GH4169 high-temperature alloy seamless tube and production process thereof

Abstract

The invention belongs to the field of metal material machining, and discloses a GH4169 high-temperature alloy seamless tube and a production process thereof, and the GH4169 high-temperature alloy seamless tube is obtained through the steps of smelting, hollow ingot rough machining, hollow ingot solution treatment, blank finish machining, blank flaw detection, blank heating, pierced billet extrusion, pierced billet solution treatment, cold rolling and final cold rolled tube solution treatment. The tensile strength Rm of the seamless tube is larger than or equal to 635 MPa, the yield strength Rp0.2 is larger than or equal to 245 MPa, the percentage elongation after fracture A% is larger than or equal to 30%, the grain size is smaller than 4.0 level, and the intergranular corrosion rate in 65% boiling nitric acid is smaller than or equal to 1.2 mm / year. The production technology is low in energy consumption, high in material utilization rate, short in production process flow and short in machining period, and the finished pipe is high in size precision, few in pipe layering and cracks and suitable for machining of seamless pipes in the metal material machining industry.

Description

Technical Field

[0001] The invention belongs to the field of metal material processing, in particular to a GH4169 high-temperature alloy seamless pipe and a production process thereof. Background Art

[0002] GH4169 high-temperature alloy is a precipitation-hardened deformation alloy. Its main components include iron, chromium, nickel, niobium, aluminum and titanium. It has a high alloy content and its structure consists of matrix γ phase, δ phase, niobium carbide, titanium nitride, γ″ phase, γ' phase and Laves phase. It has high strength, good fatigue resistance and corrosion resistance at -253~650℃, and its instantaneous operating temperature reaches 800℃. It is widely used in aviation, aerospace, nuclear energy and petrochemical industries.

[0003] In the prior art, the main forming methods of seamless pipes are hot perforation and hot extrusion. In the hot perforation process, the cross-section of the rolled piece is a process from circle to ellipse and then to circle, and the metal on each circumferential surface is constantly subjected to alternating stress. GH4169 high-temperature alloy has large deformation resistance, poor plasticity, and a narrow window of hot working process parameters. After perforation, serious cracks and folds will appear on the surface, resulting in the scrapping of the material. Therefore, the conventional production process route of GH4169 high-temperature alloy seamless pipe is: induction melting + electroslag remelting + solid billet forging + billet drilling + hot hole expansion + flat die extrusion + rough pipe solid solution + cold rolling and cold drawing + finished product solid solution.

[0004] Problems with the above process:

[0005] 1. Forging of solid billets increases energy consumption;

[0006] Second, drilling a thick-walled hollow tube into a billet will result in a large amount of metal waste;

[0007] 3. After hot expansion, hot extrusion of seamless rough pipes not only has a long production process, but also has a very low material utilization rate, high cost and long processing cycle;

[0008] 4. When a flat die is used for extrusion, the metal flow resistance is large, delamination and cracks are prone to occur, and the extrusion pressure is high. Summary of the invention

[0009] In order to solve the above deficiencies in the prior art, the present invention aims to provide a GH4169 high-temperature alloy seamless pipe and its production process, so as to avoid material waste, shorten the process flow, reduce energy consumption, improve material utilization, reduce production costs, and avoid delamination and cracks of the pipe.

[0010] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a GH4169 high-temperature alloy seamless pipe, wherein the components of the seamless pipe include, by mass percentage, C: 0.01-0.07, S: ≤0.012, Si: ≤0.40, P: ≤0.015, Mn: ≤0.45, Mo: 2.8-3.3, Cr: 17-21, Nb: 4.75-5.50, Ni: 50.5-55.0, Cu: ≤0.30, Al: 0.25-0.80, Co: 0.15-0.95, Ti: 0.65-1.15, B: ≤0.006, Mg: ≤0.10, W: ≤0.25, and the rest are Fe and unavoidable impurities.

