Method for achieving TWIP steel superplasticity based on deformation twin degradation

Abstract

The invention discloses a method for achieving TWIP steel superplasticity based on deformation twin degradation. The method comprises the following steps that (1) a TWIP steel bar in the perfect recrystallization state is selected and is stretched under the room temperature, the stretching deformation rate is 1-10 mm / s, and the stretching deformation quantity is 40%; (2) deformation twin degradation treatment is conducted, the stretched TWIP steel bar is subjected to heat preservation, so that deformation twin degradation and disappearance occur in the structure of the stretched TWIP steel bar, the temperature is 650-850 DEG C, heat preservation is conducted for 30-60 min, and quenching is conducted after heat treatment; (3) the quenched TWIP steel bar is stretched under the room temperature, the stretching deformation rate is 10<1>-1 mm / s, and the stretching deformation quantity is 30%; and (4) the (2)-(3) steps are repeated, and thus the total elongation after deformation is larger than 100%, that is, superplasticity is achieved. Through the method, the problems that the deformation quantity of the TWIP steel bar is too large in the hot rolling process, consequently, deformation resistance is large, cracks are liable to be produced, and the superplasticity forming rate is low are solved.

Description

technical field

[0001] The invention belongs to the technical field of metal material forming and superplastic deformation, in particular to a method for realizing superplasticity of TWIP steel based on deformation twin degeneration. Background technique

[0002] TWIP (Twinning induced plasticity) steel, also known as twinning induced plasticity steel, generally contains more than 15% manganese, so it is also a high manganese steel. TWIP has a high strain hardening rate, which is derived from the high-density deformation twins generated during plastic deformation, and the interaction of these micro-nano scale deformation twin boundaries with dislocations and grain boundaries causes significant work hardening. However, it is the above-mentioned interaction that causes the deformation resistance of TWIP steel to increase rapidly during rolling, and it is easy to crack, which greatly increases the difficulty of plastic forming of TWIP.

[0003] The superplasticity of metal mat...

Examples

Embodiment 1

[0035] 1) TWIP steel bar is used, and its microstructure is shown in figure 1 , stretch it at room temperature, the tensile deformation rate is 1mm / s, the deformation amount is 40%, the microstructure after stretching can be seen figure 2 ;

[0036] 2) Deformation twin degeneration treatment, holding temperature: 650°C, holding time 60min, quenching after heat treatment, the microstructure after quenching can be seen image 3 ;

[0037] 3) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 1mm / s, and the deformation amount is 30%;

[0038] 4) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 60min, and quenching is carried out after heat treatment;

[0039] 5) Stretch the TWIP steel bar at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0040] 6) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 60min, and quenchin...

Embodiment 2

[0043]1) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 5mm / s, and the deformation amount is 40%;

[0044] 2) Deformation twin degeneration treatment, the holding temperature is 850°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0045] 3) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 1mm / s, and the deformation amount is 30%;

[0046] 4) Deformation twin degeneration treatment, the holding temperature is 850°C, the holding time is 30min, and quenching is carried out after heat treatment. After quenching, the microstructure can be seen Figure 4 ;

[0047] 5) Stretch the TWIP steel bar at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0048] 6) Deformation twin degeneration treatment, the holding temperature is 850°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0049] After measurement, the total e...

Embodiment 3

[0051] 1) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 10mm / s, and the deformation amount is 40%;

[0052] 2) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0053] 3) The TWIP steel bar is stretched at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0054] 4) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0055] 5) Stretch the TWIP steel bar at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0056] 6) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 30min, and quenching is carried out after heat treatment. After quenching, the microstructure can be seen Figure 5 .

[0057] from Figure 5 It can be se...

technical field

[0001] The invention belongs to the technical field of metal material forming and superplastic deformation, in particular to a method for realizing superplasticity of TWIP steel based on deformation twin degeneration. Background technique

[0002] TWIP (Twinning induced plasticity) steel, also known as twinning induced plasticity steel, generally contains more than 15% manganese, so it is also a high manganese steel. TWIP has a high strain hardening rate, which is derived from the high-density deformation twins generated during plastic deformation, and the interaction of these micro-nano scale deformation twin boundaries with dislocations and grain boundaries causes significant work hardening. However, it is the above-mentioned interaction that causes the deformation resistance of TWIP steel to increase rapidly during rolling, and it is easy to crack, which greatly increases the difficulty of plastic forming of TWIP.

[0003] The superplasticity of metal mat...

Examples

Embodiment 1

[0035] 1) TWIP steel bar is used, and its microstructure is shown in figure 1 , stretch it at room temperature, the tensile deformation rate is 1mm / s, the deformation amount is 40%, the microstructure after stretching can be seen figure 2 ;

[0036] 2) Deformation twin degeneration treatment, holding temperature: 650°C, holding time 60min, quenching after heat treatment, the microstructure after quenching can be seen image 3 ;

[0037] 3) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 1mm / s, and the deformation amount is 30%;

[0038] 4) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 60min, and quenching is carried out after heat treatment;

[0039] 5) Stretch the TWIP steel bar at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0040] 6) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 60min, and quenchin...

Embodiment 2

[0043]1) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 5mm / s, and the deformation amount is 40%;

[0044] 2) Deformation twin degeneration treatment, the holding temperature is 850°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0045] 3) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 1mm / s, and the deformation amount is 30%;

[0046] 4) Deformation twin degeneration treatment, the holding temperature is 850°C, the holding time is 30min, and quenching is carried out after heat treatment. After quenching, the microstructure can be seen Figure 4 ;

[0047] 5) Stretch the TWIP steel bar at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0048] 6) Deformation twin degeneration treatment, the holding temperature is 850°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0049] After measurement, the total e...

Embodiment 3

[0051] 1) Stretch the TWIP steel bar at room temperature, the tensile deformation rate is 10mm / s, and the deformation amount is 40%;

[0052] 2) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0053] 3) The TWIP steel bar is stretched at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0054] 4) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 30min, and quenching is carried out after heat treatment;

[0055] 5) Stretch the TWIP steel bar at room temperature, and the tensile deformation rate is 10 -1 mm / s, deformation is 30%;

[0056] 6) Deformation twin degeneration treatment, the holding temperature is 650°C, the holding time is 30min, and quenching is carried out after heat treatment. After quenching, the microstructure can be seen Figure 5 .

[0057] from Figure 5 It can be se...

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