GH4169 alloy bar forging method for protecting surface through coating

Abstract

The invention provides a GH4169 alloy bar forging method utilizing a coating to protect a surface, which comprises the following steps: 1) preserving heat in a temperature interval of 1040-1140 DEG C, setting the heat preservation time to be 1.5-12 hours according to the temperature when a material enters a furnace, performing at least three heating numbers of upsetting and drawing deformation on a cast ingot on a 8000T fast forging machine, controlling the upsetting deformation amount to be 15-50%, controlling the upsetting rate to be 10-20mm / s, and controlling the upsetting time to be 1.5-12 hours according to the temperature when the material enters the furnace; the drawing deformation is 18%-35%, and the drawing speed is 40mm / s-60mm / s; (2) heat preservation is conducted in the temperature interval of 980-1040 DEG C, the heat preservation time is set to be 2-10 h according to the temperature when the materials enter the furnace, drawing deformation of at least two heating numbers is conducted on a 8000 T fast forging machine, the deformation amount of drawing of each heating number ranges from 10% to 35%, the drawing speed ranges from 40 mm / s to 60 mm / s, the drawn materials are shaped to phi 380-phi 480 mm, and the materials are cooled to the room temperature; the surface of the material is protected in a coating spraying mode, the problems that the temperature drop of the surface of the material is fast and the forging window interval is narrow in the current production forging process can be solved, and the mixed crystal condition of the surface structure of the material is prevented. Asbestos which easily causes pollution in production is replaced, and the generation of wastes is reduced.

Description

Technical Field

[0001] The invention belongs to the field of hot processing of metal materials, and in particular relates to a GH4169 alloy bar forging method utilizing a coating to protect the surface. Background Art

[0002] GH4169 alloy is a precipitation-strengthened nickel-based superalloy. Its yield strength in the temperature range of -253 to 650°C ranks first among deformable superalloys. It has excellent fatigue resistance, radiation resistance, and corrosion resistance. It is the most widely used deformable superalloy both domestically and internationally, with an annual output of over 20,000 tons, accounting for over 50% of the total output of deformable superalloys. GH4169 alloy has good deformation properties, but the material surface temperature drops rapidly during forging, and the forging window is narrow, which can easily lead to mixed crystals on the material surface. Existing production often uses asbestos to coat the material to slow the temperature drop, but this produces a large amount of waste.

[0003] The present invention provides a GH4169 alloy bar forging method using a coating to protect the surface, which can be used to solve the problem of mixed crystals on the surface of the material that is easily seen in the existing forging technology and reduce pollution. Summary of the Invention

[0004] The object of the present invention is to provide a GH4169 alloy bar forging method using a coating to protect the surface, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for forging GH4169 alloy bars using a coating to protect the surface, comprising the following steps:

[0006] Step 1, keeping the temperature within the range of 1040°C to 1140°C, setting the holding time to 1.5h to 12h according to the temperature of the material when entering the furnace, and subjecting the ingot to at least three fires of upsetting and drawing deformation on an 8000T fast forging machine, with the upsetting deformation amount being 15% to 50% and the upsetting rate being 10mm / s to 20mm / s, and the drawing deformation amount being 18% to 35% and the drawing rate being 40mm / s to 60mm / s;

[0007] Step 1, heat preservation in the temperature range of 980℃~1040℃, set the heat preservation time for 2h~10h according to the temperature of the material when entering the furnace, perform at least 2 fires of drawing deformation on an 8000T fast forging machine, the deformation amount of each fire is 10%~35%, the drawing rate is 40mm / s~60mm / s, after drawing, the material is shaped to Ф380~Ф480mm, and the material is cooled to room temperature;

[0008] Step 3: Spray or brush a certain type of thermal insulation coating on the surface, spray at least twice, and the coating thickness must be ≥0.3mm;

[0009] Step 4: Maintain the temperature within a range of 980°C to 1040°C, set the holding time to 2h to 10h according to the temperature of the material when it enters the furnace, perform at least two rounds of drawing deformation on an 8000T high-speed forging machine, with the deformation amount of each drawing being 5% to 35% and the drawing rate being 40mm / s to 60mm / s. After forging, the material is air-cooled.

