On investigation of distribution the residual magnetization field of flat ferromagnets in the Institute of Applied Physics of National Academy of Sciences of Belarus the method and the devices type IMPOK for testing of mechanical properties of steel rolled goods moving in the production line at speed up to 25 meters per second are designed. This method is based on contactless local pulse magnetization of moving sheet from its both sides, on subsequent measurement from both sides too of maximum gradient of intensity of residual magnetic field and on their averaging. The processes of magnetization and measurement are separated in time and space. That allows more than by an order to decrease the error because the sheet displacement at moving.
The testing of method in conditions of Production (in the line of hot zinc galvanizing) (EKO Stahl, Eisenhuttenstadt, Germany) were carried out using the installation IMPOK-IB. IMPOK-1B is designed for automatic nondestructive on-line testing of mechanical properties of low-carbon steels of thickness from 0, 15 mm up to 12 mm at speed of moving in production line from 0,5 up to 5 meters per second.
For low carbon cold rolled steels the installation ensures testing ofhardness from 30 up to 100 units on a dial HRB30/100; a yield strength 
T from 20 up to 75 kgf/mm2. ultimate strength B from 20 up to 85 kgf/mm2 ; relative elongation 
10 from 2 up to 50, and also testing of depth of indentation on Erixen, average size of ferrite grain, number of a grain of ferrite.
The testing as continuous moving band , as separately following one after another sheets is possible. The installation provides the control of technological process. The soft steels (St02Z, St03Z, St05Z) and structural steels (StE250Z, StE280Z, StE320Z, StE350ZO) were tested.
On comparison of test results with results of direct destroying methods the regression models were constructed realizing the methods of current reflecting of strength properties of rolled goods along the whole coil on the display.
The visual estimation of strength properties and their comparison with given standards for tested steel are for the personnel the criteria for determination the agreement of strength properties with given technological parameters and the guarantee of receiving the suitable for that steel mechanical properties.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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