Effect Of Different Loading Speeds On The Evolution Of Magnetic Field In Ferromagnetic Steels

Metal magnetic memory testing is a new method of nondestructive testing. It used the magnetic memory effect generated by ferromagnetic materials under the action of the tensile load and the earth magnetic field to detect the stress concentration zone in steels quickly. However, the microscopic mechanism of the technology is not yet clear. The relationship between the load and magnetic memory signal is very difficult to quantify, and the loading speed is an important factor affecting the relationship. This paper mainly study the data obtained by different loading speeds at different loading stages. The influence of different loading speeds on the magnetic memory signal and the evolution law of the steel under different loading stages were studied.The main content of this paper was divided into two parts. In the first part, the influence of different loading speeds on the residual magnetic field of the steel after loaded was studied. Under the same loading stage, the relationship between the residual magnetic field and the loading speed was studied by two different speeds of tensile test. Then the influence of the normal magnetic field and tangential magnetic field on the loading speed was studied, and the related curves were obtained. Secondly, by changing the load stage, the influence of the residual magnetic field of the specimen under different loading stages was further studied, and the relationship among these three parts was further studied. The second part is to research on the influence of five kinds of different loading speeds on the piezomagnetic field changes in the tension of steel By changing different loading speeds and loading stages, the extent of the impact on the piezomagnetic field of the demagnetizing steels was analyzed, and got the relationship curve. Therefore, the paper studies the relationship among the three aspects of the loading stage, the loading speeds and the magnetic memory signals from the two aspects of the residual magnetic field and the piezomagnetic field.