共查询到19条相似文献,搜索用时 140 毫秒
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正公开了一种螺旋焊缝钢管管体缺陷的横波探测方法及其探伤装置,属于超声波无损探伤领域。该探测方法通过在两螺旋焊缝之间布设垂直于焊缝的横波探头,来检测钢管表面及焊缝的缺陷,保证了检测面积达到了100%。探伤装置包括可自由升降的探头架和基本检测单元,探头架内部固设有横杆,横杆上套接有一对基本检测单元;基本检测单元由横向调节装置、探头升降装置、固定座及探头组成,横向调节装置一端与横杆套接,横向调节装置的另一端与探头升降装置连接,探头升降 相似文献
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用接收反射讯号的脉冲式超声波探伤仪(固体直探头或斜探头)检验缺陷时,正确判断任何制品的探测结果具有很重要的意义。对于普通脉冲探伤仪测量结果以波峰形式呈现在电子示波管的萤光屏上,这些波峰是由超声波能量反射脉冲和底脉冲产生的。很多因素,如缺陷的大小和缺陷的存在深度,被检验制品的表面加工质量和形状,材料的结构,超声波的频率,探头的性能等,对波峰的振幅都有影响。 相似文献
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详细描述了角焊缝的超声波检测技术,包括所用仪器、探头的选择、探测面的选定及实际探测方法,同时也介绍了缺陷数据的修正. 相似文献
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详细介绍L-S探头的设计原理,给出有关的试验数据及其在钢轨焊缝平面状缺陷探测中的应用情况等。 相似文献
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为减小或消除三维线性测头的阿贝误差,同时降低导轨运动误差对测量机测量不确定度的影响,研制一种尽可能在三维方向上同时符合阿贝原则的线性测头。该测头做三维运动,水平导轨和竖直导轨采用共平面结构;测头三维测量系统的测量线正交于一点且正交点与测头中心点重合,水平方向和竖直方向测量系统的测量线与水平导轨和竖直导轨面共面。针对此测头的特点,在参考常规测头误差分析的基础上,详细分析该测头中各项误差的影响,给出影响测头不确定度的主要误差源,对这些误差提出了修正方法。 相似文献
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Alternating current field measurement (ACFM) sensors can be used to detect surface breaking defects in metal components. In rails rolling contact fatigue (RCF) cracks form due to the wheel–rail contact stresses. These cracks are surface breaking and can have complex shapes. A COMSOL model has been developed for a commercial ACFM system and RCF cracks in rails. In this paper model results are compared to experimental measurements using an ACFM pencil probe for calibration defects machined into a rail and real RCF defects (light and moderate categories; <20 mm surface length) in a rail removed from service. X-ray tomography has been used to determine the size and morphology of the real RCF cracks for input into the model. It has been shown that the model can be used to determine the change in normalised Bx signal due to the presence of calibration defects machined into a new rail. The model has also been used to compare the experimental data for the real RCF cracks to the reconstructed model cracks and a semi-elliptical approximation to their shape. 相似文献
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C.J. Liu M.F. Jiang Y.S. Wang J.J. Chen C.L. Li 《金属学报(英文版)》2005,18(6):701-706
The mechanisms of La in heavy rail steel were studied by means of experimental measurements, microstructure observation and theoretical analysis in the present work. For heavy rail steel, the state and the content of La were measured, and the mechanisms and the effects of La on sulfide inclusions, microstracture and properties of steel were determined. Strip-like sulfides disappear in heavy rail steel with La/(O+S)〉3.50, which is shown that the metallurgical function of modifying sulfide inclusions has been achieved by La. La can fine the grain size of the austenite in heavy rail steel. Under the experimental condition, the plasticity and the impacting toughness of heavy rail steel with 0.005wt% La can evidently be improved. 相似文献
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用超声表面波来检测钢轨踏面裂纹,设计和加工了具有不同深度的裂纹试样。采用频率为0.5MHz的表面波探头对裂纹试样进行B扫描成像检测。为克服钢轨中传播的多模式表面波导致检测图像分辨率低的缺点,采用对A扫描信号移位叠加的方法对图像进行了处理。此方法不仅能对表面裂纹进行较精确的定位,也能定性区分表面裂纹的深度。 相似文献
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DONG Renze China Academy of Railway Sciences Beijing China Associate Professor Dept.of Science Technology Development China Academy of Railway Sciences Beiiing China 《金属学报(英文版)》1990,3(4):287-292
The thermal cracking and wear mechanism of rail wheel tread have been studied.The resultsshowed that the thermal cracking of rail wheel tread is related to the chemical composition(mainly the carbon content)and the hardness of the wheels.When the composite brakingshoes are used,the rate of wear of the wheel tread is related to the fracture toughness of thenewly-formed“white layer”i.e.the martensite.The thermal cracking proof wheels(55SiMn)so far developed has achieved significant operating results in practical use. 相似文献
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介绍了鞍钢中型厂结合本厂实际,采用整根冷却、整根矫直、冷锯切、轻轨自动冲孔、自动落垛、打捆的新工艺,进行精整工序技术改造及改造后取得的显著效果。 相似文献