[0011] As a limitation of the present invention: the outer diameter of the seamless pipe is in the range of 19 to 219 mm, the wall thickness is in the range of 1.5 to 25 mm, and the inner diameter is greater than 15 mm.

[0012] As a limitation of the present invention: the properties of the seamless pipe are: tensile strength Rm≥635MPa, yield strength Rp0.2≥245MPa, elongation after fracture A%≥30%, grain finer than grade 4.0, and intergranular corrosion rate in 65% boiling nitric acid≤1.2mm / year.

[0013] The present invention also discloses a production process of a GH4169 high temperature alloy seamless pipe, which is used to produce the above-mentioned GH4169 high temperature alloy seamless pipe, comprising the following steps:

[0014] S1: Smelting: vacuum induction melting is used to produce electrode blanks, and the electrode blanks are smelted into hollow ingots using electroslag remelting technology;

[0015] S2: Rough machining of hollow ingots; hollow ingots are machined to remove surface oxide scale and flatten the end faces at both ends;

[0016] S3: hollow ingot solution treatment;

[0017] S4: Finishing of the billet: Finishing the hollow ingot after solution treatment, drilling the inner hole with a deviation of ±0.5mm; turning the outer circle and polishing, the outer diameter deviation of the finished product is ±1mm; flattening the ends, the verticality of the end face is ≤1mm; machining the bevel at the outer circle of the head, and the bevel and the ingot body are rounded, the inner and outer surfaces are ground and polished, the surface roughness Ra≤1.6μm, the length deviation is ±5mm, the concentricity of the inner and outer circles is ≤1mm, and the billet is obtained;

[0018] S5: Billet flaw detection; non-destructive testing of billets;

[0019] S6: heating the blank; after preheating the blank, heating it twice, the first heating temperature is 1080℃~1100℃, the second heating temperature is 1120℃~1145℃, and then it is taken out of the furnace;

[0020] S7: extruding a rough pipe; extruding the heated billet into a rough pipe in a horizontal extruder, using a double cone die, and the extrusion ratio of the rough pipe is 4.0 to 11.0. The extruded rough pipe is water-cooled and then drained to dry;

[0021] S8: Solution treatment of the rough pipe: Use a continuous roller hearth furnace to heat the rough pipe to temperature in stages, and then water cool it;

[0022] S9: Cold rolling; the rough pipe after solution treatment is subjected to two to six passes of cold rolling by a periodic cold rolling mill, with a deformation of 30% to 55% in each pass, a feed of 3.0 to 5.0 mm / time, a rolling speed of 30 to 60 times / minute, and the cold rolling deformation of the last pass is controlled at 42% to 52% to obtain the final cold rolled pipe; the intermediate pipe after each cold rolling is firstly subjected to the removal of cold rolling oil in the degreasing tank, and then subjected to the solution treatment of the intermediate pipe, and then transported to the mixed acid pickling tank for pickling and descaling;

[0023] S10: Solution treatment of the final cold-rolled tube; the cold-rolled tube with an inner diameter of more than 35 mm is heated to temperature in a continuous roller hearth furnace and then water-cooled, and the cold-rolled tube with an inner diameter of 35 mm and below is heat-treated in a protective atmosphere bright furnace annealing furnace; the finished tube is obtained.

[0024] As a limitation of the present invention, step S3 specifically comprises: heating the roughly processed hollow ingot to 1120° C. to 1155° C., keeping the temperature for 2 min to 4 min / mm, putting the ingot into water, and cooling the ingot to below 30° C.

[0025] As a limitation of the present invention: in step S4, the bevel angle α at the outer circle of the billet head is 34°, and the fillet radius R at the connection between the bevel and the ingot body is 25 mm.

