共查询到18条相似文献,搜索用时 203 毫秒
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对超声波C扫描检测系统的发展历史和发展方向作了简要的叙述和归纳,对国内外的超声波C扫描检测系统产品进行了简单介绍,对超声波C扫描检测中常见的平面扫查系统、回转体扫查系统、大型空间曲面构件扫查系统、管材与棒材旋转行进的扫查系统和便携式扫查系统等五类系统的特点和应用范围进行了总结,为业界选择合适的检测系统提供帮助。 相似文献
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为了避免钢管在线自动超声波探伤过程中管端检测盲区切除的资源浪费以及补充管端人工探伤引起的成本增加,设计研制了一套管端自动超声波探伤系统。此探伤系统采用托辊装置带动钢管原地旋转、探头组沿钢管轴向移动的扫查方法,通过PLC控制带动钢管原地旋转的变频器和带动探头组前后移动的伺服电机实现对钢管管端的无盲区探伤检测,在确保钢管质量的同时提高了生产效率。 相似文献
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(上接 2 0 0 2年第 1期 )3 检测运筹环节 3—检测的空间覆盖性3.1 超声波的通透性3.1 .1 超声波在被检物表面的通透性保证超声波从探头中进入工件 ,这是实施超声波检测的首要条件。为此我们使用了耦合剂 ,并对探头所接触的工件表面进行处理。各检测标准均规定了探头移动区 (或称检测面 )清理的最低要求 ,即是 :1探头移动区应清除焊接飞溅、铁屑及其它外部杂质。2探伤表面应平整光滑 ,便于探头的自由扫查。3其表面粗糙度不应超过 6.3μm,必要时应进行打磨。在实施超声波检测前 ,检测人员都要进行现场察看 ,对被检物表面清理程度是否适于检… 相似文献
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介绍了厚壁承压无缝钢管超声波探伤方法,自动化探伤中探头的扫查设计,以及采用该方法开发的钢管自动探伤设备的实用效果。 相似文献
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介绍了用于火车轮箍在线超声波检测的多晶片水浸聚焦探头结构,性能参数 声束在工作检测宽度方向的连续覆盖,并以100mm/s线速度扫查时,可一次完成对工件全扫查,提高工作效率且满足检测工艺要求 相似文献
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小波神经网络的数据压缩技术在超声自动探伤系统中的应用 总被引:1,自引:0,他引:1
为了实现对大型回转体零件内部缺陷的检测与识别,研制了超声波自动检测系统.系统主要完成超声信号的采集和处理、数据的实时存储、缺陷的在线分析与识别等功能.要实现缺陷的在线检测与识别,必然需要大量的原始数据,为了减少数据的存储量,通过小波神经网络提取相应的权重因子,构成小波基的尺度参数和与之对应的平移参数,实现缺陷有用信息的压缩;在缺陷数据重构中,利用上述特性参数并结合信号的特征值,对信号进行拟合.解决了缺陷检测现场大量数据的保存问题,为缺陷的进一步识别提供了基础. 相似文献
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残余应力的存在在一定程度上影响了工件的疲劳寿命和抗腐蚀能力等,调控工件内部残余应力的分布在工程应用上具有很高的研究价值,合理调控应力能够有效抵抗工件表面的裂纹萌生,提高工件表面整体完整性。具体阐述了残余应力的概念和分类;分别从铣削、磨削和焊接角度归纳了传统加工过程中残余应力的产生机理及其对材料性能的影响;对相关残余应力检测技术的原理和优缺点进行论述;概述了残余应力有限元计算方法;综述了各种加工方法下,工艺参数对工件表面残余应力产生的影响;针对优化工艺参数调控残余应力无法满足工件的整体性能需求,归纳了时效法调控残余应力的机理;综述了能够进行应力调控的表面强化处理技术,包括机械作用下的孔挤压强化、超声振动磨削、喷丸工艺、超声滚压和激光冲击、能量外部输入下的高能声束调控技术、高能量密度脉冲电流和激光辐照应力调控技术。此外,针对单一表面强化处理技术调控残余应力的不足,概述了超声挤压-激光冲压、激光冲击-超声滚压以及激光冲击-喷丸等相关的复合表面强化工艺。最后,指出了表面强化处理技术处理复杂曲面,以及复合表面强化工艺是未来表面完整性加工的发展方向。 相似文献
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This paper proposes an alternative centerless grinding technique, i.e., through-feed centerless grinding using a surface grinder. In the new method, a compact centerless grinding unit, composed of a guide plate, an ultrasonic shoe, a blade, and their respective holders, is installed onto the worktable of a surface grinder, and the through-feed centerless grinding operation is performed as the workpiece located on the guide plate is fed into the space between the grinding wheel and ultrasonic shoe. The ultrasonic shoe, produced by bonding a piezoelectric ceramic device onto a metal elastic body, is tilted at a small angle so as to provide sufficient force to control the workpiece rotational motion and to feed the workpiece along its axis by the ultrasonic elliptic-vibration. In this paper, the workpiece motion control tests were carried out firstly to make sure that the workpiece rotational speed and through-feed rate can be exactly controlled by the ultrasonic shoe which is essential for performing high-precision grinding operations. Then, the effects of major process parameters such as the workpiece eccentric angle, the stock removal, the ultrasonic shoe tilt angle and the applied voltage amplitude on the machining accuracy (i.e. workpiece cylindricity and workpiece roundness) were clarified experimentally. The obtained results indicate that: (1) the workpiece rotational speed can be adjusted by changing the applied voltage amplitude, whereas its through-feed rate can be adjusted by changing both the applied voltage amplitude and the ultrasonic shoe tilt angle; (2) the optimum eccentric angle is 6°, and a larger stock removal, a smaller tilt angle, or a higher applied voltage is better for higher machining accuracy; (3) the workpiece cylindricity and roundness were improved from the initial value of 16.63 μm and 14.86 μm to the final ones of 1.49 μm and 0.74 μm under the optimal grinding conditions. 相似文献
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This paper deals with the development of an alternative centerless grinding technique, i.e., in-feed centerless grinding based on a surface grinder. In this new method, a compact centerless grinding unit, composed of an ultrasonic elliptic-vibration shoe, a blade and their respective holders, is installed onto the worktable of a surface grinder, and the in-feed centerless grinding operation is performed as a rotating grinding wheel is fed in downward to the cylindrical workpiece held on the shoe and the blade. During grinding, the rotational speed of the workpiece is controlled by the ultrasonic elliptic-vibration of the shoe that is produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body (stainless steel, SUS304). A simulation method is proposed for clarifying the workpiece rounding process and predicting the workpiece roundness in this new centerless grinding, and the effects of process parameters such as the eccentric angle, the wheel feed rate, the stock removal and the workpiece rotational speed on the workpiece roundness were investigated by simulation followed by experimental confirmation. The obtained results indicate that: (1) the optimum eccentric angle is around 6°; (2) higher machining accuracy can be obtained under a lower grinding wheel feed rate, larger stock removal and faster workpiece rotational speed; (3) the workpiece roundness was improved from an initial value of 19.90 μm to a final one of 0.90 μm after grinding under the optimal grinding conditions. 相似文献
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