Method for controlling bimetal coordinated deformation in hot compression process

Abstract

The invention discloses a method for controlling bimetallic coordinated deformation in a hot compression process, and belongs to the technical field of bimetallic component manufacturing. The method is characterized by comprising the following steps that (1) before hot compression deformation, a bimetallic material to be compressed is a cylindrical blank, a bimetallic ring piece formed through a hot rolling process is taken, the upper side of the bimetallic blank is a material with large deformation resistance, and the lower side of the bimetallic blank is a material with small deformation resistance; (2) a hot compression experiment is carried out on a numerical control oil press, firstly, the cylindrical blank is heated to the to-be-compressed temperature T, the low-speed compression rate is set to be v1, the achieved deformation is set to be epsilon 1, then the compression rate is increased to v2, and the achieved deformation is epsilon 2; the method has the advantages that the coordinated deformation of the two materials can be rapidly designed, the coordinated deformation capacity of the bimetallic material is controlled, and the design efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bimetal component manufacturing, and in particular relates to a method for controlling the coordinated deformation of bimetal during hot compression. Background Art

[0002] With the rapid development of aerospace, petrochemical, wind power, nuclear power and other industries, the performance requirements for ring parts are getting higher and higher. Single metal rings are increasingly difficult to meet the actual use requirements in terms of performance. Bimetallic rings can combine the advantages of two metal materials at the same time, maximize the complementary advantages of materials, and improve the performance, service life and reliability of parts.

[0003] The traditional manufacturing method of bimetallic rings is time-consuming and labor-intensive, and the bonding effect is not good. A new short-process manufacturing process for bimetallic rings uses bimetallic rings obtained by centrifugal casting to be directly hot-rolled and formed. It has high production efficiency and makes the metals on both sides and the bonding layer have better performance. However, due to the essential differences in the physical and mechanical properties of the metals on both sides, the deformation capacity of bimetallic rings during service is different. For example, if the coordinated deformation capacity of the metals on both sides under compressive loads is improved, so that the bimetallic material can undergo uniform plastic deformation, it will become the focus of bimetallic material research. At present, there is no unified standard to measure the coordinated deformation capacity of bimetallic materials. Summary of the invention

[0004] The present invention provides a method for controlling the coordinated deformation of bimetal during hot compression, 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 deformation, the bimetallic material to be compressed is a cylindrical billet, and a bimetallic ring formed by a hot rolling process is obtained. Along the height direction of the cylindrical bimetallic 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 bimetallic billet are set as: diameter D0, height H0, where the interface metallurgical bonding width after centrifugal casting is B0;

[0007] (2) The hot compression experiment was carried out on a CNC hydraulic press. The in-situ feedback system was used to control the deformation during the compression process. First, the cylindrical billet was heated to the compression temperature T, and the slow compression rate was set to v1, so that the soft phase Q345B first underwent plastic deformation. It was constrained by the hard phase 40Cr, and the deformation degree was limited, and the deformation reached was ε1. Then the compression rate was increased to v2, so that 40Cr underwent plastic deformation, and the deformation reached was ε2, which was higher than that of Q345B. Under the action of compression, the two deformed together to reduce the height and increase the diameter.

[0008] (3) Determine the mathematical model of the deformation ε1, ε2 of the two layers of material and the compression temperature T, compression rate v1 and v2, that is:

[0009] ε 1 = 1 2 [ 0 . 08354 × exp ( T 212 . 33393 ) + 1 . 2606 × exp ( v 1 0 . 32731 ) + 8 . 5394 ] (1)

[0010] ε 2 = 1 2 [ 0 . 09709 × exp ( T 210 . 38337 ) + 8 . 13121 × exp ( v 2 0 . 82178 ) + 3 . 82464 ] (2)

[0011] According to step (3), the deformation can also be found from the following table:

[0012] Relationship between deformation and hot compression process parameters

[0013]

[0014] According to step (1), the upper side of the bimetallic blank can be made of a material with greater deformation resistance, such as 40Cr steel, 42CrMo steel, 35CrMo steel, and the lower side can be made of a material with less deformation resistance, such as Q345B, Q235B, 25Mn, etc.

