Method for predicting metallurgical bonding width of thermocompression interface of bimetal

Abstract

A method for predicting metallurgical bonding width of a thermocompression interface of bimetal belongs to the technical field of manufacturing of thermometal components and is characterized by comprising the following steps: 1) before thermocompression, taking a thermometal blank to a thermometal ring blank formed by a centrifugal casting process, and setting the diameter D0, the height H0 and the interface metallurgical bonding width B0 of the thermometal ring blank; and (2) after hot compression, the height of the bimetal blank is reduced to H, the diameter of the bimetal blank is increased to D, the interface metallurgical bonding width is increased to B, a relational expression between B and the deformation temperature T, the rolling reduction epsilon and the rolling reduction rate v is determined, and prediction of the interface metallurgical bonding width can be achieved by adjusting technological parameters in the hot compression process. The method has the advantages that the combination width can be simply and conveniently predicted through the mathematical model according to the given deformation temperature, rolling reduction and rolling reduction rate, and the bimetallic composite material with good interface combination is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of bimetallic component manufacturing, and in particular relates to a method for predicting the metallurgical bonding width of a bimetallic hot compression interface. Background Art

[0002] With the rapid development of the manufacturing and application of high-end equipment and its components (such as flanges and slewing support rings) in the fields of aerospace, deep-sea exploration and rail transportation, the requirements for the comprehensive performance of metal components are becoming more and more stringent. Components made of a single material are increasingly difficult to meet the service requirements under extremely complex working conditions. After the surface of a traditional single material is worn to a certain extent, it will cause a lot of waste due to unusability, which has led to the manufacture and application of bimetallic composite components. The unused part is replaced by other cheap materials, especially in applications where the performance requirements for the inner and outer sides of the components are inconsistent, which can achieve the purpose of saving costs and improving performance.

[0003] The bonding performance of bimetallic composites mainly depends on the bonding width of the bimetallic interface. However, in the current research on bimetallic composites, there is no unified design standard for the interface bonding width, and there is no clear standard for its relationship with the corresponding composite process parameters, which seriously affects the improvement of the bonding performance of bimetallic composites. Summary of the invention

[0004] The present invention provides a method for predicting the metallurgical bonding width of a bimetallic hot compression interface, which can effectively overcome the shortcomings of the prior art.

[0005] The object of the present invention is achieved by comprising the following steps:

[0006] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by a centrifugal casting process is taken. Along the height direction of the cylindrical bimetal billet, the upper side is a material with greater deformation resistance, and the lower side is a material with less deformation resistance. The geometric dimensions of the bimetal billet are set as: diameter D0, height H0, where the interface metallurgical bonding width after centrifugal casting is B0;

[0007] (2) After hot compression, the height of the cylindrical bimetallic billet is reduced to H, the diameter is increased to D, and the interface metallurgical bonding width is increased to B. The mathematical relationship between the interface metallurgical bonding width B and the temperature T, the pressing amount ε and the pressing rate v is determined. By adjusting the process parameters during the hot compression process, the interface bonding width can be predicted, that is:

[0008] B = 1 3 [ 1 . 41987 × exp ( T 768 . 5592 ) + 3 . 09952 × exp ( ε 0 . 76856 ) + 0 . 57687 × exp ( v 0 . 27882 ) − 6 . 84275 ]

[0009] According to step (2), the temperature T = 900 ~ 1200 ° C, the pressing amount ε = 30 ~ 60%, and the pressing rate v = 0.05 ~ 0.45 mm / s. The interface bonding width B can be determined based on the temperature, pressing amount and pressing rate.

[0010] According to step (2), the interface metallurgical bonding width can also be found from the following table:

[0011] Relationship between interface metallurgical bonding width B and hot compression process parameters

[0012]

[0013] Among them, the upper side material of the bimetal in step (1) can be a material with greater deformation resistance such as 40Cr steel, 42CrMo steel, 35CrMo steel, etc., and the lower side material can be a material with less deformation resistance such as Q345B, Q235B, 25Mn, etc.

[0014] Advantages and positive effects of the present invention: Since the present invention takes into account the differences in deformation temperature and reduction during the hot compression process, determines the relationship between the interface metallurgical bonding width B and the deformation temperature T, the reduction amount ε and the reduction rate v, for a hot-compressed bimetallic billet of a specific size, the interface metallurgical bonding width can be simply and quickly obtained by increasing the deformation temperature and the reduction amount, which can improve the efficiency of dimensional design and shorten the process time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the geometric dimension identification diagram of the bimetallic blank before and after hot compression;

[0016] In the figure: 1 - upper material 2 - lower material;

[0017] D0—diameter of bimetal billet before hot compression, H0—height of bimetal billet, B0—metallurgical bonding width of bimetal billet interface;

[0018] D—diameter of the bimetallic billet after hot compression, H—height of the bimetallic billet after hot compression, B—metallurgical bonding width of the interface of the bimetallic billet after hot compression. DETAILED DESCRIPTION

[0019] The following is a further description of a method for predicting the metallurgical bonding width of a bimetallic hot compression interface according to the present invention in conjunction with the accompanying drawings and specific examples.

[0020] Figure 1 This is a diagram showing the geometric dimensions of the bimetallic billet before and after hot compression.