[0026] As a limitation of the present invention: Step S6 comprises,

[0027] S61: Preheating: put into the furnace when the temperature of the electric furnace is 800℃, heat up at a rate of 100℃ / h to 900℃, and keep warm for 2.5h to 4.5h;

[0028] S62: First heating: After preheating, the blank is transferred to an electromagnetic induction heating furnace for heating, with a heating power of 400KW to 500KW, a frequency of 38 to 58HZ, a temperature of 1080°C to 1100°C, and a soaking time of 1.5 to 4.5 minutes;

[0029] S63: second heating; heating power 550KW ~ 750KW, frequency 60 ~ 100HZ, temperature to 1120℃ ~ 1145℃, out of the furnace.

[0030] As a limitation of the present invention: Step S7 specifically includes:

[0031] S71: The inner wall of the extrusion barrel is heated to 200°C to 400°C, and the extrusion die and the core rod are heated to 250°C to 350°C;

[0032] S72: Graphite lubricating coating is evenly applied on the inner wall of the extrusion cylinder and the surface of the core rod;

[0033] S73: Apply glass powder on the inner and outer surfaces of the blank, and then transfer it to an extrusion cylinder. The inner diameter of the extrusion cylinder is 3.5 mm to 8.5 mm larger than the outer diameter of the blank, and a glass pad is placed at the entrance of the extrusion die;

[0034] S74: heating the tail pad prepared in advance to 780°C to 1000°C, and then attaching it to the tail of the billet, and the tail pad is extruded together with the billet;

[0035] S75: The power system of the extruder enables the extrusion rod to push the billet to move in the extrusion direction, and the billet advances at a speed of 50 mm / s to 200 mm / s to extrude the rough pipe;

[0036] S76: Put the extruded rough pipe into water at a temperature above 900°C and cool it to below 50°C, then take it out of the water and dry it.

[0037] As a limitation of the present invention: Step S8 is specifically as follows: the heating temperature of the first stage is 950°C, and the heating time is 1.0min~1.5min / mm; the heating temperature of the second stage is 980°C, and the heating time is 1.5min~2.0min / mm; the heating temperature of the third stage is 1020°C, and the heating time is 2.5min~6.0min / mm, and water is used as the cooling medium to achieve rapid cooling.

[0038] As a limitation of the present invention: in step S10, the specific processing technology of the cold-rolled tube with an inner diameter of more than 35 mm is: heating temperature 960°C ~ 990°C, heating time 3.0min ~ 7.0min / mm, using water as a cooling medium to achieve rapid cooling; the specific processing technology of the cold-rolled tube with an inner diameter of 35 mm and below is: heating temperature 960°C ~ 990°C, heating time 3.0min ~ 7.0min / mm, strong convection jet of protective gas + water cooling jacket cooling.

[0039] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0040] The invention adopts a process route combining optimized composition + hollow electroslag ingot + hot extrusion + cold rolling to produce GH4169 high-temperature alloy seamless pipes. The hollow electroslag ingot has a more dense and uniform structure and high purity, eliminating the traditional process of billet forging and hot hole expansion, avoiding a large amount of material waste caused by traditional solid ingot drilling, which not only shortens the production process and reduces energy consumption, but also improves material utilization, improves circulation efficiency, and reduces costs. Double cone dies are used during extrusion. Compared with flat dies, the metal flow resistance is reduced, the extrusion force is reduced, the deformation is smooth and uniform, and the stratification and cracking of the pipe are reduced.

[0041] The GH4169 high-temperature alloy seamless pipe produced by the present invention has high dimensional accuracy, uniform and fine microstructure, and performance consistent with that of the seamless pipe produced by using traditional solid forged electroslag billet as raw material, and has good corrosion resistance.

[0042] In summary, the production process of the present invention has low energy consumption, high material utilization rate, short production process flow and short processing cycle. The finished pipe of the present invention has high dimensional accuracy, few pipe delaminations and cracks, and is suitable for the processing of seamless pipes in the metal material processing industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Figure 1 A schematic diagram of a production process flow of an embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of the structure of the blank after fine processing in an embodiment of the present invention;

[0046] Figure 3 It is a structural schematic diagram of a horizontal extruder in the rough pipe extrusion stage in an embodiment of the present invention;

[0047] Figure 4 It is a structural schematic diagram of a double cone mold in an embodiment of the present invention;

[0048] Figure 5 It is a structural schematic diagram of a mold base in an embodiment of the present invention;

[0049] Figure 6 Schematic diagram of the cold rolling process of the seamless pipe in an embodiment of the present invention.

