Preparation method of 05Cr17Ni4Cu4Nb high strength and toughness forging for sealing ring

Abstract

The application belongs to the technical field of alloy forging preparation, and particularly relates to a 05Cr17Ni4Cu4Nb forging preparation method for high-strength and high-toughness sealing rings. The 05Cr17Ni4Cu4Nb forging preparation method for high-strength and high-toughness sealing rings improves the strength of the forging matrix, reduces the crack propagation ability of the material, improves the crack propagation work of the material, and improves the toughness of the forging matrix. The 05Cr17Ni4Cu4Nb forging preparation method for high-strength and high-toughness sealing rings has high operability, improves the high-strength and high-toughness of the 05Cr17Ni4Cu4Nb sealing ring forging after heat deformation, cooling and direct aging.

Description

Technical Field

[0001] This invention belongs to the field of alloy forging technology, specifically relating to a method for preparing a 05Cr17Ni4Cu4Nb forging for a high-strength and tough sealing ring. Background Technology

[0002] Sealing rings are one of the most important components in mechanical seals, largely determining their performance and lifespan. Achieving both high mechanical strength and good toughness in sealing ring forgings is a significant technical challenge in their manufacturing. 05Cr17Ni4Cu4Nb is a precipitation-hardening stainless steel composed of elements such as C, Cr, Cu, Nb, and Ni, widely used in mechanical seal components such as sealing rings.

[0003] Currently, although 05Cr17Ni4Cu4Nb sealing ring forgings can barely meet the usage requirements through conventional solution treatment and aging heat treatment, the pass rate is limited. There are technical problems with insufficient strength, toughness and rigidity of 05Cr17Ni4Cu4Nb sealing ring forgings after heat treatment, which affects the service life of mechanical seals.

[0004] Therefore, in order to improve the strength and toughness of forgings after heat treatment, it is necessary to formulate reasonable process methods and carry out precise control in actual production. Summary of the Invention

[0005] To address the technical problem of insufficient strength and toughness of existing high-strength and toughness 05Cr17Ni4Cu4Nb forgings after conventional heat treatment, this invention provides a method for preparing high-strength and toughness 05Cr17Ni4Cu4Nb forgings.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A method for preparing a high-strength and high-toughness 05Cr17Ni4Cu4Nb sealing ring forging includes the following steps:

[0008] Step 1, Preparation of sealing ring blank: First, pre-fabricate the ring blank. The size of the ring blank is reserved according to the subsequent forging ratio. Then, the ring forging is annealed. After annealing, the outer end face and inner and outer surfaces of the forged ring blank are rough machined.

[0009] Step 2, Deformation heat treatment: The annular blank from Step 1 is heated to 1000℃~1050℃, and then the annular forging hole expansion process is completed on a hydraulic press. After the hole expansion of the annular blank is completed, the surface temperature of the forged sealing ring is not lower than 730℃. The forged sealing ring is then subjected to oil cooling solution treatment, and after being oil cooled to room temperature, it is subjected to deep cryogenic treatment.

[0010] Step 3, Aging Treatment: After the deep cryogenic treatment in Step 2, the sealing ring forging is subjected to aging heat treatment, and the tempering cooling method is air cooling, which completes the heat treatment and obtains a high-strength and tough 05Cr17Ni4Cu4Nb sealing ring forging.

[0011] Furthermore, the material of the high-strength and tough 05Cr17Ni4Cu4Nb sealing ring forging is composed of the following mass fractions: C≤0.04%, Si≤0.50%, Mn≤1.0%, P≤0.015%, S≤0.004%, Ni 4.50%~5.00%, Cu3.00%~3.50%, Cr 15.00%~16.00%, Nb 0.15%~0.40%.

[0012] Furthermore, before prefabricating the ring-shaped billet, the billet needs to undergo steelmaking and electroslag remelting processes.

[0013] Furthermore, in step 1, the annealing temperature is 650℃~700℃.

[0014] Furthermore, in step 2, the forging blank should be turned over quickly and at a uniform speed during hole expansion. To prevent the blank temperature from dropping too quickly, the tooling and auxiliary tools such as the reaming lever should be preheated to 350℃±20℃. The hole expansion to the required size of the sealing ring forging should be completed in one forging. During this forging process, the deformation ratio should be controlled to be greater than 1.3.

[0015] Furthermore, in step 2, a mixture of liquid nitrogen and alcohol is used to perform cryogenic treatment on the sealing ring forging, with the cryogenic treatment temperature between -40℃ and -60℃.

[0016] Furthermore, in step 3, the aging heat treatment temperature is 480℃±10℃, and the aging holding time is 5h~8h.

[0017] Compared with the prior art, the advantages of this invention are as follows.

