Series of Portable Structuroscope-Instruments Based on Measuringthe CoerciveForce

A series of instruments (structuroscopes) assigned for determining various characteristics of materials and products on the basis of the coercive force is described. Main technical characteristics of three types of the instruments are given. The last and most perfect modification is KRM-Ts-K3 instrument. It is provided with a self-contained power supply and has a wide measurement range. It has an internal memory for 4096 measurements and can be connected to a personal computer. Specially designed program software makes it possible automatically to construct graphs. Examples of graphical representation of the measurement data are demonstrated for two- and three-dimensional reproduction of the results.     

Portable Electromagnetic-Acoustic Thickness Meters (EMAT)

Two varieties of contactless electromagnetic-acoustic portable thickness meters with autonomous power supply, created on the basis of up-to-date digital technologies, are described. The instruments implement a new highly efficient design of magnetic field concentrator developed on the basis of new magnetic materials. The -- thickness meter is equipped with a powerful microprocessor-based data processing system, which expands the capabilities of the instrument. The -100 thickness meter is a small-size and small-weight instrument. The main advantage of both instruments is that they can be operated on corroded untreated surfaces without the use of a contact fluid. Both instruments are suitable for testing through coatings of considerable thickness (up to 2 mm) and can be operated under workshop and field conditions.     

Magnetic Measurements of Stressed-Strained States and Remaining Service Lives of Steel Structures in Hoisting Machines and Pressurized Vessels

A technique of magnetic diagnostics has been developed on the base of correlations between physico-mechanical properties of ferromagnetic materials and their coercive force H _c. Examples of practical utilization of the technique in assessing conditions of bridge cranes and oxygen cylinders are given. By solving the inverse problem, it is possible to diagnose the stage of transition to the yield region on the base of measurements of the maximal and average coercive force, which enables one to diagnose the predestruction condition of gas cylinders. Criteria for rejecting gas cylinders based on results of statistical analysis have been established.     

Evaluation of the Current Condition and the Residual Lifetime of Forming Rolls Using the Magnetic Method of Nondestructive Testing Based on the Coercive Force

The magnetic method on the basis of the coercive force H_c is proposed to use for estimating the current condition and the residual lifetime of forming rolls. Sixty rolls have been tested. It is shown that H_c increases almost twice in exploiting the roll from the beginning of the operation to reaching the limit of its lifetime. Results of observation of the degree of nonuniformity of the H_c distribution over the roll surface in the operation process are given. The results of investigation make it possible to optimize the path of each roll through the mill stands in order to avoid the stress concentration at the same depth of the roll operating (magnetic) coating in the roll change process. Using the magnetic testing method based on H_c makes it possible effectively to estimate the current condition of accumulation of the fatigue in the roll operating (magnetic) coating.     

Portable Contactless EMA Thickness Gauge

A portable contactless EMA thickness gauge for nondestructive testing of the thickness of a wide range of conducting products, in particular, for testing products from ferromagnetic and aluminum alloys, is developed. The results of investigations of the device are given.