CN103389316B - silicon steel texture measurement method - Google Patents

Abstract

The invention discloses a kind of silicon steel texture measurement method, step is as follows: preparation EBSD analytical sample; With the distribution of orientations figure in half thickness of slab region of at least 3 different-thickness positions, EBSD device measuring sample longitudinal section; Measured zone is divided at least 10 homalographic regions along surface of steel plate to thickness of slab center, obtains the ODF figure in diverse location region by analysis; Calculate each { density fraction f (hkl) of hkl} crystal face; To zones of different stack pile position { the density fraction f (hkl) of hkl} crystal face averages; Obtain the data plot of Texture thickness of slab directional spreding.The present invention is by measuring ODF figure, and quantitative calculating is each, and { the density fraction f (hkl) of hkl} crystal face, compensate for the difficulty of XRD quantitative test.Meanwhile, by measuring the data in multiple region, eliminating EBSD measured zone too small and cause the impact of error, making data more accurate.<!--1-->

Description

Silicon steel texture measurement method

Technical field

The present invention relates to the measuring method of silicon steel, refer to a kind of silicon steel texture measurement method particularly.

Background technology

Orientation silicon steel is the important soft magnetic material being widely used in electric power, electronics industry.If the preferred orientation of obtaining, the arrangement of individual crystal grain makes its <001> axle almost roll with steel plate to parallel, the iron loss of orientation silicon steel can be reduced, improve magnetoconductivity, increase the magnetic circuit of direction of easy axis, make material be more suitable for the applications such as generating and substation transformer, therefore improving texture is the effective way reducing iron loss and improve magnetoconductivity.

Research silicon steel is the key controlling silicon steel production technology in the texture of the steel plate of the different operations such as hot rolling, normalizing, decarburizing annealing, the final performance determining silicon steel.The most outstanding feature of orientation silicon steel is from hot rolling technology, just there is texture difference (title texture gradient) from sample surfaces to center.Therefore, the distribution situation in Texture thickness of slab direction is an important indicator of research steel plate texture.The effect of the crystal grain of rolled plate under tension and pressure simultaneously, therefore normal with some crystallographic direction <uvw> parallel roll to, also with some crystal face, { hkl} is parallel to the face of rolling, and forms plate texture simultaneously.Plate texture is conventional, and { hkl}<uvw> represents.

Usual mensuration is as follows along the texture development main process in steel plate thickness direction: adopt the methods such as mechanical lapping, Linear cut or chemical corrosion to carry out thinning to steel plate, after being thinned to specific thickness, measures the texture of surface of steel plate with X-ray diffractometer.After measuring the texture of different-thickness, the texture development situation along thickness of slab direction can be drawn.But there are following problems in this method:

1, sample preparation difficulty, obtain the sample of different-thickness position, need to use different thining method, the shortcoming of main method for making sample is as follows: mechanical polishing time is longer, and abrasive surface is difficult to remain a plane; Chemical corrosion is then difficult to control corrosion rate time and thickness; Linear cut needs to use special cutting equipment;

2, sense cycle is long, due to measuring process need sample thinning → X-ray measurement carries out repeatedly, therefore the cycle is longer;

3, the texture of limited several typical thickness positions can only be surveyed, as thickness of slab 1/4 and center etc., as the thickness position of measurement need be increased, then obviously can extend Measuring Time.

Therefore, by the texture of traditional X-ray measurement along steel plate thickness direction, there is the problems such as sample preparation difficulty, the cycle is long, measurement point is few, measuring error is larger.

In addition, traditional texture measurement method such as X-ray diffraction (XRD) can only measure the texture of macroscopic view, cannot measure the orientation relationship of microcell or each crystal grain.And measuring ODF figure with XRD, to carry out quantitative error calculated larger.The another kind of method measuring the method for texture adopts EBSD, i.e. Electron Back-Scattered Diffraction (electronbackscatterdiffraction), the grain orientation distribution plan of microcell can be measured, but there is the problem that measurement range is relatively little, error is larger.

Summary of the invention

Object of the present invention is exactly to overcome the deficiency existing for prior art, provides a kind of silicon steel texture measurement method having used EBSD, overcomes this problem that commercial measurement scope is little, error is larger simultaneously.

For achieving the above object, silicon steel texture measurement method of the present invention, step is as follows:

A) get silicon steel plate sample and be prepared into EBSD analytical sample;

B) with the distribution of orientations figure of the EBSD device measuring sample longitudinal section of scanning electron microscope outfit, thickness range, from surface of steel plate to thickness of slab center, measures the distribution of orientations figure in half thickness of slab region of at least 3 different-thickness positions;

C) measure rear analysis software, measured zone has been divided at least 10 homalographic regions along surface of steel plate to thickness of slab center, obtain ODF figure (orientation distribution function) from surface to the diverse location region at thickness of slab center by analysis successively;

D) by obtaining the ODF figure in diverse location region, software calculates each { hkl}<uvw> texture intensity by analysis, and each crystal face { hkl} intensity is should { all { intensity sums of hkl}<uvw> under hkl} crystal face, by { the density fraction f (hkl) of hkl} crystal face, i.e. f (hkl)=a certain { intensity/all { the intensity sums of hkl} crystal face of hkl} crystal face of formulae discovery below;

E) step C is repeated to the distribution of orientations map analysis in half thickness of slab region of other thickness positions) and D), to zones of different stack pile position { the density fraction f (hkl) of hkl} crystal face averages;

F) according to surface of steel plate to thickness of slab center zones of different density fraction f (hkl) mean value of hkl} crystal face, and use mapping software, obtain the data plot of Texture thickness of slab directional spreding.