[0015] The advantages and beneficial effects of the present invention are as follows: since the present invention takes into account the differences in compression temperature and compression rate, the relationship between the deformation of the upper and lower side materials of the bimetallic blank and the compression temperature and compression rate is determined respectively. For a bimetallic blank of a certain size, the deformation of the upper and lower side materials of the bimetallic blank under different compression rates and compression temperatures can be simply, quickly and accurately calculated, and the hot compression coordinated deformation behavior of the bimetallic blank can be controlled, thereby improving the design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the geometric dimension identification diagram of the bimetallic material before and after hot compression;

[0017] In the figure: 1—material with greater deformation resistance 2—material with less deformation resistance;

[0018] D0—diameter of bimetallic material before hot compression, H0—height of bimetallic material, B0—interface bonding width of bimetallic material;

[0019] D—diameter of the bimetallic material after hot compression, H—height of the bimetallic material after hot compression, B—interface bonding width of the bimetallic material after hot compression. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is a diagram showing the geometric dimensions of the bimetallic material before and after hot compression.

[0022] Example 1

[0023] In this embodiment, the hot compression process parameters of the bimetallic ring are set as follows: compression temperature T = 900 °C, slow compression rate v1 = 0.1 mm / s, and boost compression rate v2 = 0.4 mm / s. The method for realizing hot rolling coordinated deformation of the bimetallic ring is mainly achieved through the following steps:

[0024] (1) Before hot compression deformation, the bimetallic material to be compressed is a cylindrical billet, and a bimetallic ring formed by hot rolling is obtained. Along the height direction of the cylindrical bimetallic billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetallic billet are set as follows: diameter 10 mm, height 30 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm;

[0025] (2) The hot compression experiment was carried out on a CNC hydraulic press. The in-situ feedback system was used to control the deformation during the compression process. First, the cylindrical billet was heated to the compression temperature T = 900 °C, and the slow compression rate was set to v1 = 0.1 mm / s, so that the soft phase Q345B first underwent plastic deformation. It was constrained by the hard phase 40Cr, and the deformation degree was limited, and the deformation reached was ε1. Then the compression rate was increased to v2 = 0.4 mm / s, so that 40Cr underwent plastic deformation, and the deformation reached was ε2, which was higher than that of Q345B. Under the action of compression, the two deformed together to reduce the height and increase the diameter.

[0026] (3) Determine the mathematical model of the deformation ε1 and ε2 of the two layers of material and the compression temperature and compression rate, that is:

[0027] ε 1 = 1 2 [ 0 . 08354 × exp ( 900 212 . 33393 ) + 1 . 2606 × exp ( 0 . 1 0 . 32731 ) + 8 . 5394 ] = 8 . 02 %

[0028] ε 2 = 1 2 [ 0 . 09709 × exp ( 900 210 . 38337 ) + 8 . 13121 × exp ( 0 . 4 0 . 82178 ) + 3 . 82464 ] = 12 . 02 %

[0029] Example 2

[0030] In this embodiment, the hot compression process parameters of the bimetallic ring are set as follows: compression temperature T = 1050 ° C, slow compression rate v1 = 0.6 mm / s, and boost compression rate v2 = 0.75 mm / s. The method for realizing hot rolling coordinated deformation of the bimetallic ring is mainly achieved through the following steps:

[0031] (1) Before hot compression deformation, the bimetallic material to be compressed is a cylindrical billet, and a bimetallic ring formed by hot rolling is obtained. Along the height direction of the cylindrical bimetallic billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetallic billet are set as follows: diameter 10 mm, height 30 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm;

[0032] (2) The hot compression experiment was carried out on a CNC hydraulic press. The in-situ feedback system was used to control the deformation during the compression process. First, the cylindrical billet was heated to the compression temperature T = 1050 °C, and the slow compression rate was set to v1 = 0.6 mm / s, so that the soft phase Q345B first underwent plastic deformation. It was constrained by the hard phase 40Cr, and the deformation degree was limited, and the deformation reached was ε1. Then the compression rate was increased to v2 = 0.75 mm / s, so that 40Cr underwent plastic deformation, and the deformation reached was ε2, which was higher than that of Q345B. Under the action of compression, the two deformed together to reduce the height and increase the diameter.

