Process for preparing 3J78 precision alloy strip

Abstract

This invention provides a preparation process for 3J78 ​​precision alloy strip. The specific process flow is as follows: smelting, forging, hot rolling, solution heat treatment, repeated cold rolling annealing, and finished product heat treatment. The vacuum induction melting temperature is 1450℃~1500℃, the forging and hot rolling temperature is 1100℃~1150℃, the total deformation is 35%~70%, and the deformation per heat treatment is 15%~35%. The solution treatment temperature is 1100℃~1200℃, and the holding time is 20~40 minutes. During the intermediate annealing process between each cold rolling pass of the strip, the protective atmosphere is ammonia decomposition. The advantages of this invention are: the selection of a reasonable smelting method ensures the cleanliness of the raw materials; the subsequent use of a multi-roll cold rolling mill and continuous annealing furnace to formulate a reasonable rolling and heat treatment process ensures that the strip microstructure recrystallizes in each pass without producing defects such as cracks and pits; it effectively controls the deformation resistance of the alloy, resulting in a uniform and stable strip microstructure with good batch stability; and the process is simple and easy to operate.

Description

Technical Field

[0001] This invention relates to the field of strip manufacturing processes, and particularly to a manufacturing process for 3J78 ​​precision alloy strip. Background Technology

[0002] 3J78 alloy is a precision alloy material with nickel as the base material and reinforced by a combination of elements such as tungsten, chromium, cobalt, titanium, and aluminum. Due to its excellent mechanical and processing properties, it has been widely used both domestically and internationally. Its products include strips, wires, and bars, primarily used for machining various elastic parts such as wave springs.

[0003] For 3J78 ​​precision alloy strip, there are several main problems:

[0004] (1) The material processing is difficult

[0005] 3J78 precision alloy strip is difficult to form. The alloy contains many different elements, resulting in a narrow processing window. It also has low plasticity, high resistance to deformation, and is prone to cracking during the forming process.

[0006] (2) The research on strip forming process is not systematic and batch stability is insufficient.

[0007] To meet the final technical specifications during the strip fabrication process, control is required across various aspects, including raw materials, equipment capabilities, and process parameters. The δ0.35mm×240mm 3J78 ​​precision alloy strip provided by this invention has never been produced before. In-depth and systematic research is needed on the rational selection of equipment parameters, the optimal design of dimensions and materials, the deformation amount of different strip passes, the frequency of intermediate annealing, the strip speed during heat treatment, and the matching of these parameters. For example, excessive deformation during the rolling of the 3J78 ​​precision alloy strip billet can rapidly generate extremely high deformation resistance, causing the billet to crack after hardening, ultimately leading to product scrap. Furthermore, strips used in aero-engines have high requirements for dimensional accuracy and surface quality. If dimensions are out of tolerance or if there are metallurgical defects on the surface beyond the technical standards, the strip will still be unusable. Summary of the Invention

[0008] The purpose of this invention is to solve the problems existing in the background art and to provide a preparation process for 3J78 ​​precision alloy strip.

[0009] This invention provides a preparation process for 3J78 ​​precision alloy strip, the specific process flow of which is: smelting, forging, hot rolling, solution heat treatment, repeated cold rolling annealing, and finished product heat treatment.

[0010] The vacuum induction melting temperature is 1450℃~1500℃, the electroslag remelting voltage is 35V~45V, and the current is 4500A~5500A; the forging and hot rolling temperature is 1100℃~1150℃, the total deformation is 35%~70%, and the deformation per firing is 15%~35%.

[0011] Solution treatment temperature: 1100℃~1200℃, holding time: 20~40 minutes.

[0012] Cold rolling is performed at room temperature.

[0013] During the intermediate annealing process between each cold rolling pass of the strip, the protective atmosphere is ammonia decomposition, the annealing temperature is 1100℃~1200℃, and the belt speed is controlled at 2.0~2.5 m / min.

[0014] The rolling process from strip billet to strip involves six passes. The first pass uses a large deformation, with a rolling deformation of 58%. The deformation of the subsequent second to sixth passes is controlled between 18% and 24%.

[0015] After the finished product is processed, it undergoes solution heat treatment under a protective atmosphere of ammonia decomposition at a temperature of 1100℃~1200℃ and a conveyor belt speed of 2.0~2.5 m / min.