Instant invention overcomes the defect that typical X-ray is measured, improve reliability and the precision of analysis, being a kind of relatively convenient texture method with accurately measuring along steel plate thickness direction, having the following advantages:

1) sample preparation is relatively convenient, after conventional metallographic specimen preparation method, then carries out the electropolishing removing stress, can complete EBSD sample preparation;

2) measure convenient and quick, use EBSD equipment can be easy to from surface of steel plate to the measurement of the cross section distribution of orientations figure at thickness of slab center;

3) be measure ODF figure for each region, more more accurate than measurement inverse pole figure, and, accurately can to calculate in ODF figure each { intensity of hkl}<uvw> texture, thus calculate each crystal face { density fraction of hkl}.And, measure ODF figure with EBSD and carry out quantitatively easily calculating.

Reliable results of the present invention is accurate, and the texture of measurement can reflect the distribution situation from surface of steel plate to thickness of slab center continuously, by measuring the data in multiple region, eliminating EBSD measured zone too small and cause the impact of error, making data more accurate.

Accompanying drawing explanation

Fig. 1 is the distribution of orientations figure at hot rolled silicon steel plates surface to thickness of slab center.

Fig. 2 is the distribution of orientations figure in homalographic region.

Fig. 3 is the ODF figure in Fig. 2 homalographic region.

Fig. 4 is the change curve in Texture thickness of slab direction.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.

In the following embodiment of the present invention, the analysis software of use is INCACrystal, is the powerful EBSD data acquisition and analysis software of several functions that Oxford Instruments provides.

Embodiment

For hot rolled silicon steel plates, introduce the texture method measured along thickness of slab direction, concrete steps are as follows:

A) longitudinal section along hot rolled silicon steel plates is prepared into EBSD analytical sample by following step: sample → inlay → polishing (corase grind and fine grinding) → mechanical buffing, finally uses electropolishing to remove stress;

B) with the distribution of orientations figure of the EBSD device measuring sample longitudinal section of scanning electron microscope outfit, thickness range is from surface of steel plate to thickness of slab center, and the distribution of orientations at hot rolled silicon steel plates surface to thickness of slab center as shown in Figure 1; Accurate in order to what ensure to measure, reduce and measure the too small and error that causes of area, measure the distribution of orientations figure in half thickness of slab region of 3 different-thickness positions;

C) rear analysis software has been measured, measured zone is divided into 10 homalographic regions along surface of steel plate to thickness of slab center, obtain successively by analysis scheming from surface to the ODF in the diverse location region at thickness of slab center, as shown in Figure 2, the ODF figure of one of them homalographic regional analysis result as shown in Figure 3 for the distribution of orientations in one of them homalographic region;

D) by obtaining the ODF figure in diverse location region, with analysis software calculate each hkl}<uvw> texture intensity, and each crystal face { hkl} intensity is should { all { intensity sums of hkl}<uvw> under hkl} crystal face; By { the density fraction f (hkl) of hkl} crystal face, i.e. f (hkl)=a certain { intensity/all { the intensity sums of hkl} crystal face of hkl} crystal face of formulae discovery below; Finally obtain the density fraction as η texture ({ 111} //ND), the Main Texture such as α texture (<110>//RD), γ texture (<001>//RD);

E) analysis of the distribution of orientations figure in another two and half thickness of slab regions repeats step C) and D), finally to zones of different stack pile position { the density fraction f (hkl) of hkl} crystal face averages;

F) according to surface of steel plate to thickness of slab center zones of different the mean value of the density fraction f (hkl) of hkl} crystal face, and use mapping software, obtain the data plot of Texture thickness of slab directional spreding, the texture development in Texture thickness of slab direction is as shown in Figure 4.

Claims (1)

1. a silicon steel texture measurement method, is characterized in that, the step of the method is as follows:

A) get silicon steel plate sample and be prepared into EBSD analytical sample;

B) with the distribution of orientations figure of the EBSD device measuring sample longitudinal section of scanning electron microscope outfit, thickness range, from surface of steel plate to thickness of slab center, measures the distribution of orientations figure in half thickness of slab region of at least 3 different-thickness positions;

C) measured rear analysis software, measured zone has been divided at least 10 homalographic regions along surface of steel plate to thickness of slab center, obtained successively by analysis scheming from surface to the ODF in the diverse location region at thickness of slab center;

D) by obtaining the ODF figure in diverse location region, software calculates each { hkl}<uvw> texture intensity by analysis, by formulae discovery { the density fraction f (hkl) of hkl} crystal face below, i.e. f (hkl)=a certain { intensity/all { intensity sums of hkl} crystal face of hkl} crystal face, it is wherein, a certain that { intensity of hkl} crystal face is { should own { the intensity sum of hkl}<uvw> under hkl} crystal face;

E) step C is repeated to the distribution of orientations map analysis in half thickness of slab region of other thickness positions) and D), to zones of different stack pile position { the density fraction f (hkl) of hkl} crystal face averages;

F) according to surface of steel plate to thickness of slab center zones of different density fraction f (hkl) mean value of hkl} crystal face, and use mapping software, obtain the data plot of Texture thickness of slab directional spreding.