Device and method for detecting forming quality of electron beam cladding layer

Abstract

The invention discloses a device and a method for detecting the forming quality of an electron beam cladding layer, which are characterized in that an infrared thermal imager is attached to an electron gun of electron beam processing equipment, and the mounting position of the infrared thermal imager in the electron beam processing equipment is disclosed; the method comprises the following steps: performing surface modification on a test piece with a preset coating by utilizing electron beam cladding, so that coating powder is completely molten, and the surface of a matrix is molten by a certain depth to obtain a cladding layer with good metallurgical bonding; according to the present invention, the cladding layer is subjected to infrared thermal imaging detection, and the coating temperature field distribution diagram is collected so as to lock the crack generation position of the electron beam cladding coating lower substrate, such that the crack of the cladding layer lower substrate can be timely and effectively detected so as to improve the electron beam cladding forming quality.

Description

Technical Field

[0001] The invention relates to the technical field of substrate crack detection under electron beam cladding coating, in particular to a device for detecting the forming quality of an electron beam cladding layer. Background Art

[0002] Electron beam cladding technology uses a high-energy-density electron beam as a heat source. Through thermal spraying, adhesives, pressing and other treatment methods, a layer of alloyed powder coating with a thickness ranging from several microns to several millimeters and with special physical and chemical properties is pre-coated on the surface of the substrate. When the high-energy-density electron beam acts on the surface of the material, the incident energy is deposited, causing the surface temperature to rise rapidly, triggering melting, vaporization and melt eruption. After the incident energy ends, the surface of the workpiece solidifies and cools rapidly, making it inevitable that there will be some residual stress in the coating and the substrate, and thus some microcracks will often appear in the coating and the substrate.

[0003] Micro cracks are directly related to the service life and safety performance of components, so it is very necessary to detect cracks in coatings and substrates. The cracks in coatings visible to the naked eye can be solved by appearance inspection, while substrate cracks under the coating that are invisible to the naked eye are a hot topic of current research.

[0004] The infrared thermal imaging method detects crack defects in the substrate under the coating. Its principle is based on the characteristic that any material above absolute zero (-273°C) will emit thermal radiation energy. It uses external low-frequency (20-40kHz) ultrasonic vibration waves as the excitation source. When the ultrasonic wave propagates at the crack, due to its hysteresis effect and thermoelastic effect, it will cause the crack contact surface to rub against each other and generate heat, thereby causing the surface temperature at the crack position to rise and the thermal radiation to increase. Combined with the infrared thermal imager to monitor and record the material surface temperature field distribution map in real time, it can be used for crack feature extraction and analysis to achieve surface crack detection. Summary of the invention

[0005] The object of the present invention is to provide a device and method for detecting the forming quality of an electron beam cladding layer, which can timely detect the location of substrate cracks under the electron beam cladding coating and improve the service life and safety performance of the test piece.

[0006] To achieve the above-mentioned purpose, the present invention provides a device and method for detecting the forming quality of an electron beam cladding layer, including.

[0007] In the vacuum chamber of an electron beam processing machine, an infrared thermal imaging camera is attached to the electron gun.

[0008] The electron beam cladding technology is used to modify the surface of the pre-coated specimen to obtain a metallurgically bonded cladding layer.

[0009] The cladding layer is inspected by infrared thermal imaging, the temperature field distribution diagram of the coating is collected, and the location of the substrate cracks under the electron beam cladding coating is obtained.

[0010] Among them, in the vacuum chamber of the electron beam processing equipment, the infrared thermal imager is attached to the electron gun, including: the rated parameters of the selected electron beam processing equipment are scanning power of 0 to 9KW, acceleration voltage of 60KV, scanning beam current of 0 to 150mA, focusing current of 0 to 1000mA, scanning frequency of 0.1 to 2000Hz, and scanning amplitude of 0 to 150mm.

[0011] The infrared thermal imager selected is the Lynx R uncooled short-wave infrared linear camera series.

[0012] The electron beam cladding technology is used to modify the surface of the pre-coated substrate to obtain a metallurgically bonded cladding layer, including: the process parameters emitted from the electron gun range from a vacuum chamber vacuum degree of 3.5×10 -2 The electron beam with the acceleration voltage of 0-60 kV, the scanning beam current of 40-80 mA, the focusing current of 300-380 mA and the scanning speed of 400-800 mm / min acts on the substrate surface of the pre-coating to melt all the coating powder and melt the substrate surface to a certain depth to obtain a metallurgically bonded cladding layer.

[0013] Among them, infrared thermal imaging detection is carried out on the cladding layer, and the temperature field distribution map of the coating is collected to obtain the location of the substrate crack under the electron beam cladding coating, including: after the electron beam is scanned, the test piece returns to the position before processing, and the infrared thermal imager is used to irradiate and collect the temperature field distribution map of the coating to find the location of the crack defect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the schematic diagram of the electron beam cladding layer forming quality detection device - infrared thermal imaging detection device. Figure 2 This is the surface thermal image of the infrared thermal imager, which clearly shows the locations of two cracks on the substrate under the electron beam cladding coating. Implementation

[0015] The following is a further description of the specific examples of the present invention. Obviously, the examples described are only part of the embodiments of the present invention and do not represent all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Embodiment 1: This embodiment provides a device and method for detecting the forming quality of an electron beam cladding layer.

