Magnetic measuring device and its realization method for the martensitic phase transformation of medium manganese steel

Abstract

The invention discloses a medium manganese steel martensite phase transformation magnetic measurement device, which comprises a magnetic shielding space and a gantry-type measurement frame. The medium manganese steel martensite phase transformation magnetic measurement device also comprises a probe clamp fixedly arranged in the gantry-type measurement frame, a magnetometer probe arranged under the probe clamp, a fluxgate magnetometer digital displayer connected with the magnetometer probe and arranged outside the magnetic shielding space, a non-magnetic sliding table arranged under the magnetometer probe and used for placing medium manganese steel samples and positioning sample coordinates, a screw rod connected with the non-magnetic sliding table and used for enabling the non-magnetic sliding table to carry out reciprocating rectilinear movement, and a fixation base arranged on the gantry-type measurement frame and used for fixing the two ends of the screw rod. The DC remanent magnetism in the magnetic shielding space is 1mGs. The medium manganese steel martensite phase transformation magnetic measurement device and the realization method thereof belong to nondestructive test, not only can qualitatively judge the content of martensite in medium manganese steel and measure positive correlation relation between the magnetic field amplitude and sample impact toughness, but also is flexible in detection mode and does no harm to human body.

Description

technical field [0001] The invention relates to the detection and characterization of the martensitic phase transition of medium manganese steel, in particular to a magnetic measuring device and a realization method for the martensitic phase transition of medium manganese steel. Background technique [0002] After the austenitic medium manganese steel is impacted by medium and low loads, martensitic phase transformation will occur on the surface, the hardness will be greatly improved, and the wear resistance will be greatly enhanced. The wear resistance under medium and low loads is better than that of high manganese steel. Tensitic transformation is the key factor for its wear resistance. In the usual analysis and detection methods, the mechanical property test cannot directly determine whether martensitic transformation has occurred in the sample and the amount of martensite. Metallographic microscopic analysis can see the surface microstructure and grain size, but the amo...

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Problems solved by technology

[0002] After the austenitic medium manganese steel is impacted by medium and low loads, martensitic phase transformation will occur on the surface, the hardness will be greatly improved, and the wear resistance will be greatly enhanced. The wear resistance under medium and low loads is better than that of high manganese steel. Tensitic transformation is the key factor for its wear resistance. In the usual analysis and detection methods, the mechanical property test cannot directly determine whether martensitic transformation has occurred in the sample and the amount of martensite. Metallographic microscopic analysis can see the surface microstructure and grain size, but the amount of internal martensite cannot be judged, and in the XRD pattern of medium manganese steel, the peak difference between austenite and martensite is very small, and the amount of martensite Far less than austenite, coupled with possible errors and impurities, it is difficult to judge whether martensitic transformation has occurred only from the XRD pattern. A detection method with higher sensitivity and capable of detecting internal martensite and corresponding detection device

[0003] Another invention of the applicant, "Measurement Device and Method for Displacement of Objects in Paramagnetic Boxes Based on Magnetic Markers" (patent application number: 201610029340.6) discloses a measuring device that can realize the displacement of objects in paramagnetic metal or non-metal boxes. Non-destructive testing of the displacement, but it cannot be used for magnetic measurement of the martensitic phase transformation of medium manganese steel

The reason is that the grating ruler is installed in the device. Although the one-dimensional distribution of the magnetic field of the sample can be measured by moving the fluxgate magnetometer probe, the grating ruler itself is also magnetic, which will generate a background magnetic field of about 3mGs, and the medium manganese after impact The weakest steel magnetic field is less than 0.5mGs, so the grating ruler will seriously affect the measurement of the martensitic transformation of medium manganese steel

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