[0050] In the figure: 1-die tailstock; 2-die middle seat; 3-die seat; 4-double cone mold; 5-die support; 6-extrusion cylinder; 7-core rod; 8-tail pad; 9-extrusion pad; 10-extrusion rod; 11-core rod force transmission rod; 12-blank; 13-rough pipe; 14-final cold-rolled pipe; 15-upper roller; 16-lower roller; 17-inner mold. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the GH4169 high temperature alloy seamless pipe and the production process of the GH4169 high temperature alloy seamless pipe described herein are preferred embodiments, which are only used to illustrate and explain the present invention and do not constitute a limitation to the present invention.

[0052] The directional terms or positional relationships such as "up", "down", "left" and "right" described in the present invention are based on the directional relationships in the drawings of the present invention specification and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the content protected by the present invention.

[0053] This embodiment discloses a GH4169 high temperature alloy seamless pipe, the specification of which is φ108 mm (diameter) × 8 mm (wall thickness); the composition thereof is shown in Table 1:

[0054] Table 1 Composition of GH4169 high temperature alloy finished seamless pipe (mass percentage)

[0055] element C Si Mn P S Cr Ni Mo Measured 0.03 0.13 0.16 0.01 0.003 19.23 52.03 2.96 element Ti Nb Al Co Cu B Mg W Measured 1.07 5.03 0.43 0.26 0.04 0.003 0.05 0.02

[0056] Remarks: The rest is Fe and unavoidable impurities.

[0057] This embodiment also discloses a production process of GH4169 high temperature alloy seamless pipe, which is used to produce the above GH4169 high temperature alloy seamless pipe. Figure 1 As shown, the specific steps include:

[0058] S1: smelting; vacuum induction melting is used to produce electrode blanks. The surface of the electrode blanks is processed and the oxidized iron scale is cleaned. The electrode blanks are smelted by electroslag remelting technology. The electroslag remelting slag system adopts CaF2, CaO, Al2O3, MgO and TiO2 five-element slag system with a content ratio of 70:10:10:5:5 (%); vacuum protection is used in the whole process of electroslag remelting to effectively prevent oxidation, and a hollow ingot is obtained. The specifications of the hollow ingot are φ257mm (diameter)×φ125mm (inner diameter)×680mm (length).

[0059] S2: Rough machining of hollow ingots: The hollow ingots are machined to remove the surface oxide scale, and the two ends are flat, with specifications of φ250mm (diameter) × φ132mm (inner diameter) × 650mm (length).

[0060] S3: Solution treatment of hollow ingots; the furnace temperature when the hollow ingots are put into the furnace is 850℃~950℃, the holding time is 2.5min~4.5min / mm, the roughly processed hollow ingots are heated to 1135℃ at a speed of 150℃~250℃ / h, quickly put into water, and cooled to below 30℃, so as to reduce harmful precipitated phases and achieve uniformity of organization.

[0061] S4: Finishing of the blank: Finishing of the hollow ingot after solution treatment, drilling inner hole deviation ±0.5mm; turning outer circle and polishing, outer diameter deviation of finished product ±1mm; flat ends, end face verticality ≤1mm; grinding and polishing of inner and outer surfaces, removing scratches, turning tool marks and other defects, surface roughness Ra ≤1.6μm, length deviation ±5mm, inner and outer circle concentricity ≤1mm, to obtain the blank. Figure 2 As shown, the outer circle of the head of the blank 12 is processed to have an angle α of 34°, and the connection between the bevel and the ingot body is processed to have a fillet radius R of 25mm. The specifications of the blank 12 are φ247mm (diameter) × φ136mm (inner diameter) × 640mm (length).