[0016] Compared with the prior art, the advantages of this invention are:

[0017] The preparation process of 3J78 ​​precision alloy strip described in this invention selects a reasonable smelting method to ensure the cleanliness of raw materials. Subsequently, a reasonable rolling and heat treatment process is formulated using a multi-roll cold rolling mill and a continuous annealing furnace, so that the strip microstructure recrystallizes in each pass and does not produce defects such as cracks and pits. This effectively controls the deformation resistance of the alloy, resulting in a uniform and stable strip microstructure with good batch stability. The process is simple and easy to operate. Attached Figure Description

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0019] Figure 1 This is a microstructure diagram of the finished strip from Example 1;

[0020] Figure 2 This is a microstructure diagram of the finished strip from Example 2;

[0021] Figure 3 This is a microstructure diagram of the finished strip from Example 3. Detailed Implementation

[0022] The present invention will be further explained below with reference to specific implementation schemes, but it is not limited to the present invention. The structures, proportions, sizes, etc. shown in the accompanying drawings are only used to complement the content disclosed in the specification, so as to enable those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0023] Example 1

[0024] The 3J78 ​​alloy ingot was cast through vacuum induction melting and electroslag remelting, then forged into a 20mm thick slab at 1100℃ with approximately 70% deformation. This slab was then hot-rolled into a 3mm strip at 1100℃, followed by solution heat treatment at 1100℃ for 30 minutes. The strip was then cold-rolled (with intermediate annealing between each cold rolling pass), ultimately producing a 3J78 ​​strip with a diameter of 0.35mm × 240mm. The microstructure of the finished product is shown in the figure. Figure 1 The rolling process parameters are shown in Table 1.

[0025] Table 1 Rolling process parameters of Example 1

[0026]

[0027] Example 2

[0028] The 3J78 ​​alloy ingot was cast through vacuum induction melting and electroslag remelting, then forged into a 20mm thick slab at 1150℃ with approximately 70% deformation. It was then hot-rolled into a 3mm strip at 1150℃, followed by solution heat treatment at 1150℃ for 30 minutes. This strip was then cold-rolled (with intermediate annealing between each cold rolling pass), ultimately producing a 3J78 ​​strip with a diameter of 0.35mm × 240mm. The microstructure of the finished product is shown in the figure. Figure 2 The rolling process parameters are shown in Table 2.

[0029] Table 2 Rolling process parameters in Example 2

[0030]

[0031] Example 3

[0032] The 3J78 ​​alloy ingot was cast through vacuum induction melting and electroslag remelting, then forged into a 20mm thick slab at 1150℃ with approximately 70% deformation. It was then hot-rolled into a 3mm strip at 1150℃, followed by solution heat treatment at 1200℃ for 30 minutes. This strip was then cold-rolled (with intermediate annealing between each cold rolling pass), ultimately producing a 3J78 ​​strip with a diameter of 0.35mm × 240mm. The microstructure of the finished product is shown in the figure. Figure 3The rolling process parameters are shown in Table 3.

[0033] Table 3 Rolling process parameters in Example 3

[0034]

[0035] Matters not covered in this invention are common knowledge.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for 3J78 ​​precision alloy strip, characterized in that: The process flow is as follows: vacuum induction melting, forging, hot rolling, solution heat treatment, repeated cold rolling annealing, and finished product heat treatment; the vacuum induction melting temperature is 1450℃~1500℃, the electroslag remelting voltage is 35V~45V, and the current is 4500A~5500A; the forging and hot rolling temperature is 1100℃~1150℃, the total deformation is 35%~70%, and the deformation per heat treatment is 15%~35%; the solution heat treatment temperature is 1100℃~1200℃, and the holding time is 20~40 minutes; cold rolling is performed at room temperature. The intermediate annealing process between each cold rolling pass of the strip is carried out in an ammonia decomposition protective atmosphere, with an annealing temperature of 1100℃~1200℃ and a belt speed of 2.0~2.5 m / min. The strip rolling process from billet to strip consists of 6 passes. The first pass uses a large deformation amount, with a rolling deformation amount of 58%. The deformation amount of the subsequent second to sixth passes is controlled at 18%~24%. After finishing, the strip undergoes solution heat treatment in an ammonia decomposition protective atmosphere at a treatment temperature of 1100℃~1200℃ and a belt speed of 2.0~2.5 m / min.

Images