Magnetic particle inspection magnetic particle flaw detector used by the origin and principles of law


magnetic particle testing machine using magnetic particle test method, also known as magnetic particle method is a nondestructive testing method used in many earlier. Vision of magnetic particle testing method is an American Zhai Ke (Hoke) introduced in 1922. When he was grinding workpieces made of steel, found often by grinding down of late iron artifacts (magnetic fixture clamping), form a certain pattern, patterns are always consistent with the shape of surface cracks of workpieces. So he came up with this concept of inspection of surface cracks of workpieces. Application of real success until in the early 1930 of the 20th century, Watts (Waus) using magnetic particle inspection method for steel pipe weld quality is tested. Successfully applied to magnetic particle testing has brought development opportunities, in the decades since then, magnetic particle testing has been widely studied, magnetizing method, the test method has been pioneering the development; a variety of testing equipment available, materials were developed, updated and progress detection techniques improved gradually, realize normalization and standardization.


magnetic particle inspection magnetic particle test method is applied throughout the industry. Machinery, aviation, aerospace, chemical, oil, shipbuilding, metallurgy, railway and other industries are particularly common. Manufacturing quality control can be achieved with it, to test raw materials, process artifacts are often prone to defects testing, finished product testing, early detection of defects at an early stage to weed out unqualified raw materials, parts or to repair them as soon as possible, products can bring better economic benefits.

magnetic particle testing is widely used in existing industrial facilities, maintenance of equipment seized Zha, such as boiler, pressure vessels, piping systems, and aircraft and bridges against research that they are dangerous safety defects and use to evaluate their security situation. Mainly for detection of magnetic materials or parts and components of surface and near-surface defects.


magnetic particle testing machine using magnetic particle method is the basic principle of when components of ferromagnetic material under external magnetic field become magnetized, magnetic force transmission in the component. As the surface and near-surface defects, hinders bending force field lines due to defects in extensive air leakage, leakage magnetic field in the appropriate location. Imposed on the members by observing the magnetic marks referred to as magnetic, you can determine the position, orientation and size of defects. When a ferromagnetic workpiece is magnetized, the material of the workpiece to be continuous and uniform, the magnetic induction line is constrained in the workpiece in the workpiece almost no surface of the magnetic induction line from the check out or into the workpiece, seized pole surface formation, adsorption of magnetic particles. But when the surface of the workpiece when cut magnetic lines of force of the defect exists, due to the deficient permeability is small, magnetic resistance is large, magnetic induction line will change the way. Most change the way magnetic flux will give priority from the reluctance of small defects in the bottom of the workpiece through. If the artifacts within the magnetic flux density is large, defects difficult to accept at the bottom of the workpiece more flux, or defect when the scale is large, part of the magnetic flux will escape artifacts from defective parts, across the defect and then into the workpiece at the top, on both sides of the magnetic flux leakage while the defect part of magnetic polarization, forming the so-called magnetic leakage.


magnetic particle testing method is magnetized by magnetic particle inspection machine the workpiece, is sprayed on the surface of the workpiece by magnetizing magnetic or magnetic suspension, defect leakage magnetic field and magnetic particle interaction analysis, distinguishing whether a defect exists. If artifacts surface has defects exists, magnetic powder of particles will immediately was defects leak magnetic field magnetization, makes each magnetic powder particles are became has n, and s very of small magnet), and and defects pole phase role, specific pole mutual attract, makes magnetic powder is chain-like adsorption in defects where of surface Shang, gathered into defects magnetic marks, displayed defects bit. reset, and shape and size, due to leak magnetic field of role range than actual defects of width to big number times to dozens of times times, so magnetic marks of width than actual defects width to big have more, is easy observation.


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