钢管涡流探伤可靠性分析

从原理上分析了钢管涡流探伤中采用穿过式自比差动线圈对纵向裂纹类缺陷检出率低的原因,并通过试验进行了验证。阐述了影响钢管涡流探伤可靠性的因素,提出了改善钢管涡流探伤可靠性的几点建议。     

组合无损检测技术及其在无缝钢管在线自动检验中的应用

分析了常规无损检测方法的特点及其局限性,讨论了以热轧无缝钢管为检测对象时检出各类缺陷的组合原则。在此基础上介绍一种由电磁分钢、涡流探伤、漏磁探伤及超声测量组成的钢管在线组合检测技术及其应用结果。实践证明,它能够有效地在钢管生产流水线上起到质量把关的作用     

钢管涡流检测可靠性试验研究

在试验样管上制作人工缺陷，进行涡流检测探伤，分别进行了检测频率与伤深，伤形状，伤相位，Ａ级和Ｂ级钻孔的灵敏度差，钢管同心度与检测灵敏度的关系等项检测试验，并对试验结果进行了分析总结，据此提出了钢管涡流检测可靠性的方法。     

GB/T7735—1995钢管涡流探伤检验方法国家标准修订说明

GB／T7735－1995钢管涡流探伤检验方法》等效采用国际标准ISO9304－1989（E）用于压力目的无缝钢管和焊接钢管（埋弧焊除外）涡流探伤检查｝），代替GB7735－87。在修订过程中查阅了英国标准BS3889／ZA－1986（gi）《钢管的无损检测一黑色金属管材的涡流检测法》、美国标准ASTME309－1983（95）《钢管涡流检验方法（磁饱和法）》、日本标准JISG0583—1978钢管的涡流检验方法》等。结合1988年以来国内钢管涡流探伤技术的情况，使修订后的标准既保持与ISO9304一1989（E）等效．又适合我国具体情况。1关于涡流探伤的范围国际标准的…     

连铸热坯双频涡流探伤技术

采用二维涡流探伤模型,研究了涡流传感器的结构参数对探伤灵敏度的影响,并将双频涡流探伤技术用于坯料表面缺陷检测,结果表明,缺陷深度增加所引起的探头阻抗变化使其相角发生变化。     

涡流探伤干扰信号的抑制技术

本文针对钢管涡流探伤过程中出现的噪声干扰引起误报的现象,在现场实验及分析涡流探伤信号处理方法的基础上,提出了开启涡流噪声抑制扇区、减少设备误报的解决方案,并给出了具体的设置方法.     

钢管的涡流探伤

钢管的涡流探伤粤海钢管厂曾祥照一、钢管无损检测的必要性钢管是国民经济各领域常用钢材，主要用来输送各种承压流体或制作各种结构件，对其自身质量有着较高的要求。如果无缝钢管中存在裂纹、夹层、折迭、重皮等缺陷，就有可能发生爆管、泄漏等事故；如果有缝钢管存在着...     

自动探伤设备检测缺陷能力的评价试验

采用若干符合用户要求的带有两种人工缺陷的样管,在钢管公司的漏磁探伤和超声波探伤机组进行了自动探伤设备检测缺陷能力的评价试验。结果表明,各探伤机组全部能够稳定地检测出钢管存在的横、纵向缺陷。漏磁探伤对斜向缺陷的检出效果优于超声波探伤。公司主要自动探伤设备能力能够满足大型石油公司的要求。     

钢轨自动涡流探伤装置的开发

1 前言钢轨质量对确保交通运输机械及运输设备的安全是非常重要的。从这一认识出发,日本钢管公司福山厂在确立万无一失的质量检查体制的同时,积极地采取了各种有力措施,如开发并采用了检查内部质量缺陷用的超声波探伤装置(译文见《无损检测》Vol.10,№.7,1988,225～227——译者注)、弯曲计等自动检查装置。此次,成功地开发了检查表面缺陷用的涡流探伤     

钨丝探伤缺陷及影响因素研究

介绍了照明行业对钨丝的基本要求.采用涡流探伤对D0.39 mm钨丝进行了探伤检测,通过对探伤缺陷部位的取样及金相观察,总结了几种典型的缺陷类型,并对其产生原因和影响因素进行了简要分析.     

宝钢轧辊涡流检测技术的应用和发展

针对宝钢从国外引进的轧辊涡流探伤设备出现的问题着重介绍冷轧辊表面缺陷的涡流检测原理，应用，存在问题及解决办法。     

Psychometric detection of schizotypy.