[0010] Preferably, the ingot in step 1 is a GH4169 alloy ingot, which is smelted by a triple melting process of vacuum induction melting, protective atmosphere electroslag remelting, and vacuum consumable melting. The ingot diameter is 420 mm to 550 mm, and its chemical composition is as follows: carbon ≤ 0.06%, chromium 17.00% to 21.00%, nickel 50.00% to 55.00%, cobalt ≤ 1.0%, molybdenum 2.80% to 3.30%, aluminum 0.30% to 0.70%, titanium 0.75% to 1.15%, niobium 5.00% to 5.50%, boron ≤ 0.006%, magnesium ≤ 0.005%, manganese ≤ 0.35%, silicon ≤ 0.35%, sulfur ≤ 0.002%, phosphorus ≤ 0.015%, copper ≤ 0.30%, tantalum ≤ 0.10%, calcium ≤ 0.005%, oxygen ≤ 0.005%, nitrogen ≤ 0.01%, and the rest is iron.

[0011] Preferably, during the forging process described in steps 1, 2 and 4, the upsetting rate is 10 mm / s to 20 mm / s, the drawing rate is 40 mm / s to 60 mm / s, and the drawing is performed in a radial direction.

[0012] Preferably, the coating used in step 3 needs to be dried or air-dried between each spraying or brushing, and the coating needs to cover the surface of the material evenly and flatly.

[0013] Compared with existing technologies, the present invention offers the following advantages: It utilizes a spray coating to protect the material surface, remedying the current problems of rapid surface temperature drop and a narrow forging window during forging, preventing the formation of mixed crystals on the material surface. It also replaces asbestos, a material that is prone to pollution during production, and reduces waste generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a photo of the material surface after spraying the coating;

[0015] Figure 2 It is the finished product structure of the material after forging. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1-Figure 2 The present invention provides a technical solution: a GH4169 alloy bar forging method using a coating to protect the surface, specifically comprising the following steps:

[0018] Step 1: Maintaining the temperature within a range of 1040° C. to 1140° C., setting the holding time to 1.5 to 12 hours according to the temperature of the material when entering the furnace, subjecting the ingot to at least three rounds of upsetting and drawing deformation on an 8000T high-speed forging machine, with the upsetting deformation amount being 15% to 50% at an upsetting rate of 10 mm / s to 20 mm / s, and the drawing deformation amount being 18% to 35% at a drawing rate of 40 mm / s to 60 mm / s;

[0019] Step 2: Maintain the temperature within a range of 980°C to 1040°C, set the holding time to 2h to 10h according to the temperature of the material when it enters the furnace, perform at least two drawing cycles on an 8000T high-speed forging machine, with the deformation amount of each drawing cycle being 10% to 35% and the drawing rate being 40mm / s to 60mm / s. After drawing, the material is shaped to Ø380 to Ø480mm, and the material is cooled to room temperature.

[0020] Step 3: Spray or brush a certain type of thermal insulation coating on the surface, spray at least twice, and the coating thickness must be ≥ 0.3mm;

[0021] Step 4: Keep the temperature within the range of 980°C to 1040°C, set the holding time to 2h to 10h according to the temperature of the material when it enters the furnace, perform at least two rounds of drawing deformation on an 8000T fast forging machine, the deformation amount of each drawing is 5% to 35%, the drawing rate is 40mm / s to 60mm / s, and the material is air-cooled after forging.

[0022] Example 1

[0023] A method for forging a GH4169 alloy bar using a coating to protect the surface comprises the following steps:

[0024] Step 1: Forging the GH4169 alloy ingot at 1110° C., keeping the temperature for 3 to 10 hours, and performing upsetting and drawing deformation for 3 times, with the upsetting deformation amount being 25% and the drawing deformation amount being 33%.

[0025] Step 2: Keep the blank at 1030° C. for 2 to 8 hours, draw it for 3 times, and draw it with a deformation of 25%, and then cool it.

[0026] Step 3: Spray or brush the thermal insulation coating on the surface of the material, spray at least twice, and the coating thickness must be ≥0.3mm;

[0027] Step 4: Keep the temperature at 1000°C for 2 hours to 10 hours, draw the steel for 2 times, and draw the steel with a deformation of 5% to 25%. After forging, the steel is air-cooled.

[0028] Example 2

[0029] A method for forging a GH4169 alloy bar using a coating to protect the surface comprises the following steps:

[0030] Step 1: Forging the GH4169 alloy ingot at 1110° C., keeping the temperature for 3 to 10 hours, and performing upsetting and drawing deformation for 3 times, with the upsetting deformation amount being 25% and the drawing deformation amount being 33%.