[0062] S5: Billet flaw detection; non-destructive testing of the billet.

[0063] S6: heating the blank; heating the blank twice after preheating, specifically including:

[0064] S61: Preheating: put into the furnace when the temperature of the electric furnace is 800℃, heat up at a rate of 100℃ / h to 900℃, and keep warm for 3.0;

[0065] S62: First heating: After preheating, the blank is transferred to an electromagnetic induction heating furnace for heating, with a heating power of 400KW to 500KW, a frequency of 38 to 58HZ, a temperature of 1080°C to 1100°C, and a soaking time of 1.5 to 4.5 minutes;

[0066] S63: second heating; heating power 550KW ~ 750KW, frequency 60 ~ 100HZ, temperature to 1120 ℃ ~ 1145 ℃, in this embodiment, the second heating temperature reaches 1140 ℃, and then out of the furnace.

[0067] S7: rough tube extrusion: the heated billet is extruded into a rough tube in a horizontal extruder.

[0068] like Figure 3As shown, the horizontal extruder in the rough pipe extrusion stage includes a die tail seat 1, a die center seat 2, a die seat 3, a double cone mold 4, a die support 5, an extrusion barrel 6, a core rod 7, a tail pad 8, an extrusion pad 9, an extrusion rod 10 and a core rod force transmission rod 11. The double cone mold 4 and the die support 5 are installed inside the die seat 3, and the die center seat 2 and the die tail seat 1 are arranged on the left side of the die support 5 in sequence. The die support 5, the die center seat 2 and the die tail seat 1 jointly support and fix the double cone mold 4. The right side of the die seat 3 is the extrusion barrel 6, the inside of the extrusion barrel 6 is the billet 12, the inside of the billet 12 is the core rod 7, and the right side of the billet 12 is arranged with the tail pad 8 and the extrusion pad 9 in sequence. The outer diameter of the tail pad 8 is the same as the outer diameter of the blank, the inner diameter of the tail pad 8 is 4mm to 6mm larger than the inner diameter of the blank, and the length of the tail pad 8 is 85mm to 150mm. The tail pad 8 can make all the blanks 12 of GH4169 squeezed into tubes, thereby improving the yield rate. At the same time, the tail pad 8 is made of carbon steel, which is convenient for sawing and reducing the consumption of saw blades. The right side of the extrusion pad 9 is the extrusion rod 10, which provides extrusion force under the action of the oil pressure system. The function of the extrusion pad 9 is to avoid direct contact between the extrusion rod 10 and the blank 12 and to transmit the extrusion force. A mandrel force transmission rod 11 is arranged inside the extrusion rod 10, and the mandrel force transmission rod 11 is connected to the mandrel 7 through a thread. The blank 12 passes through the cavity composed of the mandrel 7 and the double cone mold 4 and becomes a rough tube 13.

[0069] like Figure 4 As shown, the external conical surface angle γ' of the double cone mold 4 is 23.5°; the internal entrance of the double cone mold 4 is composed of two mold angles, the mold angle β is 130°, and the mold angle β' is 50°; the length of the sizing belt is 9mm~15mm, and the transition areas of different cross-sections adopt arc angle transition, the radius of the transition area between the mold angle β section and the mold angle β' section is 16mm, and the radius of the transition area between the mold angle β' section and the sizing belt is 10mm.

[0070] like Figure 5 As shown, a circular platform is arranged vertically outside the internal entrance of the mold base 3, and the minimum width L of the platform is 15 mm, which is used to fix the glass pad. The cone angle γ at the position where the double cone mold 4 is installed inside the mold base 3 is 23.5°, which is equal to the included angle γ' of the external cone surface of the double cone mold 4, so as to facilitate firm installation.