Genetic studies of typical schizophrenia require accurate means for the detection of carriers of the heritable diathesis. Psychometric methods have been developed, often for studying psychosocial transmission of schizophrenia, that might be useful for genetic studies. Studies of schizotypy detection using the Goldstein-Scheerer Object Sorting Test, Rorschach technique, TAT, and MMPI are reviewed. Most studies suffer from serious conceptual and methodological flaws that have made replication a rarity. Recent approaches emphasizing clinical signs and symptoms that bear a close content relationship to the typical schizophrenic syndrome are asserted to be more likely to bear fruit. (1? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Minimally invasive saphenous vein harvesting: endothelial integrity and early clinical results

Eddy current effects induced by switched gradients in proximal conducting structures are traditionally reduced by applying preemphasis currents whose amplitudes and decay characteristics must be set to offset the eddy current fields. We present an expeditious, localized, and quantitative method for mapping and adjusting the parameters for eddy current compensation. Mapping is based on analysis of projections as used in the fast automatic shimming technique by mapping along projections (FASTMAP). Adjustment methods are demonstrated in high-field horizontal bore systems. The proposed localized eddy current mapping technique may also be used for localized measurements in situations where asymmetric conducting structures may cause nonlinear eddy current fields, such as in interventional MRI and open magnet designs.     

国外钢轨涡流检测技术现状

叙述了涡流检测法原理和利用涡流法检测钢轨表面缺陷的几种方法；同时介绍了国外几个钢轨生产厂研究开发的涡流检测装置。     

钢材涡流检测中的信号分析与处理

钢材涡流检测中检测线圈的输出信号十分复杂,对此信号进行准确的分析与处理,是获得高精度和高可靠性检测结果的基础,本在对涡流检测线圈输出信号进行详细分析的基础上,提出了正交双通道相干检测波的数学分析模型和相应的信号处理电路,在涡流探伤仪的设计和钢材探伤应用中满意的效果。     

Tracking of cracks in sheet steel specimens under cyclic loading

In this report a non-contact gauging system based on eddy current technology is presented which permits unproblematic detection and tracking of cracks initiated by cyclic loading in sheet steel specimens. In comparison with other measuring methods the automatic pilot unit developed displays distinct advantages thanks to its highly accurate measuring results. This measuring unit is suitable for the examination of thin sheet steels (< 2 mm) and has been successfully used for studying ductile materials. Some results of such investigations are therefore illustrated.     

Influence of Surface Condition on the Inspection of Steel Bridge Elements Using the Time-of-Flight Diffraction Method

Prior studies on the time-of-flight diffraction (TOFD) method have focused primarily on ground smooth, clean surfaces of steel. In practice, however, the surface of an existing bridge element will be covered with rust or have several layers of paint. The main objective of this study was to evaluate the influence of the surface condition of steel elements (i.e., painted or rusted) on the ability of the method to accurately detect and size flaws. These objectives were met by performing a number of tests on plates with saw cuts or implanted fatigue cracks with different surface conditions. These included ground smooth and polished, rusted, and painted surfaces. The data show that rusted surfaces will reduce the amplitude of the ultrasonic signals, but they will not impair the ability of the TOFD method to detect and accurately size flaws. A painted surface will also cause a reduction in signal amplitude. More important, however, is the appearance of additional wave signals that could be interpreted as false indications. While these additional signals do not obscure the presence of actual flaws or affect the accuracy of the TOFD method to size the flaws, they make flaw detection more difficult. Based on the results of this study, recommendations for field inspection on rusted or painted surfaces using the TOFD method are provided.     

TP2铜管精整工序喷墨质量不良原因分析及改进措施初探

在精密铜管精整复绕工序中,涡流探伤装置检测到伤点后会向喷墨装置发送信号,以对铜管表面缺陷进行喷墨标记,但是该过程普遍存在喷墨不良,严重影响了对缺陷的判断。本文介绍了TP2铜管生产线中涡流探伤仪器的工作原理,对原有的涡流探伤仪器、喷墨装置以及喷枪结构进行调研,分析了原有喷墨装置喷墨时存在的漏墨和拖墨问题,探讨了等离子技术与激光刻蚀技术作为喷墨技术替代方案的可能性。文献调研、现有技术分析及其他替代试验的结果表明,采用等离子体表面处理技术对已喷墨铜管进行处理后,可以一定程度地改善铜管拖墨的问题;采用功率为300 W的激光对铜管表面进行刻蚀处理,激光头速度分别为80 mm/s和200 mm/s时,对铜管表面刻蚀呈现出的不同效果,均能够进行缺陷的有效标识。因此,铜管表面激光刻蚀技术可以作为喷墨技术的替代方案。     

冷床液压系统故障分析排除与改进

通过对棒材冷床液压系统故障进行分析，提出了排除方法，并对存在的问题采取了改进措施。