Repair method for overtemperature damage of flame tube

Abstract

The invention discloses a method for repairing overtemperature damage of a flame tube, which comprises the following steps of: detecting the thickness of an outlet ring and a conical part by using an ultrasonic detection device, recording a size numerical value and marking a height needing to be replaced; cutting and blanking, rounding, resistance spot welding, brazing, discharge hole machining and necessary shape correction are carried out by adopting the same material of a flame tube body or a substitute material with equivalent performance, and the outlet ring assembly is prepared; according to the thickness condition of the body, a welding gap is reserved, pre-welding cleaning is carried out, spot welding positioning and fixing are carried out on an outlet ring welding tool, and a checking fixture is adopted to confirm that the overall height meets the requirement; carrying out continuous cladding welding under argon back pressure; stress relief heat treatment is carried out; and the repaired part is subjected to sanding cleaning and penetrant testing, and the normal repairing technological process is returned after the repaired part is qualified. According to the method, the composite cooling structure flame tube seriously damaged by overtemperature can be repaired, the repaired flame tube has the re-operation condition, the service life of parts is prolonged, and the operation and maintenance cost of a unit is reduced.

Description

Technical Field

[0001] The invention relates to a method for repairing a flame tube component, in particular to a method for repairing over-temperature damage of a flame tube. Background Art

[0002] The flame tube is the core component of the gas turbine, and is related to many indicators such as the heat consumption, performance and emissions of the gas turbine. Severe damage to the flame tube during operation may lead to particularly serious consequences. For the dual considerations of safety and reliability, special repair requirements are put forward for the flame tube repair process. The flame tube is a thin-walled part. For the thin wall in the local area, argon arc welding can be used to repair it directly. When serious damage occurs due to overheating, the whole part is often replaced. This maintenance method causes high operation and maintenance costs. Therefore, a reasonable and effective repair process is urgently needed to reduce the operation and maintenance costs of the flame tube and even the unit. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to shorten the maintenance time and reduce the maintenance cost, and to propose a reasonable and efficient repair method to repair the composite cooling structure flame tube that is severely damaged by overheating. After the repair, it is ready for operation again, thereby increasing the service life of the components and reducing the operation and maintenance cost of the unit.

[0004] Technical solution: A method for repairing flame tube overheating damage, comprising the following steps:

[0005] Step 1: Use an ultrasonic testing device to detect the thickness of the outlet ring and the cone, record the size value and mark the height that needs to be replaced; wherein the parameters of the ultrasonic testing device are set as follows: basic gain: 90-95dB, sound speed determined according to the component structure and parent material: 4000m / s-5000m / s, compensation: 9-13dB;

[0006] Step 2: Use the same material as the flame tube body or an alternative material with equivalent performance to carry out cutting, rounding, resistance spot welding, brazing, discharge hole processing and necessary correction to prepare the outlet ring assembly; wherein the parameters of the brazing heat treatment are set as follows: heating rate 32-38℃ / min, holding temperature 1250-1290℃, cooling rate 14-19℃ / min;

[0007] Step 3: Refer to the thickness of the body, reserve welding gap, perform pre-welding cleaning, spot weld positioning and fix on the outlet ring welding fixture, and use a gauge to confirm that the overall height meets the requirements;

[0008] Step 4: Perform continuous cladding welding under argon back pressure, pay attention to controlling heat input and deformation, check the weld area after welding, and grind or calibrate it if necessary;

[0009] Step 5: Perform stress relief heat treatment to avoid cracks in the weld area due to stress concentration;

[0010] Step 6: Sandblast and clean the repaired parts and conduct penetration testing. If qualified, return to the normal repair process. Among them, the sandblasting parameters are set before penetration testing: medium aluminum oxide corundum, pressure 0.7-0.9bar, distance 40-70mm, and be careful not to continue to spray at a fixed point.

[0011] Further: the setting parameters of the discharge hole processing in step 2 are as follows: electrode diameter: 1.6-1.9mm, high pressure water pressure: 83-86kg / cm 2 , current: 6.8-8.2A, voltage: 23-26V.

[0012] Beneficial effects: The present invention can repair the composite cooling structure flame tube that is severely damaged by overheating, so that it can be operated again after repair, thereby increasing the service life of the components and reducing the operation and maintenance costs of the unit. DETAILED DESCRIPTION Specific embodiment 1

[0014] A method for repairing flame tube over-temperature damage includes the following steps:

[0015] Step 1: Use an ultrasonic testing device to detect the thickness of the outlet ring and the cone, record the size value and mark the height that needs to be replaced; wherein the parameters of the ultrasonic testing device are set as follows: basic gain: 90dB, sound speed determined according to the component structure and the parent material: 5000m / s, compensation: 13dB;

[0016] Step 2: Use the same material as the flame tube body or an alternative material with equivalent performance to carry out cutting, rounding, resistance spot welding, brazing, discharge hole processing and necessary correction to prepare the outlet ring assembly; the parameters of the brazing heat treatment are set as follows: heating rate 32℃ / min, holding temperature 1250℃, cooling rate 19℃ / min; the setting parameters of the discharge hole processing are as follows: electrode diameter: 1.6mm, high pressure water pressure: 83kg / cm 2 , current: 6.8A, voltage: 26V;

[0017] Step 3: Refer to the thickness of the body, reserve welding gap, perform pre-welding cleaning, spot weld positioning and fix on the outlet ring welding fixture, and use a gauge to confirm that the overall height meets the requirements;

[0018] Step 4: Perform continuous cladding welding under argon back pressure, pay attention to controlling heat input and deformation, check the weld area after welding, and grind or calibrate it if necessary;

[0019] Step 5: Perform stress relief heat treatment to avoid cracks in the weld area due to stress concentration;