[0071] The steps of extruding the rough pipe specifically include:

[0072] S71: The inner wall of the extrusion barrel is heated to 200°C to 400°C, and the extrusion die and the core rod are heated to 250°C to 350°C;

[0073] S72: Graphite lubricating coating is evenly applied on the inner wall of the extrusion cylinder and the surface of the core rod;

[0074] S73: The inner and outer surfaces of the blank are coated with glass powder, which is composed of CaO, MgO, SiO2, TiO2, Al2O3, Na2O, K2O, and B2O3, with a particle size of 0.15mm to 0.35mm, a viscosity of 30pA·s to 70pA·s, and a coating thickness of 0.2mm to 0.5mm. After coating, the blank is transferred to an extrusion barrel with an inner diameter of 255mm and a length of 1500mm. A glass pad is placed at the entrance of the extrusion die; the inner diameter of the glass pad is 10mm to 25mm larger than the diameter of the rough tube, and the thickness of the glass pad is 15mm to 20mm;

[0075] S74: The tail pad prepared in advance is heated to 950°C, and then attached to the tail of the billet, and the tail pad is extruded together with the billet;

[0076] S75: The power system of the extruder makes the extrusion rod push the billet to move in the extrusion direction. The billet advances at a speed of 150 mm / s, the inner diameter of the extrusion die is 164.5 mm, and the core rod diameter is 126.5 mm. The extrusion ratio of the rough tube is 4.5.

[0077] S76: The extruded rough pipe is cooled in water at a temperature above 900°C to below 50°C and then taken out of the water to dry. The cold specifications of the rough pipe are φ161mm (diameter) × 18mm (wall thickness).

[0078] S8: Solution treatment of the rough pipe: Use a continuous roller hearth furnace to heat the rough pipe to temperature in stages, and then water cool it. Specifically, the heating temperature of the first stage is 950℃, and the heating time is 1.2min / mm; the heating temperature of the second stage is 980℃, and the heating time is 1.5min / mm; the heating temperature of the third stage is 1020℃, and the heating time is 3.0min / mm. Water is used as the cooling medium to achieve rapid cooling.

[0079] S9: Cold rolling: Use a periodic cold rolling mill to perform two-pass cold rolling on the rough pipe after solid solution treatment, such as Figure 6As shown, in the cold rolling stage, the cyclic cold rolling tube mill is provided with an upper rolling roller 15, a lower rolling roller 16 and an inner die 17, and the final cold rolled tube 14 is obtained after cold rolling. The deformation process is rough tube φ161mm (diameter) × 18mm (wall thickness) - cold rolled intermediate product tube φ133mm (diameter) × 12mm (wall thickness) - final cold rolled tube φ108mm (diameter) × 8mm (wall thickness); the first pass deformation amount is 44%, the second pass deformation amount is 45%, the feed amount is 3.5mm / time, and the rolling speed is 40 times / minute to obtain the final cold rolled tube. After each cold rolling, the intermediate pipe is firstly treated with cold rolling oil removed in the degreasing tank, and then the intermediate pipe is subjected to solution treatment, the heating temperature is 1000℃, the heating time is 2.5min~6.0min / mm, and then water is used as the cooling medium to achieve rapid cooling. After solution treatment, it is transferred to the mixed acid pickling tank for pickling to remove the oxide scale, wherein the concentration ratio of the mixed acid is HF: 3~6%; HNO3: 15~20%, and the rest is water, the temperature of the mixed acid solution is 35℃~80℃, and the pickling time is 30min~120min.

[0080] S10: Solution treatment of the final cold-rolled tube; the cold-rolled tube with an inner diameter of more than 35 mm is heated in a continuous roller hearth furnace, the heating temperature is 960℃~990℃, the heating time is 3.0min~7.0min / mm, and water is used as the cooling medium to achieve rapid cooling; the cold-rolled tube with an inner diameter of 35mm and below is heat treated in a protective atmosphere bright furnace annealing furnace, the heating temperature is 960℃~990℃, the heating time is 3.0min~7.0min / mm, and the protective gas strong convection jet + water cooling jacket cooling;

[0081] The final cold-rolled tube in this embodiment is heated in a continuous roller hearth furnace at a heating temperature of 960° C. for a heating time of 4 min / mm, and is rapidly cooled using water as a cooling medium to obtain a finished tube.

