Preparation process of gas turbine blade

Abstract

The invention discloses a preparation technology of a gas turbine blade. The preparation technology comprises the steps that firstly, a blade base material and brazing filler metal are selected; 2, surface treatment is conducted, specifically, the welding part is mechanically polished, and a surface oxide layer is removed; thirdly, brazing filler metal is prepared, wherein the brazing filler metal is cut into a proper shape, and the thickness is controlled to range from 0.1 mm to 0.3 mm; 4, assembling and clamp designing are conducted, specifically, all assemblies of the movable blade are pre-assembled according to design requirements, and it is ensured that the gap is controlled to be 0.05-0.1 mm; 5, brazing process parameters are set; 6, welding post-treatment: carrying out heat treatment on a welding joint to eliminate welding stress, and 7, quality detection: carrying out nondestructive detection on the welding joint to ensure that the welding quality meets the standard. According to the brazing process, the welding quality of the movable blade of the gas turbine and the using performance of the movable blade in the high-temperature and high-pressure environment can be remarkably improved, and the brazing process has good application prospects.

Description

Technical Field

[0001] The invention relates to a preparation process of a gas turbine blade, belonging to the technical field of gas turbine preparation. Background Art

[0002] Gas turbine blades work under high temperature and high pressure, requiring them to have excellent strength, heat resistance and corrosion resistance. Existing welding technology has limitations in high temperature strength and durability, so a new brazing process is needed to improve the performance of blades. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a preparation process for gas turbine blades, thereby solving the above-mentioned technical problems.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a preparation process of a gas turbine blade, comprising the following steps: Step 1: Select the blade substrate and solder; ensure that the material surface is clean and free of oil, oxides and impurities; Step 2: Surface treatment: Mechanically grind the welding parts to remove the surface oxide layer, and control the roughness to Ra0.8-1.6 µm. Use chemical cleaning agents to chemically clean the surface to ensure that no pollutants remain; Step 3: Preparation of solder: Cut the solder into appropriate shapes with a thickness between 0.1-0.3 mm; arrange the solder position reasonably according to the welding structure; Step 4: Assembly and fixture design: Pre-assemble the components of the moving blade according to the design requirements to ensure that the gap is controlled within 0.05-0.1 mm; design a special fixture to ensure the stability of the components during the welding process; Step 5: Brazing process parameter settings: Heating method: use induction heating or laser heating; Heating temperature: control the heating temperature between 800-1100°C, the specific temperature depends on the brazing material selection; Insulation time: keep at the heating temperature for 5-30 minutes to ensure that the brazing material is fully melted and penetrated; Cooling method: natural cooling or water cooling, the cooling rate is controlled within 20°C / min; Step 6: Post-welding treatment: Heat treat the welded joint to eliminate welding stress. The heat treatment temperature is set at 600-800°C and the insulation time is 1-2 hours. Perform surface treatment to remove oxides and dirt after welding, and polish if necessary. Step 7: Quality inspection: Use ultrasonic testing (UT) and X-ray testing (RT) to perform non-destructive testing on the welded joints to ensure that the welding quality meets the standards; perform mechanical property tests, including tensile tests and hardness tests, to verify the mechanical properties of the welded joints.

[0005] Furthermore, the blade substrate is made of nickel-based alloy or cobalt-based alloy; the solder is made of silver-based solder or nickel-based solder.

[0006] Furthermore, in step six, the process parameters of the heat treatment are: heating rate 15-25°C / min, maintaining temperature 700°C, holding time 1.5h, cooling rate 5-25°C / min.