[0021] Example 1

[0022] The bimetal hot compression process parameters of this embodiment are as follows: take a bimetal ring blank formed by a centrifugal casting process, along the height direction of the cylindrical bimetal blank, the upper side is a material with greater deformation resistance, and the lower side is a material with less deformation resistance. The hot compression method for predicting the interface metallurgical bonding width B is mainly achieved by changing the temperature T, the pressing amount ε and the pressing rate v. The design steps are:

[0023] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by centrifugal casting is taken. Along the height direction of the cylindrical bimetal billet, the upper side is a material with greater deformation resistance, and the lower side is a material with less deformation resistance. The geometric dimensions of the bimetal billet are set as: diameter 18 mm, height 27 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm;

[0024] (2) After hot compression, the height of the bimetallic billet is reduced to 18.9 mm and the diameter is increased to 21.52 mm. When the temperature is 900 °C, the reduction is 30% and the reduction rate is 0.05 mm / s, the interface metallurgical bonding width can be predicted:

[0025] B = 1 3 [ 1 . 41987 × exp ( T 768 . 5592 ) + 3 . 09952 × exp ( ε 0 . 76856 ) + 0 . 57687 × exp ( v 0 . 27882 ) − 6 . 84275 ] = 1 mm

[0026] Example 2

[0027] In this embodiment, the bimetal hot compression process parameters are set as follows: a bimetal ring blank formed by a centrifugal casting process is taken, and along the height direction of the cylindrical bimetal blank, the upper side is 40Cr steel and the lower side is Q345B steel. The hot compression method for predicting the metallurgical bonding width B of the 40Cr / Q345B interface is mainly achieved by changing the temperature T, the pressing amount ε and the pressing rate v. The design steps are:

[0028] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by centrifugal casting is taken. Along the height direction of the cylindrical bimetal billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetal billet are set as follows: diameter 18 mm, height 27 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm.

[0029] (2) After hot compression, the height of the bimetallic billet is reduced to 14.85 mm and the diameter is increased to 24.27 mm. When the temperature is 1050 °C, the reduction is 45% and the reduction rate is 0.3 mm / s, the interface metallurgical bonding width can be predicted:

[0030] B = 1 3 [ 1 . 41987 × exp ( T 768 . 5592 ) + 3 . 09952 × exp ( ε 0 . 76856 ) + 0 . 57687 × exp ( v 0 . 27882 ) − 6 . 84275 ] = 2 mm

[0031] Example 3

[0032] The process parameters of bimetal hot compression in this embodiment are as follows: take a bimetal ring blank formed by centrifugal casting process, along the height direction of the cylindrical bimetal blank, the upper side is 40Cr steel and the lower side is Q345B steel. The hot compression method for predicting the 40Cr / Q345B interface bonding width B is mainly achieved by changing the temperature T, the pressing amount ε and the pressing rate v. The design steps are:

[0033] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by centrifugal casting is taken. Along the height direction of the cylindrical bimetal billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetal billet are set as follows: diameter 18 mm, height 27 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm.

[0034] (2) After hot compression, the height of the bimetallic billet is reduced to 10.8 mm and the diameter is increased to 28.46 mm. When the temperature is 1200 °C, the reduction is 60% and the reduction rate is 0.45 mm / s, the interface metallurgical bonding width can be predicted:

[0035] B = 1 3 [ 1 . 41987 × exp ( T 768 . 5592 ) + 3 . 09952 × exp ( ε 0 . 76856 ) + 0 . 57687 × exp ( v 0 . 27882 ) − 6 . 84275 ] = 3 . 2 mm .

Claims

1. A method for predicting the metallurgical bonding width of a bimetallic hot compression interface, characterized in that To do this, follow these steps: (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by a centrifugal casting process is taken. Along the height direction of the cylindrical bimetal billet, the upper side is a material with greater deformation resistance, and the lower side is a material with less deformation resistance. The geometric dimensions of the bimetal billet are set as: diameter D0, height H0, where the interface metallurgical bonding width after centrifugal casting is B0; (2) After hot compression, the height of the bimetallic billet is set to be reduced to H, the diameter is increased to D, and the interface metallurgical bonding width is increased to B. The mathematical relationship between the interface metallurgical bonding width B and the temperature T, the pressing amount ε and the pressing rate v is designed. By adjusting the process parameters during the hot compression process, the interface bonding width can be predicted, that is: （1）。 2. A method for predicting the metallurgical bonding width of a bimetallic hot compression interface according to claim 1, characterized in that: Temperature T=900~1200 ℃, reduction ε=30~60%, reduction rate v=0.05~0.45 mm / s. The interface bonding width B can be predicted based on the temperature, reduction and reduction rate.

3. A method for predicting the metallurgical bonding width of a bimetallic hot compression interface according to claim 1, characterized in that: The interface metallurgical bonding width can also be found from the following table: Relationship between interface metallurgical bonding width B and hot compression process parameters 。 4. A method for predicting the metallurgical bonding width of a bimetallic hot compression interface according to claim 1, characterized in that: The upper side of the bimetal is made of materials with greater deformation resistance such as 40Cr steel, 42CrMo steel, 35CrMo steel, and the lower side can be made of materials with less deformation resistance such as Q345B, Q235B, 25Mn, etc.

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