[0082] The finished pipes are inspected, and the inspection data are shown in Table 2:

[0083] Table 2 Performance of finished pipe

[0084]

[0085]

[0086] According to Table 2, the finished pipe in this embodiment has a tensile strength Rm≥635MPa, a yield strength Rp0.2≥245MPa, an elongation after fracture A%≥30%, an intergranular corrosion rate in 65% boiling nitric acid according to method D in GB / T15260 of ≤1.2mm / year, and a grain finer than grade 4.0.

Claims

1. A GH4169 high temperature alloy seamless pipe, characterized in that: The composition of the seamless pipe by mass percentage includes: C: 0.01~0.07, S: ≤0.012, Si: ≤0.40, P: ≤0.015, Mn: ≤0.45, Mo: 2.8~3.3, Cr: 17~21, Nb: 4.75~5.50, Ni: 50.5~55.0, Cu: ≤0.30, Al: 0.25~0.80, Co: 0.15~0.95, Ti: 0.65~1.15, B: ≤0.006, Mg: ≤0.10, W: ≤0.25, the rest are Fe and unavoidable impurities.

2. The GH4169 high temperature alloy seamless pipe according to claim 1, characterized in that: The outer diameter of the seamless pipe ranges from 19 to 219 mm, the wall thickness ranges from 1.5 to 25 mm, and the inner diameter is greater than 15 mm.

3. The GH4169 high temperature alloy seamless pipe according to claim 1 or 2, characterized in that: The properties of the seamless pipe are: tensile strength Rm≥635MPa, yield strength Rp0.2≥245MPa, elongation after fracture A%≥30%, grain finer than grade 4.0, and intergranular corrosion rate in 65% boiling nitric acid≤1.2mm / year.

4. A production process for GH4169 high temperature alloy seamless pipe, used for producing the GH4169 high temperature alloy seamless pipe as claimed in any one of claims 1 to 3, characterized in that: The following steps are included: S1: Smelting: vacuum induction melting is used to produce electrode blanks, and the electrode blanks are smelted into hollow ingots using electroslag remelting technology; S2: Rough machining of hollow ingots; hollow ingots are machined to remove surface oxide scale and flatten the end faces at both ends; S3: hollow ingot solution treatment; S4: Finishing of the billet: Finishing the hollow ingot after solution treatment, drilling the inner hole with a deviation of ±0.5mm; turning the outer circle and polishing, the outer diameter deviation of the finished product is ±1mm; flattening the ends, the verticality of the end face is ≤1mm; machining the bevel at the outer circle of the head, and the bevel and the ingot body are rounded, the inner and outer surfaces are ground and polished, the surface roughness Ra≤1.6μm, the length deviation is ±5mm, the concentricity of the inner and outer circles is ≤1mm, and the billet is obtained; S5: Billet flaw detection; non-destructive testing of billets; S6: heating the blank; after preheating the blank, heating it twice, the first heating temperature is 1080℃~1100℃, the second heating temperature is 1120℃~1145℃, and then it is taken out of the furnace; S7: extruding a rough pipe; extruding the heated billet into a rough pipe in a horizontal extruder, using a double cone die, and the extrusion ratio of the rough pipe is 4.0 to 11.

0. The extruded rough pipe is water-cooled and then drained to dry; S8: Solution treatment of the rough pipe: Use a continuous roller hearth furnace to heat the rough pipe to temperature in stages, and then water cool it; S9: Cold rolling; the rough pipe after solution treatment is cold rolled for two to six passes by a periodic cold rolling mill, with a deformation of 30% to 55% in each pass, a feed of 3.0 to 5.0 mm / time, a rolling speed of 30 to 60 times / minute, and the cold rolling deformation of the last pass is controlled at 42% to 52% to obtain the final cold rolled pipe; the intermediate pipe after each cold rolling is firstly degreased in a degreasing tank to remove the cold rolling oil, and then the intermediate pipe is solution treated, and then transported to a mixed acid pickling tank for pickling and descaling; S10: Solution treatment of the final cold-rolled tube; the cold-rolled tube with an inner diameter of more than 35 mm is heated to temperature in a continuous roller hearth furnace and then water-cooled, and the cold-rolled tube with an inner diameter of 35 mm and below is heat-treated in a protective atmosphere bright furnace annealing furnace; the finished tube is obtained.