[0007] The beneficial effect of the present invention is that the brazing process provided by the present invention can significantly improve the welding quality of gas turbine rotor blades and their performance under high temperature and high pressure environments, and has good application prospects. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail by examples below. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0009] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0010] In this embodiment, a preparation process of a gas turbine blade includes the following steps: Step 1: Select the blade substrate and solder; ensure that the material surface is clean and free of oil, oxides and impurities; Step 2: Surface treatment: Mechanically grind the welding parts to remove the surface oxide layer, and control the roughness to Ra0.8-1.6 µm. Use chemical cleaning agents to chemically clean the surface to ensure that no pollutants remain; Step 3: Preparation of solder: Cut the solder into appropriate shapes with a thickness between 0.1-0.3 mm; arrange the solder position reasonably according to the welding structure; Step 4: Assembly and fixture design: Pre-assemble the components of the moving blade according to the design requirements to ensure that the gap is controlled within 0.05-0.1 mm; design a special fixture to ensure the stability of the components during the welding process; Step 5: Brazing process parameter settings: Heating method: use induction heating or laser heating; Heating temperature: control the heating temperature between 800-1100°C, the specific temperature depends on the brazing material selection; Insulation time: keep at the heating temperature for 5-30 minutes to ensure that the brazing material is fully melted and penetrated; Cooling method: natural cooling or water cooling, the cooling rate is controlled within 20°C / min; Step 6: Post-welding treatment: Heat treat the welded joint to eliminate welding stress. The heat treatment temperature is set at 600-800°C and the insulation time is 1-2 hours. Perform surface treatment to remove oxides and dirt after welding, and polish if necessary. Step 7: Quality inspection: Use ultrasonic testing (UT) and X-ray testing (RT) to perform non-destructive testing on the welded joints to ensure that the welding quality meets the standards; perform mechanical property tests, including tensile tests and hardness tests, to verify the mechanical properties of the welded joints.

[0011] In this embodiment, preferably, the blade substrate is made of nickel-based alloy or cobalt-based alloy; and the solder is made of silver-based solder or nickel-based solder.

[0012] Preferably, in step six of the present embodiment, the process parameters of the heat treatment are: heating rate 15-25°C / min, holding temperature 700°C, holding time 1.5h, cooling rate 5-25°C / min.

[0013] The brazing process provided by the present invention can significantly improve the welding quality of gas turbine rotor blades and their performance under high temperature and high pressure environments, and has good application prospects.

[0014] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for preparing a gas turbine blade, characterized in that: The following steps are involved: Step 1: Select the blade substrate and solder; ensure that the material surface is clean and free of oil, oxides and impurities; Step 2: Surface treatment: Mechanically grind the welding parts to remove the surface oxide layer, and control the roughness to Ra 0.8-1.6 µm. Use chemical cleaning agents to chemically clean the surface to ensure that no contaminants remain; Step 3: Preparation of solder: Cut the solder into appropriate shapes with a thickness between 0.1-0.3 mm; arrange the solder position reasonably according to the welding structure; Step 4: Assembly and fixture design: Pre-assemble the components of the moving blade according to the design requirements to ensure that the gap is controlled within 0.05-0.1 mm; design a special fixture to ensure the stability of the components during the welding process; Step 5: Brazing process parameter settings: Heating method: use induction heating or laser heating; Heating temperature: control the heating temperature between 800-1100°C, the specific temperature depends on the brazing material selection; Insulation time: keep at the heating temperature for 5-30 minutes to ensure that the brazing material is fully melted and penetrated; Cooling method: natural cooling or water cooling, the cooling rate is controlled within 20°C / min; Step 6: Post-welding treatment: Heat treat the welded joint to eliminate welding stress. The heat treatment temperature is set at 600-800°C and the insulation time is 1-2 hours. Perform surface treatment to remove oxides and dirt after welding, and polish if necessary. Step 7: Quality inspection: Use ultrasonic testing (UT) and X-ray testing (RT) to perform non-destructive testing on the welded joints to ensure that the welding quality meets the standards; perform mechanical property tests, including tensile tests and hardness tests, to verify the mechanical properties of the welded joints.

2. A process for preparing a gas turbine blade according to claim 1, characterized in that: The blade substrate is made of nickel-based alloy or cobalt-based alloy; the solder is made of silver-based solder or nickel-based solder.

3. The process for preparing a gas turbine blade according to claim 1, characterized in that: In step six, the process parameters of the heat treatment are: heating rate 15-25°C / min, holding temperature 700°C, holding time 1.5h, cooling rate 5-25°C / min.