order to detect the transverse defects of the weld. The probe should also be scanned along the center line of the weld seam in the forward and reverse directions. Welcome to subscribe to Pressure Vessel Magazine. Pressure Vessel Magazine is a central-level publication. It has been changed to a monthly publication from 12002 by the Department of Public Development at home and abroad. The 64 edition is priced at 8.00 yuan per period and 96.00 yuan for the whole year. The post office subscribes to the code 2610. The China International Book Trading Corporation Beijing 399 is issued abroad, and the code is 15298 River. 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And the technological progress of internal and external pressure vessel research and development, pressure industry, industry development, Zhanxi Temple, missed the post office subscription, please contact the editorial department directly to make a reservation or visit the address, 8881 Changjiang Road, Hefei City, Anhui Province. Recruitment of the 17th World NDT Conference Co-organizer International NDT Committee 1 decision, the 17th World NDT Conference hosted by the International NDT Committee 17 out of the Chinese Society of Mechanical Engineering Special Damage Testing Branch The NDT Conference was held in Shanghai, China in 2008. Tester meeting. Promote the development of non-destructive testing in various countries, and enhance the friendship between non-destructive testing counterparts in various countries. It is discussed by the chairman and deputy chairman of the non-destructive testing branch. Recruitment is now No. 17; the main obligation of the co-organizers of the NDT conference co-organizers is. Assist the NDT branch to host the 17th World NDT Conference and Exhibition, and prepare to organize the 17th World NDT Conference in 2008, including the solicitation of papers for solicitation and reception, and reception of domestic and foreign conferences. Jointly assume responsibilities and obligations and share the results of the meeting. Recruitment will be discussed and approved at the executive meeting of the Society in February and March of 2002. The office was originally located in Shanghai and Shanghai, and the non-destructive testing branch secretariat 3 ultrasonic characteristics of D-type fillet welds. In the process of steel structure fillet weld detection, the main defect in the weld is not fully penetrated. Make the defect perpendicular to the ultrasonic beam as much as possible, so try to choose a probe with a larger value. In the two angle probe flaw detection, the focus is on the flaw detection of the probe 2 or 2.5, because it can detect most defects in the weld, including the main defects. When judging the internal defects of the wing plate, the dual crystal straight probe or oblique probe should be used to scan the inside and outside of the wing plate to confirm whether there is a lamellar tear. Especially for the history of large plate beams made of alloy steel materials, this inspection should be selected. More advanced ultrasonic flaw detection is used so that the distance amplitude curves of different ultrasonic probes used for flaw detection are stored in the instrument. flaw detection. 4 Conclusion In the process of making and installing steel structure parts. Choosing a good ultrasonic flaw detection method for D-type fillet mortar is a very important factor to ensure the quality of the inspection. In general, the ultrasonic inspection personnel mainly focus on butt welds during the inspection process, and the flaw detection of the diagonal welds Not very familiar, so in the actual flaw detection process of fillet welds, flaw detection personnel should continue to explore, accumulate experience, verify the flaw detection results, ensure the flaw detection results are correct and reliable, in order to achieve the purpose of fillet weld detection Here you can find the related products in Lexmark, Canon and more brand printer parts, If you want to know more about Lexmark, Canon printer parts, please click the product details to view models, pictures, prices and other information. Whatever you are a group or individual, we will do our best to provide you with accurate and comprehensive message about Lexmark, Canon printer parts! Printer Parts,More Printer Parts,Hp Printer Parts,Part Print Dunhua Office Equipment Co., Ltd. , https://www.dunhuaparts.com
Selection of ultrasonic flaw detection method for T-shaped fillet welds of large steel plate beams