[0018] This invention strengthens forgings through hot deformation by introducing dislocations into the material, inducing grain boundary migration, increasing the multiplication reaction of low-energy special grain boundaries and the dispersion distribution of high-energy random grain boundaries, regulating the characteristic distribution of austenite grain boundaries, and improving the strength of the forging matrix. At the same time, during the hot deformation process, the grains break and refine, the grain boundary area increases, and the grain boundaries become more tortuous, reducing the crack propagation ability inside the material, improving the crack propagation energy of the material, and improving the toughness of the forging matrix.

[0019] This invention is highly operable. After the forging is hot-deformed, cooled, and directly aged, it improves the technical problem of the strength and toughness of the 05Cr17Ni4Cu4Nb sealing ring forging after heat treatment. Detailed Implementation

[0020] The following discloses some embodiments of the present invention. Those skilled in the art can appropriately modify the process parameters to achieve the desired results based on the content of this document. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of the present invention have been described through preferred embodiments. Those skilled in the art can obviously make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0021] A method for preparing a high-strength and high-toughness 05Cr17Ni4Cu4Nb sealing ring forging includes the following steps:

[0022] This explanation will take a sealing ring forging with dimensions of Ø750×Ø550×130 as an example.

[0023] Step 1: Preparation of sealing ring blank: Electroslag steel ingot with specifications of Ø500×2000 is used. The ingot is blanked to 230×230×540, and then the blank is roughened from 540 to 135, rolled, punched, and trimmed. According to the subsequent forging hole expansion ratio of about 1.35, the ring blank is forged, and its ring blank forging size is Ø600×Ø330×135. Then the ring forging is annealed at 650℃~700℃. After annealing, the forged ring blank is rough machined on the outer end face and inner and outer surfaces.

[0024] Step 2, Deformation Heat Treatment: The ring blank of 05Cr17Ni4Cu4Nb rough-machined for the sealing ring is heated to 1000℃~1050℃. Then, the ring forging hole expansion process is completed on a hydraulic press. During the hole expansion, the forging blank is turned over quickly and uniformly. The tooling and auxiliary tools used for hole expansion are preheated to 350℃±20℃. The hole is expanded to Ø750×Ø550×130 in one pass. The deformation ratio during the forging process is about 1.35, which is greater than the deformation ratio of 1.3. When the hole expansion of the ring is completed, the surface temperature of the sealing ring forging is about 735℃. The forged sealing ring forging is then oil-cooled for solution treatment. After being oil-cooled to room temperature, the sealing ring forging is subjected to deep cryogenic treatment with a mixture of liquid nitrogen and alcohol. The deep cryogenic treatment temperature is between -40℃ and -60℃.

[0025] Step 3, Aging Treatment: After cryogenic treatment, the sealing ring forging is subjected to aging heat treatment at 480℃±10℃ for 5h~8h. The tempering cooling method is air cooling, which completes the heat treatment of the sealing ring forging.

[0026] The following examples use a sealing ring forging with dimensions of Ø750×Ø550×130 as an example:

[0027] Example 1.

[0028] A method for preparing a 05Cr17Ni4Cu4Nb sealing ring forging, the specific steps of which are as follows:

[0029] Step 1: Preparation of Sealing Ring Billet: This step involves preparing the ring-shaped billet required for the high-strength, high-toughness sealing ring using a 05Cr17Ni4Cu4Nb forging process. An electroslag remelted steel ingot with dimensions of Ø500×2000 is used. The ingot is initially cut to 230×230×540 mm, then roughened from 540 mm to 135 mm, rolled, punched, and trimmed. Based on a forging ratio of approximately 1.35 for subsequent forging and hole enlargement, the ring-shaped billet is forged to dimensions of Ø600×Ø330×135 mm. The billet is then furnace-annealed at 680℃±10℃ for 5 hours.

[0030] Step 2, Performance Heat Treatment: The ring blank of 05Cr17Ni4Cu4Nb forging is heated to 1020℃±10℃ after rough turning. Then, the ring forging is expanded on a hydraulic press to Ø750×Ø550×130 in one pass. The deformation ratio during the forging process is about 1.35. The forging blank is turned over quickly and uniformly during the expansion. The tooling and auxiliary tools used for expansion are preheated to 350℃±20℃. When the ring expansion is completed, the surface temperature of the sealing ring forging is about 735℃. The forged sealing ring is then oil-cooled for solution treatment. After being oil-cooled to room temperature, the sealing ring forging is cryogenically treated with a mixture of liquid nitrogen and alcohol. The cryogenic treatment temperature is usually -50℃±5℃, and the temperature is held for 2 hours.

[0031] Step 3, Aging Treatment: The cryogenically cooled sealing ring forging is subjected to aging heat treatment at 480℃±10℃, with an aging holding time of 6h±0.5h. The tempering cooling method is air cooling, which completes the heat treatment of the sealing ring forging.

