RU2618602C1 - Method for x-ray control parts of gas turbine engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: they carry out the removal of X-ray-controlled items on the expected fracture surface, determining a parameter that depends on the operating time items, and its comparison with a limit value, while as a parameter that depends on the details of use, use the background area of the X-ray spectrum S_f, defined by a given relationship.

EFFECT: increased productivity of the process control of parts of a gas turbine engine non-destructive way.

4 dwg

Description

The invention relates to non-destructive methods of x-ray control and can be used to assess the technical condition of repair parts of a gas turbine engine (GTE) made of titanium alloys in laboratory and factory conditions.

The closest is the method of x-ray structural inspection of the details of a gas turbine engine (G01N 23/00, publ. 07/20/2013), including the removal of the x-ray from the controlled part on the alleged surface of destruction, determining a parameter depending on the operating time of the part, and comparing it with the limit value .

The disadvantage of this method is that the method is time-consuming, expensive and requires accurate positioning of the disks using specialized equipment to account for the individual texture of the disk.

The technical result, the proposed solution is aimed at, is to increase the productivity of the technological process for controlling gas-turbine engine parts in a non-destructive way, by simplifying the methods for calculating X-ray diffraction data, there is no need to accurately position the parts during measurement, and there is no need to use specialized equipment to take into account the individual texture of gas-turbine engine parts from titanium alloys.

The technical result is achieved by the fact that in the method of x-ray structural control of parts of a gas turbine engine, which includes taking an x-ray from a controlled part on an assumed fracture surface, determining a parameter depending on the operating time of the part, and comparing it with a limiting value, in contrast to the known parameter that depends on the operating time of the part, use the parameter of the background area of the x-ray spectrum S _f , determined by the dependence

,

,

where X _i , X _i-1 - the coordinates of the channel of the detector scale;

i is the channel number of the detector;

I _i - X-ray intensity corresponding to X _i on the detector scale, determined by the dependence

,

,

a , b, c - numerical coefficients, then compare the value of the background area parameter of the X-ray spectrum S _f with the limit value of S _fc , the part is returned to operation if the value of the background area parameter of the X-ray spectrum S _{f is} greater than the limit value of S _fc , or the part is taken out of service if the value of the parameter of the background area of the x-ray spectrum S _f less than the limit value S _fc .

The drawings show:

FIG. 1 - x-ray spectrum (x-ray) at the end of the KND disk from alloy VT3-1;

FIG. 2 - graphs of the dependence of the background parameter on the operating time in cycles on samples from the CPV disk before and after life tests for low-cycle fatigue (MCU);

FIG. 3 - graphs of the dependence of the background parameter at the end of the groove of the KND disk with the conditional number No. 1 before and after life tests at the UIR-3 installation of 2000 cycles.

FIG. 4 - graphs of the dependence of the background parameter at the end of the groove of the KND disk with the conditional number No. 2 before and after life tests at the UIR-3 installation of 320 cycles.

The method is as follows.

A controlled part on the alleged surface of destruction is subjected to x-ray radiation. The radiation comes from the reflecting plane (11.0) without background when using Ti-K _α titanium radiation and from the reflecting plane (01.3) without background when using Ti-K _β titanium radiation, and the area parameter is used as a parameter depending on the operating time of the part X-ray spectrum background S _f . To determine the background area of the X-ray spectrum S _f , the X-ray spectrum is recorded by an X-ray diffractometer in risk areas (in areas of the part where destruction occurs during operation and life tests) under the same X-ray modes using titanium radiation without a β filter in the range of Wulf-Bragg angles 2θ (the range can be set from 136 degrees to 155 degrees) and the calculation as follows:

where X _i , X _i-1 - the coordinates of the channel of the detector scale;

i is the channel number of the detector;

I _i - X-ray intensity corresponding to X _i on the detector scale, determined by the dependence

,

,

a , b, c are numerical coefficients.