5. The production process of GH4169 high temperature alloy seamless pipe according to claim 4, characterized in that: Step S3 is specifically as follows: heating the roughly processed hollow ingot to 1120° C. to 1155° C., keeping the temperature for 2 min to 4 min / mm, putting it into water, and cooling it to below 30° C.

6. The production process of GH4169 high temperature alloy seamless pipe according to claim 4, characterized in that: In step S4, the bevel angle α at the outer circle of the billet head is 34°, and the fillet radius R at the connection between the bevel and the ingot body is 25 mm.

7. The production process of GH4169 high temperature alloy seamless pipe according to claim 4, characterized in that: Step S6 comprises, S61: Preheating: put into the furnace when the temperature of the electric furnace is 800℃, heat up at a rate of 100℃ / h to 900℃, and keep warm for 2.5h to 4.5h; S62: First heating: After preheating, the blank is transferred to an electromagnetic induction heating furnace for heating, with a heating power of 400KW to 500KW, a frequency of 38 to 58HZ, a temperature of 1080°C to 1100°C, and a soaking time of 1.5 to 4.5 minutes; S63: second heating; heating power 550KW ~ 750KW, frequency 60 ~ 100HZ, temperature to 1120℃ ~ 1145℃, out of the furnace.

8. The production process of GH4169 high temperature alloy seamless pipe according to claim 4, characterized in that: Step S7 specifically includes: S71: The inner wall of the extrusion barrel is heated to 200°C to 400°C, and the extrusion die and the core rod are heated to 250°C to 350°C; S72: Graphite lubricating coating is evenly applied on the inner wall of the extrusion cylinder and the surface of the core rod; S73: Apply glass powder on the inner and outer surfaces of the blank, and then transfer it to an extrusion cylinder. The inner diameter of the extrusion cylinder is 3.5 mm to 8.5 mm larger than the outer diameter of the blank, and a glass pad is placed at the entrance of the extrusion die; S74: heating the tail pad prepared in advance to 780°C to 1000°C, and then attaching it to the tail of the billet, and the tail pad is extruded together with the billet; S75: The power system of the extruder enables the extrusion rod to push the billet to move in the extrusion direction, and the billet advances at a speed of 50 mm / s to 200 mm / s to extrude the rough pipe; S76: Put the extruded rough pipe into water at a temperature above 900°C and cool it to below 50°C, then take it out of the water and dry it.

9. The production process of GH4169 high temperature alloy seamless pipe according to claim 4, characterized in that: Step S8 is specifically as follows: the heating temperature of the first stage is 950°C, and the heating time is 1.0min~1.5min / mm; the heating temperature of the second stage is 980°C, and the heating time is 1.5min~2.0min / mm; the heating temperature of the third stage is 1020°C, and the heating time is 2.5min~6.0min / mm, and water is used as the cooling medium to achieve rapid cooling.

10. The production process of GH4169 high temperature alloy seamless pipe according to claim 4, characterized in that: In step S10, the specific processing technology of the cold-rolled tube with an inner diameter of more than 35 mm is: heating temperature 960°C ~ 990°C, heating time 3.0min ~ 7.0min / mm, and rapid cooling using water as a cooling medium; the specific processing technology of the cold-rolled tube with an inner diameter of 35 mm and below is: heating temperature 960°C ~ 990°C, heating time 3.0min ~ 7.0min / mm, strong convection jet of protective gas + water cooling jacket cooling.

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