System and Experiment on Fast Testing Vermicular Graphite Percent in Cast Iron Based on Ultrasonic Longitudinal Wave

Shi, Daming; Kang, Kaijiao; Gao, Guanjun; Miao, Shen

doi:10.2320/matertrans.m2015439

Cited by 7 publications

(3 citation statements)

References 13 publications

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“…Material of the micro cracks under different loading showed different growth trends, eventually lead to fracture. Ultrasonic testing has been applied in non-destructive testing of revolved workpieces [3][4][5][6][7][8][9]. Among these, the frame scan attached to the rotary shaft is the main form of detection and the parts that need to be tested are usually solid axes or pipe fittings with little change in diameter [10].…”

Section: Introductionmentioning

confidence: 99%

Robot-Assisted Ultrasonic Testing Technology for Complex Revolved Workpiece

Wang,

Zhang,

et al. 2024

J. Phys.: Conf. Ser.

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High temperature, fatigue, and impact are the main causes of internal cracks in revolved workpieces. Crack propagation assessment is an effective method to avoid fracture. Ultrasonic testing has been widely used when testing internal cracks in revolved workpieces. However, the existing ultrasonic detection equipment makes it difficult to detect revolved workpieces with complex structures. This paper proposes an automation system including six degrees of freedom (DOF) robot, ultrasonic transducer, and turntable. The system can realize non-destructive testing automatically for complex revolved workpieces. A new method is designed to measure and correct verticality error and eccentricity error. The method was applied to detect complex revolved workpieces and the detecting resolution can be effectively improved.

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Section: Introductionmentioning

confidence: 99%

Robot-Assisted Ultrasonic Testing Technology for Complex Revolved Workpiece

Wang,

Zhang,

et al. 2024

J. Phys.: Conf. Ser.

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“…Vermicularity is one of the most important parameters for evaluating vermicular graphite cast iron. Generally, the vermicularity must be higher than 80% [7]. However, because the residual magnesium content of qualified vermicular graphite cast iron is only 0.01-0.018%, the narrow range makes the production process relatively complex [8].…”

Section: Introductionmentioning

confidence: 99%

Influence of FeS2 and FeSi75 in Double-Chamber Sample Cup on Thermal Analysis Curve and Graphite Morphology of Molten Iron

An-li

Tian

Shi

et al. 2023

Metals

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In the production of vermicular graphite cast iron, the allowable range of residual magnesium content in molten iron after treatment is very narrow, amounting to only 0.008%. Therefore, thermal analysis technology was used to quickly evaluate the vermiculation and inoculation level of molten iron at the furnace itself, thus allowing the molten iron to be adjusted in time. The additives in the sample cups play a crucial role in obtaining cooling curves with remarkable characteristics. In this study, either FeS2 or FeSi75 additives were added to one chamber of a double-chamber sample cup made of resin sand, in which the cavities of the double chambers were spherical with diameters of 30 mm. The thermal analysis curves of molten iron in the double-chamber sample cup were acquired using a double channel temperature recorder, and the solidified spherical samples were analyzed quantitatively. The influence of FeS2 or FeSi75 additives on both the cooling curves of molten iron and the graphite morphology were investigated. The experiment’s results indicated that when 0.05% FeS2 is added to one chamber of the sample cup, the cooling curve changes to the solidification pattern of gray cast iron. The continuous increase in the FeS2 additive has little influence on the shape of cooling curves, and the graphite changes form from vermicular to flaked. When the amount of FeS2 is increased from 0.05% to 0.10%, the resulting graphite changes from D-type and E-type to A-type and B-type. When the amount of FeS2 reaches 0.20%, the morphology of graphite is short and thick. With the increase in the amount of FeSi75 additive, the amount of spherical graphite in the sample cup increases gradually, and the vermicularity decreases gradually from 89% to 46%. With the increase in FeSi75 additive from 0 to 0.45%, we observed that the average diameter of graphite decreases from 23 μm to 19 μm and then increases to 22 μm. The eutectic recalescence temperature shows a decreasing trend, and the cooling curve gradually changes from a hypoeutectic to a eutectic pattern. The addition of 0.05% FeS2 or 0.45% FeSi75 to one chamber is more appropriate for a double-chamber sample cup with two spherical cavities with diameters of 30 mm. This lays a foundation for the optimization of additives when using the double-chamber sample cup for thermal analysis of vermicular graphite cast iron.

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“…For example, the ultrasonic characteristics of cast irons with different nodularities and matrix structures were reported by Collins et al [5]. Similarly, it was found that UT could be used to characterize the percent of vermicular graphite [6]. Besides, ultrasound is commonly used for defect detection, affording good sensitivity and penetration.…”

Section: Introductionmentioning

confidence: 99%

Crack Assessment of Wheel Hubs via an Ultrasonic Transducer and Industrial Robot

Zhang

Xiao

2018

Sensors

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Crack assessment when making fitness-for-service decisions requires a thorough examination of crack location and size in critical areas. An ultrasonic transducer is used for such assessments, but traditional methods cannot cope with complex rotators, such as wheel hubs. We present a model of robot-assisted crack growth assessment in wheel hubs. We integrate a six-degrees-of-freedom (DOF) industrial robot and a turntable to form a robot-assisted ultrasonic testing (UT) system that does not use traditional UT equipment. Ultrasonic beams are focused at certain depths appropriate for achieving maximum sensitivity. We quantitatively analysed wheel hubs with longitudinal and transverse series of pre-cracks, and concluded that our system autonomously detected cracks.

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System and Experiment on Fast Testing Vermicular Graphite Percent in Cast Iron Based on Ultrasonic Longitudinal Wave

Cited by 7 publications

References 13 publications

Robot-Assisted Ultrasonic Testing Technology for Complex Revolved Workpiece

Robot-Assisted Ultrasonic Testing Technology for Complex Revolved Workpiece

Influence of FeS2 and FeSi75 in Double-Chamber Sample Cup on Thermal Analysis Curve and Graphite Morphology of Molten Iron

Crack Assessment of Wheel Hubs via an Ultrasonic Transducer and Industrial Robot

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