阅读说明：本技术 一种x射线衍射法测定钢种残余奥氏体的标定方法 (Calibration method for measuring residual austenite of steel grade by X-ray diffraction method ) 是由 尤绍军 孙小东 王红伟 于 2021-02-04 设计创作，主要内容包括：一种涉及轴承热处理无损检测技术领域的X射线衍射法测定钢种残余奥氏体的标定方法,包含如下具体步骤：步骤一：残余奥氏体含量为零的轴承钢0#试样制备；步骤二：获得测量设备零位偏差值A；使用X射线衍射设备对制备好的残余奥氏体含量为零的0#试样进行检测,将得到的检测值A作为零位偏差值；步骤三：利用同一个X射线衍射设备对待测样品进行检测,待测样品的残余奥氏体含量Y=实际测量值B－零位偏差值A；该标定方法能对X射线衍射法测定的残余奥氏体含量进行修正,使测量结果更加准确。(A calibration method for measuring the residual austenite of a steel grade by an X-ray diffraction method relates to the technical field of bearing heat treatment nondestructive testing, and comprises the following specific steps: the method comprises the following steps: preparing a bearing steel 0# sample with zero residual austenite content; step two: obtaining a zero offset value A of the measuring equipment; detecting a prepared 0# sample with zero residual austenite content by using X-ray diffraction equipment, and taking an obtained detection value A as a zero offset value; step three: detecting a sample to be detected by using the same X-ray diffraction equipment, wherein the residual austenite content Y of the sample to be detected = actual measured value B-zero offset value A; the calibration method can correct the content of the residual austenite determined by the X-ray diffraction method, so that the measurement result is more accurate.)

1. A calibration method for measuring the residual austenite of a steel grade by an X-ray diffraction method is characterized by comprising the following steps: comprises the following steps:

the method comprises the following steps: preparing a bearing steel 0# sample with zero residual austenite content;

carrying out spheroidizing annealing on a high-carbon chromium bearing steel GCr15 or GCr15SiMn sample, and firstly putting the sample into a heating furnace for heating, wherein the heating temperature is as follows: 790 +/-10 ℃ and heat preservation time: 6 h-7 h; then opening a furnace cover and quickly cooling to 620 +/-10 ℃; then heating to 720 +/-10 ℃ along with the furnace, and keeping the temperature for 2-3 h; finally, the furnace is cooled to 600 +/-10 ℃ and discharged.

Step two: obtaining a zero offset value A of the measuring equipment; and (3) detecting the prepared 0# sample with zero residual austenite content by using an X-ray diffraction device, and taking the obtained detection value A as a zero offset value.

Step three: and detecting the sample to be detected by using the same X-ray diffraction equipment, wherein the residual austenite content Y of the sample to be detected = actual measured value B-zero offset value A.

2. The calibration method for measuring the retained austenite of the steel grade by the X-ray diffraction method according to claim 1, which is characterized in that: in step three, the absolute value of the actual measurement value of the sample to be tested is less than 6%.

3. The calibration method for measuring the retained austenite of the steel grade by the X-ray diffraction method as claimed in claim 2, which is characterized in that: and when the absolute value of the actual measured value of the sample to be measured is more than or equal to 6%, replacing the X-ray diffraction equipment, and calibrating again.

4. The calibration method for measuring the retained austenite of the steel grade by the X-ray diffraction method according to claim 1, which is characterized in that: the sample to be detected is required to be the same as the 0# sample in material.

5. The calibration method for measuring the retained austenite of the steel grade by the X-ray diffraction method according to claim 1, which is characterized in that: the holding time of the sample No. 0 in the heating stage in the step one is 6.5 h.

Technical Field

The invention relates to the technical field of bearing heat treatment nondestructive testing, in particular to a calibration method for determining the residual austenite of a steel grade by an X-ray diffraction method.

Background

According to the X-ray diffraction principle, the cumulative intensity of X-ray diffraction lines of a certain phase is improved along with the increase of the relative content of the phase in a sample, the content of residual austenite in steel is calculated by measuring the cumulative intensity of the diffraction lines of the martensite phase and the austenite phase of bearing steel, but equipment and calculation deviation exists in the measuring process, and the deviation is generally between 1% and 2%; the precision bearing, the rolling mill bearing and the wind power bearing have low requirements on the content of the retained austenite in steel, generally the requirement is not more than 3%, accurate measurement results cannot be obtained under the deviation, and a calibration method is needed to correct the measurement results so as to accurately obtain the content of the retained austenite of the sample.

Disclosure of Invention

In order to overcome the defects in the background art, the invention discloses a calibration method for measuring the residual austenite of a steel grade by an X-ray diffraction method, which can correct the residual austenite content measured by the X-ray diffraction method and ensure that the measurement result is more accurate.

