Welding method for GH4163 with thickness of 12 mm

Abstract

The invention provides a welding method for GH4163 with the thickness of 12 mm. The welding method comprises the following steps that S1, the welding seam form is determined; s2, welding seam groove machining; s3, pre-welding pretreatment and material preparation are conducted; s4, welding is conducted; s5, backing welding and filling welding are carried out; s6, postweld heat treatment; and S7, inspection is conducted after welding. The number of welding layers is reduced through the U-shaped groove coloring agent, and heat input is reduced; gH4163 is adopted to improve the toughness of the welding seam and inhibit Laves phase precipitation; and interlayer temperature and postweld heat treatment parameters are accurately controlled, welding stress is effectively released, and uniform precipitation of a strengthening phase is promoted. And a final welding joint has no defects such as cracks, is high in strength and excellent in toughness, and can meet the strict service requirements of thick-wall GH4163 components.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature alloy welding technology, specifically relating to a welding method for 12mm thick GH4163 alloy. Background Technology

[0002] GH4163 is a precipitation-hardening nickel-based superalloy with excellent high-temperature strength, corrosion resistance, and fatigue resistance. It exhibits stable performance during long-term service below 650℃ and is widely used in aerospace, energy, and chemical industries. However, GH4163 alloy contains elements such as Nb and Ti. During welding, Nb segregation can easily lead to the formation of the Laves phase, increasing the weld's susceptibility to hot cracking. Furthermore, welding 12mm thick plates requires multiple layers and passes, resulting in a large cumulative heat input and significant welding stress, which weakens the joint performance and makes it difficult to meet the requirements for high-temperature applications.

[0003] In existing technologies, welding of GH4163 alloy mainly focuses on thin plates (≤8mm), using single welding parameters or simplified heat treatment processes, which is difficult to adapt to the welding requirements of 12mm thick plates. Some processes fail to control the interpass temperature, resulting in uneven weld metal microstructure; some process failure handling parameters are unreasonable, failing to fully precipitate the strengthening phase, resulting in insufficient joint strength. Summary of the Invention

[0004] The purpose of this invention is to provide a welding method for 12mm thick GH4163.

[0005] A welding method for 12mm thick GH4163 includes the following steps: S1, determine the weld type; S2, weld beveling; S3, Pre-welding treatment and material preparation; S4, welding; S5, root pass and fill pass welding; S6, post-weld heat treatment; S7, Post-weld inspection.

[0006] Furthermore, in S1, the weld seam is a single-sided bevel with double-sided forming, and the bevel is a U-shaped bevel.

[0007] Furthermore, in S2, the weld bevel is made of 12mm thick GH4163 plate, and a U-shaped symmetrical bevel is machined using a CNC milling machine. The bevel angle is 15°, the blunt edge thickness is 2.0mm, the root gap is 1.5mm, and the root radius is 3mm.

[0008] Furthermore, in S3, the pre-welding pretreatment involves wiping the bevel and a 30mm area on both sides with acetone to remove surface oil; placing the plate in a resistance furnace, heating it to 150-200℃ at 5℃ / min, and holding it at that temperature for 35min to complete the preheating; and using GH4163 welding wire with a diameter of 1.2mm.

[0009] Furthermore, the S4 uses a TIG automatic welding equipment, with the shielding gas being Ar gas with a purity of 99.99%, the front argon shielding flow rate being 15-20 L / min, and the back argon shielding flow rate being 12-15 L / min; welding is performed in 9 layers.

[0010] Furthermore, in S5, the root pass welding is performed as follows: the preheated plate is taken out, fixed on the workbench, and the argon shielding device is installed. The welding current is 150-170A and the speed is 80-100mm / min. The fill pass welding current is 180-200A and the speed is 110-130mm / min. The interpass temperature is detected by an infrared thermometer and maintained at around 180℃.

[0011] Furthermore, after welding in step S6, the temperature is slowly cooled to room temperature, followed by solution treatment: the temperature is increased to 960°C at 6°C / min, held for 1.8 hours, and then air-cooled; then aging treatment is performed: the temperature is increased to 730°C at 4°C / min, held for 9 hours, and then furnace-cooled to 450°C before air-cooling.

[0012] Furthermore, in S7, the weld appearance is smooth after welding, with an excess height of 2-3mm; penetrant testing shows no surface defects; radiographic testing meets the requirements of Q / 703J 132 Class I; the tensile strength is 920MPa, and the high-temperature tensile strength at 650℃ is 765MPa, which meets the usage requirements.

[0013] Furthermore, the overlap between the 9-layer multi-pass welding layers is 1 / 2 of the welding wire diameter, and the welding directions of adjacent weld passes are opposite to offset welding stress.

[0014] Furthermore, after the solution treatment, the grain size of the weldment is controlled at level 5-7, and after the aging treatment, a uniform γ-reinforcing phase is precipitated, with a volume fraction of not less than 15%.

[0015] The beneficial effects of this invention are as follows: It reduces the number of welding layers and lowers heat input by using a U-shaped groove colorant; it improves weld toughness and inhibits Laves phase precipitation by employing GH4163; and it precisely controls interpass temperature and post-weld heat treatment parameters to effectively release welding stress and promote uniform precipitation of strengthening phases. The final welded joint is free of cracks and other defects, exhibiting excellent high strength and toughness, meeting the stringent service requirements of thick-walled GH4163 components. Attached Figure Description

[0016] Figure 1A schematic diagram of the 12mm thick plate structure provided by the present invention. In the diagram: 1. Weld seam; 2. Base material of the weldment. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings.