[0017] The first step is to select the assembly equipment: select the infrared thermal imager of the Lynx R uncooled short-wave infrared linear camera series, and the rated parameters of the selected electron beam processing equipment are scanning power of 0-9KW, acceleration voltage of 60KV, scanning beam current of 0-150mA, focusing current of 0-1000mA, scanning frequency of 0.1-2000Hz, and scanning amplitude of 0-150mm. In the vacuum chamber of the electron beam processing equipment, attach the infrared thermal imager to the electron gun. Figure 1 shown.

[0018] The second step is the selection of matrix materials: 316 stainless steel with chemical composition (mass fraction%) of Cr:16-18, Ni:10-14, Mo:2-3, Mn<2, C:<0.08, Si<1, S<0.03, p<0.03, Fe:Bal is selected, and it is cut into rectangular blocks with the size requirement of 50mm×30mm×10mm (length×width×thickness) by electric spark wire cutting. Both sides of the sample are polished with 600# sandpaper, mainly to remove the oxide scale, but the flatness of the matrix needs to be ensured. Then wipe both sides with cotton balls containing alcohol, and finally wipe both sides clean with cotton balls soaked in acetone solution and blow dry to ensure that impurities such as grease and rust on the surface of the matrix are removed.

[0019] The third step is to pre-set the coating material: the chemical composition (mass fraction%) of the selected cobalt-based powder is Cr: 15-18, Mo: 26-29, C: <0.08, Fe: <2, Si: 2-3.5, Ni: <1, Co: Bal. Then, the thermal spraying process is adopted, the mixed powder is put into the powder feeder, and the powder is fed by an external rotary powder feeder for thermal spraying pre-setting. The spraying process parameters are: current 412A, voltage 36V, main gas (Ar) flow rate 1400L·h -1 , auxiliary gas (H2) 6 L·h -1 , powder delivery flow rate 200 L·h -1 , spraying distance 100mm, spray gun moving speed 100mm·s -1 , coating thickness 300. This mixed coating material is pre-placed on the surface of 316 stainless steel substrate.

[0020] The fourth step is electron beam cladding: the sample is placed in the vacuum chamber of the electron beam processing equipment, the sample is fixed on the workbench, and the coating is clad by vertical irradiation of the electron beam with a beam spot diameter of 6mm. The cladding parameters are: power of 1500W, scanning speed of 380mm / min, beam spot diameter of 6mm. After the coating is clad by the electron beam, a metallurgical bonding layer of the substrate micro-melted coating is formed, thereby obtaining the required cladding layer.

[0021] After obtaining the electron beam cladding modified layer, infrared thermal imaging detection was performed on the alloyed cladding layer on the surface of 316 stainless steel.

[0022] After irradiation with the infrared thermal imager, the temperature field distribution diagram of the coating is collected to find the location of the substrate crack defect under the coating. Figure 2 shown.

[0023] The specific embodiments provided herein are only used to illustrate the methods and core concepts of the present invention and should not be construed as limiting the scope of the present invention. A person of ordinary skill in the art can understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A device and method for detecting the forming quality of an electron beam cladding layer, characterized in that: include: Attaching an infrared thermal imager to the electron gun of an electron beam processing device; The electron beam cladding technology is used to modify the surface of the pre-coated specimen to obtain a metallurgically bonded cladding layer; The cladding layer is inspected by infrared thermal imaging, the temperature field distribution diagram of the coating is collected, and the location of the substrate cracks under the electron beam cladding coating is obtained.

2. The device and method for detecting the forming quality of the electron beam cladding layer according to claim 1 are characterized in that: The method of attaching the infrared thermal imager to the electron gun of the electron beam processing equipment specifically includes: selecting the Lynx R uncooled short-wave infrared linear camera series for the infrared thermal imager; selecting the electron beam processing equipment with rated parameters of scanning power of 0 to 9 KW, acceleration voltage of 60 KV, scanning beam current of 0 to 150 mA, focusing current of 0 to 1000 mA, scanning frequency of 0.1 to 2000 Hz, and scanning amplitude of 0 to 150 mm.

3. The device and method for detecting the forming quality of an electron beam cladding layer according to claim 1, characterized in that: The electron beam cladding technology is used to modify the surface of the pre-coated test piece to obtain a metallurgically bonded cladding layer, specifically including: the process parameter range emitted by the electron gun is the vacuum degree of the vacuum chamber 3.5×10 -2 The electron beam with a 0.04-0.08 Pa, an accelerating voltage of 0-60 kV, a scanning beam current of 40-80 mA, a focusing current of 300-380 mA, and a scanning speed of 400-800 mm / min acts on the surface of the substrate with the pre-coating, and the coating powder is completely melted. The surface of the substrate is melted to a certain depth to obtain a metallurgically bonded cladding layer.

4. The device and method for detecting the forming quality of an electron beam cladding layer according to claim 1, characterized in that: The infrared thermal imaging detection is performed on the cladding layer, the coating temperature field distribution map is collected, and the position of the substrate crack under the electron beam cladding coating is obtained, which specifically includes: after the electron beam is scanned, the test piece returns to the position before processing, and the infrared thermal imager is used to irradiate and collect the coating temperature field distribution map to find the crack defect position.

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