Next, the value of the parameter of the background area of the x-ray spectrum S _{f is} compared with the limiting value S _fc . The part is returned to operation if the value of the background area parameter of the X-ray spectrum S _{f is} greater than the limit value of S _fc , or the part is decommissioned if the value of the background area parameter of the X-ray spectrum S _{f is} less than the limit value of S _fc .

Example.

Using an X-ray diffractometer, the parameters of the X-ray spectrum are measured (Fig. 1), for example, at the ends of the groove of the disk of a low-pressure compressor (KND) made of VT3-1 alloy, while measurements at the ends of the groove are performed both at the output of the disk and at the input of the disk . The number of channels on the detector scale is 512, and the radius of the arc of the goniometer is 50 mm.

In FIG. Figure 2 shows a graph of the dependence of the background parameter on the operating time in cycles of samples from the low pressure switch before and after the resource tests for low-cycle fatigue (MCU). All samples are made of the castle part of the disk of the 1st stage of the KND disk for testing at the MCU. Testing of samples at the MCU was carried out in stages after 3000 cycles (until failure). The total operating time of the samples ranged from approximately 22,400 to 23,400 cycles. From the graph (Fig. 2) it is seen that on the samples (the right side of the groove relative to the output of the disk) with an operating time after 18000 cycles there is a sharp decrease in the background parameter S _f . A significant change in this parameter occurs at the moment when a defect occurs in the surface layer of the material with a depth of 5-7 μm (this depth is comparable with the penetration depth of X-rays when using a titanium tube). As soon as the defect reaches the surface, the parameter S _f increases almost to the initial value.

In FIG. Figure 3 shows, as an example, the distribution of the background parameter S _f at the end of the groove of the KND disk with conditional number No. 1 before (the state of the disk after operation in the engine with the operating time of 14551 hours / 5321 cycles) and after life tests at the UIR-3 installation of 2000 cycles. From the graph (Fig. 3) it can be seen that on disk No. 1 the value of S _f at all the studied points above the critical value. After the Lumi-control, no defects were found, disc No. 1 can be considered repairable.

As the following example (Fig. 4), we show a graph of the distribution of the background parameter S _f at the end of the groove of the KND disk with conditional number 2 before (the state of the disk after operation as part of the engine with an operating time of 11907 hours / 5794 cycles) and after life tests at the installation UIR-3 320 cycles. From the graph (Fig. 4) it is seen that at the ends of the grooves of the KND disk with numbers 5 ÷ 11 after life tests at the UIR-3 installation, a significant change in the background parameter S _f occurs On this disc, after 18 flight test cycles using the Lum-control method, a crack was detected.

Thus, this method of x-ray structural inspection to determine the background parameter of the x-ray spectrum can be used to defect GTE repair parts at an earlier period of defect detection in the surface layers of the part, while other methods of defectoscopy are ineffective and to determine maintainability.

As a result, due to the simplification of the methods for calculating X-ray diffraction data, the absence of the need for accurate positioning of parts during measurement, and the absence of the need to use specialized equipment to take into account the individual texture of parts of gas turbine engines made of titanium alloys, this technical solution allows to increase the productivity of the technological process of controlling parts in a non-destructive way.

Claims (7)

A method of X-ray structural control of parts of a gas turbine engine, including taking an X-ray diffraction pattern from a controlled part on an assumed fracture surface, determining a parameter depending on the part’s life, and comparing it with a limiting value, characterized in that the background area parameter is used as a parameter depending on the operating time X-ray spectrum S _f determined by the dependence

where X _i , X _i-1 - the coordinates of the channel of the detector scale; i is the channel number of the detector; I _i - the intensity of x-ray radiation corresponding to the detector scale, determined by the dependence

a , b, c - numerical coefficients, then compare the value of the parameter of the background area of the X-ray spectrum S _f with the limit value of S _fc , the part is returned to operation if the value of the parameter of the background area of the X-ray spectrum S _{f is} greater than the limit value of S _fc , or the part is taken out of service if the value of the parameter of the background area of the x-ray spectrum S _f less than the limit value S _fc .

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