【作者】 田建龙；

【导师】 祁欣；

【作者基本信息】 北京化工大学 ， 检测技术与自动化装置， 2003， 硕士

【摘要】 随着现代工业和科学技术的发展,无损检测技术已成为确保产品质量以及设备安全运行的重要手段,并且已经形成一门新兴的独立的综合性应用科学技术。无损检测是在不破坏被检材料或构件的情况下采用物理、化学等方法和手段,探测被检对象内部和表面的各种缺陷及某些物理性能。现代无损检测与评价技术,如超声波、X射线、磁粉、渗透和涡流技术对缺陷的定量测量,如缺陷的形状、大小、位置、取向、分布和内含物等以及对有缺陷的材料和产品的质量评价技术已具有相当的实力。但对测量铁磁性材料和产品的某些物理、力学性能,如内部应力、疲劳、组织结构、硬度、涂层厚度等,是现代无损检测更高层次的发展。巴氏噪声技术是近20年发展的、较新颖、尚需完善的无损检测技术。它可实施在线、瞬态、便携、定点、监控检测铁磁材料内部应力、疲劳寿命、硬度、显微组织、表面状态,也可对产品或设备进行整体的分析、评价。是非常有发展潜力的动态无损检测技术。铁磁材料具有较好的弹性和塑性,并且具有坚硬、耐腐、实用以及使用周期长等优点,是目前乃至今后广泛使用且不可替代的工业材料。在工业生产中,由铁磁材料加工的零部件及构成的产品,在使用<WP=4>过程中出现质量问题,破损问题及寿命终结,不仅关系到产品的正常运行,甚至关系到人身安全。因此,对铁磁材料的各种性质,如应力、硬度、疲劳等的检测具有重要的意义。本文对巴氏噪声信号的产生机理及其与铁磁材料的各种性质,如应力、硬度、显微组织状态以及疲劳程度等的关系进行了深入细致的研究。基本上掌握了在不同磁场强度下,巴氏噪声信号随各种铁磁材料的应力、硬度的变化关系。并在此基础上研制了对铁磁材料的应力和硬度进行检测的巴氏噪声应力硬度检测仪。该检测仪包括传感器、信号调理电路以及单片机三个部分。文中对这三个部分的电路结构、制作方法以及软件编程进行了详细的介绍,并给除了全部汇编语言的源程序代码。更多还原

【Abstract】 With the development of modern industry, science and technology, the Nondestructive detection technology (NDT) has become an important means to ensure the quality of products as well as the safety of the equipments and has formed a new, independent and comprehensively applied sciense and technology. The NDT technology tests the various defects and some physical properties of the material by way of physical or/and chemical means without destroying the material being tested. Generally speaking, the quantitative analysis of the defects of the material, such as the shape, the size, the location, the orientation, the distribution of the defects and the inclusions, and the estimation of the quality of the material and products that may have defects by means of modern NDT technology, such as ultrasonic, X-ray, magnetic powder, osmosis, vortex, etc, have been quite successful. But the test of some physical or mechanical <WP=6>properties, such as residual stress, fatigue, microstructure, hardness, thickness of the coating, etc, of ferromagnetic materials and products is still a little demanding for modern NDT technology.Magnetic Barkhausen Noise (MBN) technology has been developed in the past twenty years also. It is a new and still developing NDT technology and the MBN test can be carried out simultaneously, online and at appointed location. The instrument is portable and very convenient. Many properties of the ferromagnetic material, such as residual stress, fatigue life, hardness, microstructure, surface state, etc, can be tested and monitered by MBN technology and it can also be used to analysis and evaluate the state of a whole product or equipment. It is a very promising NDT technology.Ferromagnetic material has very good elasticity and plasticity and many other good qualities, such as unyielding and enduring, etc. It is a widely used industry material now and in the future and can’t be replaced. But breakdown of the products made from ferromagnetic materials sometimes may occur which can cause serious problems and may endanger people’s life sometimes. Therefore, the test of various properties of ferromagnetic materials, such as stress, hardess and fatigue, etc, is very important. In this paper, the mechanism of the generation of MBN signal and its relation to the various properties of ferromagnetic materials, such as stress, hardness, microstructure and fatigue, etc, are discussed thorougthly and <WP=7>carefully. The relationships between MBN and the stress and hardness of various ferromagnetic materials under different magnetic-field intensity have been mastered on the whole and on the foundation of which an instrument for testing the stresses and hardness of ferromagnetic materials using MBN technology has been developed. This instrument consists of three parts: the sensor, the signal alignment circuit and the singalchip. The details of the circuit structure of the three parts are introduced in this paper and the whole source program code of the assembly language is given out. Because of the limitation of my capability, there must be some shortcomings and errors in this paper, which I’d like you to point out and not to hesitate to tell me so that they can be corrected.更多还原