In order to achieve the purpose, the invention adopts the following technical scheme:

a calibration method for measuring the residual austenite of a steel grade by an X-ray diffraction method comprises the following specific steps:

the method comprises the following steps: preparing a bearing steel 0# sample with zero residual austenite content; carrying out spheroidizing annealing on a high-carbon chromium bearing steel GCr15 or GCr15SiMn sample, and firstly putting the sample into a heating furnace for heating, wherein the heating temperature is as follows: 790 +/-10 ℃ and heat preservation time: 6 h-7 h; then opening a furnace cover and quickly cooling to 620 +/-10 ℃; then heating to 720 +/-10 ℃ along with the furnace, and keeping the temperature for 2-3 h; finally, the furnace is cooled to 600 +/-10 ℃ and discharged.

Step two: obtaining a zero offset value A of the measuring equipment; and (3) detecting the prepared 0# sample with zero residual austenite content by using an X-ray diffraction device, and taking the obtained detection value A as a zero offset value.

Step three: and detecting the sample to be detected by using the same X-ray diffraction equipment, wherein the residual austenite content Y of the sample to be detected = actual measured value B-zero offset value A.

Further, in step three, the absolute value of the actual measurement value of the sample to be measured is less than 6%.

Further, when the absolute value of the actual measurement value of the sample to be measured is greater than or equal to 6%, replacing the X-ray diffraction equipment, and calibrating again.

Furthermore, the material of the sample to be detected is the same as that of the 0# sample.

Further, the holding time of the sample No. 0 in the heating stage in the step one is 6.5 h.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

the calibration method for determining the residual austenite of the steel grade by the X-ray diffraction method can more accurately detect the residual austenite content in the steel, solves the problem that the X-ray diffraction method cannot accurately obtain the residual austenite content of bearing parts with low requirements on the residual austenite content such as precision bearings, rolling mill bearings, wind power bearings and the like, is convenient to provide technical support for the optimization and adjustment of the heat treatment process, and meets the requirements of users.

Drawings

None.

Detailed Description

The present invention will be explained in detail by the following examples, which are disclosed for the purpose of protecting all technical improvements within the scope of the present invention, and are not limited to the following examples:

the first embodiment is as follows:

a calibration method for measuring the residual austenite of a steel grade by an X-ray diffraction method comprises the following specific steps:

the method comprises the following steps: preparing a bearing steel 0# sample with zero residual austenite content; firstly, spheroidizing annealing is carried out on a GCr15 or GCr15SiMn sample of high-carbon chromium bearing steel, and the sample is put into a heating furnace for heating at the following temperature: 780 ℃, heat preservation time: 6 h; then opening a furnace cover and quickly cooling to 610 ℃; then heating to 710 ℃ along with the furnace, and keeping the temperature for 2 hours; finally, furnace cooling is carried out to 590 ℃ and discharging is carried out;

step two: obtaining a zero offset value A of the measuring equipment; detecting a prepared 0# sample with zero residual austenite content by using X-ray diffraction equipment, and taking an obtained detection value A as a zero offset value;

step three: detecting a sample to be detected by using the same X-ray diffraction equipment, wherein the sample to be detected needs to be the same as the selected 0# sample in material, and the residual austenite content Y of the sample to be detected = the actual measured value B-zero offset value A; in addition, in order to ensure more accurate calibration, in step three, the absolute value of the actual measurement value of the sample to be measured needs to be less than 6%, and generally, according to the deviation requirement, the austenite of the sample to be measured only has the significance of calibration if the austenite is less than 6%; according to the requirement, when the absolute value of the actual measurement value of the sample to be measured is greater than or equal to 6%, based on the uncertainty of the measurement deviation of the X-ray diffraction equipment, the proper X-ray diffraction equipment can be selected and replaced, and calibration is carried out again.

Example two:

the difference from the first embodiment is that the first step:

the method comprises the following steps: preparing a bearing steel 0# sample with zero residual austenite content; carrying out spheroidizing annealing on a high-carbon chromium bearing steel GCr15 or GCr15SiMn sample, and firstly putting the sample into a heating furnace for heating, wherein the heating temperature is as follows: 790 ℃, heat preservation time: 6.5 h; then opening a furnace cover and quickly cooling to 620 ℃; then the temperature is raised to 720 ℃ along with the furnace, and the heat preservation time is 2.5 h; finally, the furnace is cooled to 600 ℃ and taken out of the furnace.

Example three:

the difference from the first embodiment is that the first step:

the method comprises the following steps: preparing a bearing steel 0# sample with zero residual austenite content; carrying out spheroidizing annealing on a high-carbon chromium bearing steel GCr15 or GCr15SiMn sample, and firstly putting the sample into a heating furnace for heating, wherein the heating temperature is as follows: 800 ℃, heat preservation time: 7 h; then opening a furnace cover and quickly cooling to 630 ℃; then the temperature is raised to 730 ℃ along with the furnace, and the heat preservation time is 3 hours; finally, the furnace is cooled to 610 ℃ and taken out.

Residual austenite content% by X-ray diffraction method

The present invention is not described in detail in the prior art.