[0033] (3) Determine the mathematical model of the deformation ε1 and ε2 of the two layers of material and the compression temperature and compression rate, that is:

[0034] ε 1 = 1 2 [ 0 . 08354 × exp ( 1050 212 . 33393 ) + 1 . 2606 × exp ( 0 . 6 0 . 32731 ) + 8 . 5394 ] = 14 . 07 %

[0035] ε 2 = 1 2 [ 0 . 09709 × exp ( 1050 210 . 38337 ) + 8 . 13121 × exp ( 0 . 75 0 . 82178 ) + 3 . 82464 ] = 19 . 17 %

[0036] Example 3

[0037] In this embodiment, the hot compression process parameters of the bimetallic ring are set as follows: compression temperature T = 1200 ° C, slow compression rate v1 = 1 mm / s, and boost compression rate v2 = 1.2 mm / s. The method for realizing hot rolling coordinated deformation of the bimetallic ring is mainly achieved through the following steps:

[0038] (1) Before hot compression deformation, the bimetallic material to be compressed is a cylindrical billet, and a bimetallic ring formed by hot rolling is obtained. Along the height direction of the cylindrical bimetallic billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetallic billet are set as follows: diameter 10 mm, height 30 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm;

[0039] (2) The hot compression experiment was carried out on a CNC hydraulic press. The in-situ feedback system was used to control the deformation during the compression process. First, the cylindrical billet was heated to the compression temperature T = 1200 °C, and the slow compression rate was set to v1 = 1 mm / s, so that the soft phase Q345B first underwent plastic deformation. It was constrained by the hard phase 40Cr and the deformation degree was limited. The deformation reached was ε1. Then the compression rate was increased to v1 = 1.2 mm / s, so that 40Cr underwent plastic deformation. The deformation reached was ε2, which was higher than that of Q345B. Under the action of compression, the two deformed together to reduce the height and increase the diameter.

[0040] (3) Determine the mathematical model of the deformation ε1 and ε2 of the two layers of material and the compression temperature and compression rate, that is:

[0041] ε 1 = 1 2 [ 0 . 08354 × exp ( 1200 212 . 33393 ) + 1 . 2606 × exp ( 1 0 . 32731 ) + 8 . 5394 ] = 29 . 54 %

[0042] ε 2 = 1 2 [ 0 . 09709 × exp ( 1200 210 . 38337 ) + 8 . 13121 × exp ( 1 . 2 0 . 82178 ) + 3 . 82464 ] = 33 . 98 % .

Claims

1. A method for controlling the coordinated deformation of bimetal during hot compression, characterized in that To do this, follow these steps: (1) Before hot compression deformation, the bimetallic material to be compressed is a cylindrical billet, and a bimetallic ring formed by a hot rolling process is obtained. Along the height direction of the cylindrical bimetallic 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 bimetallic billet are set as: diameter D0, height H0, where the interface metallurgical bonding width after centrifugal casting is B0; (2) The hot compression experiment was carried out on a CNC hydraulic press. The in-situ feedback system was used to control the deformation during the compression process. First, the cylindrical billet was heated to the compression temperature T, and the slow compression rate was set to v1, so that the soft phase Q345B first underwent plastic deformation. It was constrained by the hard phase 40Cr, and the deformation degree was limited, and the deformation reached was ε1. Then the compression rate was increased to v2, so that 40Cr underwent plastic deformation, and the deformation reached was ε2, which was higher than that of Q345B. Under the action of compression, the two deformed together to reduce the height and increase the diameter. (3) Determine the mathematical model of the deformation ε1, ε2 of the two layers of material and the compression temperature T, compression rate v1 and v2, that is: （1） （2）。 2. A method for controlling the coordinated deformation of bimetal during hot compression according to claim 1, characterized in that: The deformation can also be found from the following table: Relationship between deformation and hot compression process parameters 。 3. A method for controlling the coordinated deformation of bimetal during hot compression according to claim 1, characterized in that: The upper side of the bimetallic billet may be made of a material with greater deformation resistance, such as 40Cr steel, 42CrMo steel, 35CrMo steel, and the lower side may be made of a material with less deformation resistance, such as Q345B, Q235B, 25Mn, and the like.

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