[0032] Sampling was performed on the heat-treated sealing ring forging from Example 1 at different positions: 0°, 90°, 180°, and 270°. The sampling positions were all 1 / 4T away from the outer circular surface and end face, where T is the heat treatment thickness. In this case, T is 100mm. This was done to verify the uniformity of mechanical properties in different parts of the forging.

[0033] Comparative Example 1.

[0034] A method for preparing a 05Cr17Ni4Cu4Nb sealing ring forging, the specific steps of which are as follows:

[0035] Step 1: Forging of the sealing ring: An electroslag steel ingot with dimensions Ø500×2000 is heated, then the ingot is blanked to 230×230×540. Subsequent blanks are roughened from 540 to 135, rolled, punched, and trimmed. Based on a forging ratio of approximately 1.35 for subsequent forging and hole enlargement, a ring-shaped blank is forged to dimensions Ø600×Ø330×135. After one heat treatment, the ingot is forged to dimensions Ø750×Ø550×130. The forging is then furnace annealed at 680℃±10℃ for 5 hours.

[0036] Step 2, Performance Heat Treatment: The forging is heated to 1040℃±10℃, followed by oil cooling solution treatment. Finally, the ring is cooled to room temperature by oil cooling. Then, the sealing ring forging is subjected to deep cryogenic treatment using a mixture of liquid nitrogen and alcohol at a temperature between -50℃±5℃.

[0037] Step 3, Aging Treatment: The cryogenically cooled sealing ring forging is subjected to aging heat treatment at 480℃±10℃, with an aging holding time of 6h±0.5h. The tempering cooling method is air cooling, which completes the heat treatment of the sealing ring forging.

[0038] Samples were taken from the heat-treated sealing ring forging of Example 2 at different positions of 0°, 90°, 180° and 270°. The sampling positions were 1 / 4T away from the outer circular surface and the end face, where T is the heat treatment thickness. In this case, T is 100mm. This was to verify the uniformity of mechanical properties in different parts of the forging.

[0039] Table 1. Mechanical test data of the examples and comparative examples.

[0040]

[0041] As can be seen from Table 1, the preparation method of Example 1 yields higher mechanical strength and better toughness compared to the preparation method of Comparative Example 1. The forgings manufactured using the preparation method of Example 1 show little difference in the measured mechanical properties at different sampling locations, indicating that the mechanical properties obtained by this manufacturing method are more stable and have a larger margin of mechanical properties. The performance of the sealing ring forgings manufactured by this invention has been improved to a certain extent, with good performance stability and little difference in the mechanical properties at different locations.

Claims

1. A method for preparing a high-strength and high-toughness 05Cr17Ni4Cu4Nb sealing ring forging, characterized in that, Includes the following steps: Step 1, Preparation of sealing ring blank: First, pre-fabricate the ring blank. The size of the ring blank is reserved according to the subsequent forging ratio. Then, the ring forging is annealed at 680℃±10℃ for 5 hours. After annealing, the outer end face and inner and outer surfaces of the forged ring blank are rough-machined. Before pre-fabricate the ring blank, the blank needs to undergo steelmaking and electroslag remelting treatment. Step 2, Deformation heat treatment: The annular billet from Step 1 is heated to 1020℃±10℃, and then the annular forging hole expansion process is completed on a hydraulic press. After the hole expansion of the annular billet is completed, the surface temperature of the forged sealing ring forging is 735℃. The forged sealing ring is subjected to oil cooling solution treatment. After being cooled to room temperature, it undergoes cryogenic treatment using a mixture of liquid nitrogen and alcohol at a temperature of -50℃±5℃. During the reaming process, the forging blank should be turned over quickly and uniformly. To prevent the blank temperature from dropping too rapidly, the reaming tooling is preheated to 350℃±20℃. The reaming is completed in one pass to achieve the required dimensions for the sealing ring forging. The deformation ratio is controlled at 1.35 during this forging process. Step 3, Aging Treatment: After the cryogenic treatment in Step 2, the sealing ring forging is subjected to aging heat treatment at a temperature of 480℃±10℃ and an aging holding time of 6h±0.5h. The tempering cooling method is air cooling, which completes the heat treatment and yields a high-strength and tough 05Cr17Ni4Cu4Nb sealing ring forging. The high-strength and toughness 05Cr17Ni4Cu4Nb sealing ring forging is composed of the following mass fractions: C≤0.04%, Si≤0.50%, Mn≤1.0%, P≤0.015%, S≤0.004%, Ni 4.50%~5.00%, Cu 3.00%~3.50%, Cr 15.00%~16.00%, Nb 0.15%~0.40%.

Images