[0031] Step 2: Keep the blank at 1020° C. for 2 to 9 hours, draw it for 3 times, and draw the deformation by 28%, and then cool the material.

[0032] Step 3: Spray or brush the thermal insulation coating on the surface of the material, spray at least twice, and the coating thickness must be ≥0.3mm;

[0033] Step 4: Keep the temperature at 1005°C for 2 hours to 10 hours, draw the steel piece for 2 times, and draw the steel piece with a deformation of 5% to 20%. After forging, the steel piece is air-cooled.

[0034] Example 3

[0035] A method for forging a GH4169 alloy bar using a coating to protect the surface comprises the following steps:

[0036] Step 1: Forging the GH4169 alloy ingot at 1100° C., keeping the temperature for 3 to 10 hours, and performing upsetting and drawing deformation for 3 times, with the upsetting deformation amount being 25% and the drawing deformation amount being 30%.

[0037] Step 2: Keep the blank at 1030° C. for 2 to 8 hours, draw it for 3 times, and draw it with a deformation of 25%, and then cool it.

[0038] Step 3: Spray or brush the thermal insulation coating on the surface of the material, spray at least twice, and the coating thickness must be ≥0.3mm;

[0039] Step 4: Keep the temperature at 1000°C for 2 hours to 10 hours, draw the steel for 2 times, and draw the steel with a deformation of 5% to 25%. After forging, the steel is air-cooled.

[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for forging GH4169 alloy bars using a coating to protect the surface, characterized in that: The following steps are involved: Step 1, keeping the temperature within the range of 1040°C to 1140°C, setting the holding time to 1.5h to 12h according to the temperature of the material when entering the furnace, and subjecting the ingot to at least three fires of upsetting and drawing deformation on an 8000T fast forging machine, with the upsetting deformation amount being 15% to 50% and the upsetting rate being 10mm / s to 20mm / s, and the drawing deformation amount being 18% to 35% and the drawing rate being 40mm / s to 60mm / s; Step 2, keeping the temperature within the range of 980°C to 1040°C, setting the holding time to 2h to 10h according to the temperature of the material when entering the furnace, performing at least two rounds of drawing deformation on an 8000T fast forging machine, with the deformation amount of each drawing being 10% to 35% and the drawing rate being 40mm / s to 60mm / s. After drawing, the material is shaped to Ø380 to Ø480mm, and the material is cooled to room temperature; Step 3: Spray or brush a certain type of thermal insulation coating on the surface, spray at least twice, and the coating thickness must be ≥0.3mm; Step 4: Maintain the temperature within a range of 980°C to 1040°C, set the holding time to 2h to 10h according to the temperature of the material when it enters the furnace, perform at least two rounds of drawing deformation on an 8000T high-speed forging machine, with the deformation amount of each drawing being 5% to 35% and the drawing rate being 40mm / s to 60mm / s. After forging, the material is air-cooled.

2. The method for forging GH4169 alloy bars using a coating to protect the surface according to claim 1, characterized in that: The ingot in step 1 is a GH4169 alloy ingot, which is smelted by a triple melting process of vacuum induction melting, protective atmosphere electroslag remelting, and vacuum consumable melting. The ingot diameter is 420 mm to 550 mm, and its chemical composition is as follows: carbon ≤ 0.06%, chromium 17.00% to 21.00%, nickel 50.00% to 55.00%, cobalt ≤ 1.0%, molybdenum 2.80% to 3.30%, aluminum 0.30% to 0.70%, titanium 0.75% to 1.15%, niobium 5.00% to 5.50%, boron ≤ 0.006%, magnesium ≤ 0.005%, manganese ≤ 0.35%, silicon ≤ 0.35%, sulfur ≤ 0.002%, phosphorus ≤ 0.015%, copper ≤ 0.30%, tantalum ≤ 0.10%, calcium ≤ 0.005%, oxygen ≤ 0.005%, nitrogen ≤ 0.01%, and the rest is iron.

3. The method for forging GH4169 alloy bars using a coating to protect the surface according to claim 1, characterized in that: During the forging process of step 1, step 2 and step 4, the upsetting rate is 10 mm / s to 20 mm / s, the drawing rate is 40 mm / s to 60 mm / s, and the drawing is performed in radial direction.

4. The method for forging GH4169 alloy bars using a coating to protect the surface according to claim 1, characterized in that: The coating used in step 3 needs to be dried or air-dried between each spraying or brushing, and the coating needs to be evenly and evenly covered on the surface of the material.

Images