[0018] like Figure 1 As shown, a welding method for 12mm thick GH4163 includes the following steps: S1, Determine the weld type; the weld type is a single-sided bevel with double-sided forming, and the bevel type adopts a U-shaped bevel. S2, Weld beveling; Select 12mm thick GH4163 plate and use CNC milling machine to process U-shaped symmetrical beveling, beveling angle 15°, blunt edge thickness 2.0mm, root gap 1.5mm, root radius 3mm.

[0019] S3, Pre-welding treatment and material preparation; Wipe the bevel and a 30mm radius on both sides with acetone to remove surface oil; place the plate in a resistance furnace and heat it to 150-200℃ at a rate of 5℃ / min, hold for 35 minutes to complete preheating; use GH4163 welding wire with a diameter of 1.2mm.

[0020] S4, welding; The TIG automatic welding equipment was used, with the shielding gas being Ar gas with a purity of 99.99%. The argon gas flow rate for the front side was 15-20 L / min, and the argon gas flow rate for the back side was 12-15 L / min. The welding was carried out in 9 layers.

[0021] S5, root pass and fill pass welding; Take out the preheated plate, fix it on the workbench, and assemble the back argon protection device. Welding current: 150-170A, speed: 80-100mm / min; Fill welding current: 180-200A, speed: 110-130mm / min; Interpass temperature is detected by infrared thermometer and kept at around 180℃.

[0022] S6, post-weld heat treatment; After welding, the sample is slowly cooled to room temperature and then subjected to solution treatment: the temperature is increased to 960℃ at 6℃ / min, held for 1.8 hours, and then air-cooled; then aging treatment is performed: the temperature is increased to 730℃ at 4℃ / min, held for 9 hours, and then furnace-cooled to 450℃ before air-cooling.

[0023] S7, Post-welding inspection; The weld has a smooth appearance with a reinforcement height of 2-3mm; penetrant testing shows no surface defects; radiographic testing meets the requirements of Q / 703J 132 Class I; tensile strength is 920MPa, and high-temperature tensile strength at 650℃ is 765MPa, which meets the usage requirements.

[0024] Table 1 Welding Parameters

[0025] Table 2 Welding Dimension Data Interpass temperature monitoring during welding:

Claims

1. A welding method for 12mm thick GH4163, characterized in that, Includes the following steps: S1, determine the weld type; S2, weld beveling; S3, Pre-welding treatment and material preparation; S4, welding; S5, root pass and fill pass welding; S6, post-weld heat treatment; S7, Post-weld inspection.

2. The welding method for 12mm thick GH4163 according to claim 1, characterized in that, The weld in S1 is a single-sided bevel with double-sided forming, and the bevel is a U-shaped bevel.

3. The welding method for 12mm thick GH4163 according to claim 1, characterized in that, The weld bevel processing in S2 uses 12mm thick GH4163 plate, and a U-shaped symmetrical bevel is processed by CNC milling machine. The bevel angle is 15°, the blunt edge thickness is 2.0mm, the root gap is 1.5mm, and the root radius is 3mm.

4. The welding method for 12mm thick GH4163 according to claim 1, characterized in that, In step S3, the pre-welding treatment involves wiping the bevel and a 30mm area on both sides with acetone to remove surface oil. The plate is then placed in a resistance furnace and heated to 150-200℃ at a rate of 5℃ / min, and held for 35 minutes to complete the preheating. GH4163 welding wire with a diameter of 1.2mm is selected.

5. The welding method for 12mm thick GH4163 according to claim 1, characterized in that, The S4 section uses a TIG automatic welding equipment with Ar gas of 99.99% purity as the shielding gas. The argon gas flow rate for the front side is 15-20 L / min, and the argon gas flow rate for the back side is 12-15 L / min. The welding is performed in 9 layers.

6. The welding method for 12mm thick GH4163 according to claim 1, characterized in that, In the S5 root pass welding: take out the preheated plate, fix the plate on the workbench, and assemble the back argon protection device. The welding current is 150-170A and the speed is 80-100mm / min. The fill pass welding current is 180-200A and the speed is 110-130mm / min. The interpass temperature is detected by an infrared thermometer and kept at around 180℃.

7. The welding method for 12mm thick GH4163 according to claim 1, characterized in that, After welding in S6, the temperature is slowly cooled to room temperature, followed by solution treatment: the temperature is increased to 960°C at 6°C / min, held for 1.8 hours, and then air-cooled; then aging treatment is performed: the temperature is increased to 730°C at 4°C / min, held for 9 hours, and then furnace-cooled to 450°C before air-cooling.

8. A welding method for 12mm thick GH4163 according to claim 1, characterized in that, The weld in S7 is inspected after welding and found to be smooth with a weld reinforcement of 2-3mm; penetrant testing shows no surface defects; radiographic testing meets the requirements of Q / 703J 132 Class I; tensile strength is 920MPa, and high-temperature tensile strength at 650℃ is 765MPa, which meets the usage requirements.

9. A welding method for 12mm thick GH4163 according to claim 5, characterized in that, The overlap between the 9-layer, multi-pass welding layers is 1 / 2 of the welding wire diameter, and the welding directions of adjacent weld passes are opposite to offset welding stress.

10. A welding method for 12mm thick GH4163 according to claim 7, characterized in that, After the solution treatment, the grain size of the weldment is controlled at level 5-7. After the aging treatment, a uniform γ-strengthening phase is precipitated, and the volume fraction of the strengthening phase is not less than 15%.

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