[0020] Step 6: Sandblast and clean the repaired parts and conduct penetration testing. If qualified, return to the normal repair process. Among them, the sandblasting parameters are set before penetration testing: medium aluminum oxide corundum, pressure 0.9 bar, distance 70 mm, and be careful not to continue to spray at a fixed point. Specific embodiment 2

[0022] A method for repairing flame tube over-temperature damage includes the following steps:

[0023] Step 1: Use an ultrasonic testing device to detect the thickness of the outlet ring and the cone, record the size value and mark the height that needs to be replaced; wherein the parameters of the ultrasonic testing device are set as follows: basic gain: 95dB, sound speed determined according to the component structure and the parent material: 4000m / s, compensation: 9dB;

[0024] Step 2: Use the same material as the flame tube body or an alternative material with equivalent performance to carry out cutting, rounding, resistance spot welding, brazing, discharge hole processing and necessary correction to prepare the outlet ring assembly; the parameters of the brazing heat treatment are set as follows: heating rate 38℃ / min, holding temperature 1290℃, cooling rate 14℃ / min; the setting parameters of the discharge hole processing are as follows: electrode diameter: 1.9mm, high pressure water pressure: 86kg / cm 2 , current: 8.2A, voltage: 23V;

[0025] Step 3: Refer to the thickness of the body, reserve welding gap, perform pre-welding cleaning, spot weld positioning and fix on the outlet ring welding fixture, and use a gauge to confirm that the overall height meets the requirements;

[0026] Step 4: Perform continuous cladding welding under argon back pressure, pay attention to controlling heat input and deformation, check the weld area after welding, and grind or calibrate it if necessary;

[0027] Step 5: Perform stress relief heat treatment to avoid cracks in the weld area due to stress concentration;

[0028] Step 6. Sandblast the repaired parts and conduct penetration testing. If qualified, return to the normal repair process. Among them, the sandblasting parameters are set before penetration testing: medium aluminum oxide corundum, pressure 0.7bar, distance 40mm, and be careful not to continue to spray at a fixed point. Specific embodiment three

[0030] A method for repairing flame tube over-temperature damage includes the following steps:

[0031] Step 1: Use an ultrasonic testing device to detect the thickness of the outlet ring and cone, record the size value and mark the height that needs to be replaced; wherein, the parameters of the ultrasonic testing device are set as follows: basic gain: 90-95dB, sound speed determined according to the component structure and parent material: 4600m / s, compensation: 11dB;

[0032] Step 2: Use the same material as the flame tube body or an alternative material with equivalent performance to carry out cutting, rounding, resistance spot welding, brazing, discharge hole processing and necessary correction to prepare the outlet ring assembly; the parameters of the brazing heat treatment are set as follows: heating rate 36℃ / min, maintaining temperature 1270℃, cooling rate 16℃ / min; the setting parameters of the discharge hole processing are as follows: electrode diameter: 1.7mm, high pressure water pressure: 85kg / cm 2 , current: 7.6A, voltage: 24V;

[0033] Step 3: Refer to the thickness of the body, reserve welding gap, perform pre-welding cleaning, spot weld positioning and fix on the outlet ring welding fixture, and use a gauge to confirm that the overall height meets the requirements;

[0034] Step 4: Perform continuous cladding welding under argon back pressure, pay attention to controlling heat input and deformation, check the weld area after welding, and grind or calibrate it if necessary;

[0035] Step 5: Perform stress relief heat treatment to avoid cracks in the weld area due to stress concentration;

[0036] Step 6: Sandblast and clean the repaired parts and conduct penetration testing. If qualified, return to the normal repair process. Among them, the sandblasting parameters are set before penetration testing: medium aluminum oxide corundum, pressure 0.8 bar, distance 60 mm, and be careful not to continue to spray at a fixed point.

[0037] The above is a preferred embodiment of the present invention, which cannot be used to limit the scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, modification or equivalent replacement of the technical solution of the present invention does not depart from the protection scope of the present invention.

Claims

1. A method for repairing flame tube overtemperature damage, characterized in that: The steps include: Step 1: Use an ultrasonic testing device to detect the thickness of the outlet ring and the cone, record the size value and mark the height that needs to be replaced; wherein the parameters of the ultrasonic testing device are set as follows: basic gain: 90-95dB, sound speed determined according to the component structure and parent material: 4000m / s-5000m / s, compensation: 9-13dB; Step 2: Use the same material as the flame tube body or an alternative material with equivalent performance to carry out cutting, rounding, resistance spot welding, brazing, discharge hole processing and necessary correction to prepare the outlet ring assembly; wherein the parameters of the brazing heat treatment are set as follows: heating rate 32-38℃ / min, holding temperature 1250-1290℃, cooling rate 14-19℃ / min; Step 3: Refer to the thickness of the body, reserve welding gap, perform pre-welding cleaning, spot weld positioning and fix on the outlet ring welding fixture, and use a gauge to confirm that the overall height meets the requirements; Step 4: Perform continuous cladding welding under argon back pressure, pay attention to controlling heat input and deformation, check the weld area after welding, and grind or calibrate it if necessary; Step 5: Perform stress relief heat treatment to avoid cracks in the weld area due to stress concentration; Step 6: Sandblast and clean the repaired parts and conduct penetration testing. If qualified, return to the normal repair process. Among them, the sandblasting parameters are set before penetration testing: medium aluminum oxide corundum, pressure 0.7-0.9bar, distance 40-70mm, and be careful not to continue to spray at a fixed point.

2. The method for repairing flame tube overheating damage according to claim 1, characterized in that: The setting parameters for discharge hole processing in step 2 are as follows: electrode diameter: 1.6-1.9 mm, high pressure water pressure: 83-86 kg / cm 2 , current: 6.8-8.2A, voltage: 23-26V.