Method for regenerating performances of aged duplex stainless steel under action of pulse current

A technology of duplex stainless steel and pulse current, applied in the field of metal material processing, can solve the problems of high cost and achieve the effect of saving energy and reducing temperature

Active Publication Date: 2018-07-24
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although annealing heat treatment can eliminate the aging and embrittlement phenomenon of duplex

Method used

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  • Method for regenerating performances of aged duplex stainless steel under action of pulse current

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] In this example, pulse current treatment is performed on the duplex stainless steel aged at 475° C. for 500 hours. Specific steps are as follows:

[0019] The first step: According to the aging degree of the duplex stainless steel, determine the parameter range of the pulse current. After optimizing the parameters, the optimal pulse current parameters are determined to be 150Hz, 180μs, 200A, and the action time is 1h.

[0020] The second step: Fix the aged duplex stainless steel with a fixture at the output end of the pulse power supply, and perform pulse current treatment for 1h at room temperature.

[0021] The third step: the hardness of ferrite in the duplex stainless steel after pulsed current treatment was measured by nanoindentation, and compared with the sample without pulsed current treatment. As shown in Table 1, after adopting the pulse current treatment method of the present invention, the hardness of the ferrite that undergoes amplitude modulation decompos...

Embodiment 2

[0023] In this example, pulse current treatment is performed on the duplex stainless steel aged at 475°C for 1000h. Specific steps are as follows:

[0024] The first step: According to the aging degree of the duplex stainless steel, determine the parameter range of the pulse current. After optimizing the parameters, the optimal pulse current parameters are determined to be 160Hz, 180μs, 200A, and the action time is 4h.

[0025] Step 2: Fix the aged duplex stainless steel with a fixture at the output end of the pulse power supply, and perform pulse current treatment for 4 hours at room temperature.

[0026] The third step: the hardness of ferrite in the duplex stainless steel after pulsed current treatment was measured by nanoindentation, and compared with the sample without pulsed current treatment. As shown in Table 1, after adopting the pulse current treatment method of the present invention, the hardness of the ferrite that undergoes amplitude modulation decomposition in t...

Embodiment 3

[0028] In this example, pulse current treatment is performed on cast duplex stainless steel aged at 400° C. for 20,000 hours. Specific steps are as follows:

[0029] The first step: According to the aging degree of the duplex stainless steel, determine the parameter range of the pulse current. After optimizing the parameters, the optimal pulse current parameters are determined to be 195Hz, 180μs, 200A, and the action time is 4h.

[0030] Step 2: Fix the aged duplex stainless steel with a fixture at the output end of the pulse power supply, and perform pulse current treatment for 4 hours at room temperature.

[0031] The third step: the hardness of ferrite in the duplex stainless steel after pulsed current treatment was measured by nanoindentation, and compared with the sample without pulsed current treatment. As shown in Table 1, after adopting the pulse current treatment method of the present invention, the hardness of the ferrite that undergoes amplitude modulation decompos...

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PUM

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Abstract

A method for regenerating the performances of aged duplex stainless steel under the action of pulse current, and belongs to the field of metal material processing. The method comprises the following steps: determining the aging degree of the aged duplex stainless steel, fixing the aged duplex stainless steel on a pulse power supply by a clamp, continuously applying a pulse for a corresponding timeto perform pulse treatment on the aged duplex stainless steel, and determining the parameters and the action time parameter of the pulse current according to the assessed ageing and brittleness degree of the duplex stainless steel, wherein the parameter ranges of the pulse treatment are as follows: the frequency is 1-200 Hz, the pulse width is 20 [mu]s to 1 ms, the current is 10-2000 A, and the action time is 1-6 h. The method is used to process aged and brittle duplex stainless steel in situ to restore the aged duplex stainless steel to an unaged state, and further reduces the temperature for eliminating the aging and the brittleness of the duplex stainless steel to save a lot of energy.

Description

technical field [0001] The invention belongs to the field of metal material processing, and particularly relates to a method for regenerating the performance of an aged duplex stainless steel under the action of a pulse current. Background technique [0002] As one of the cleanest, safest and most stable energy sources, nuclear energy has become the object of development by countries all over the world. At present, the number of nuclear power plants under construction and the total planned installed capacity in my country both rank first in the world. A large part of the nuclear power plant reactor types that have been built and planned to be built in my country are pressurized water reactors. The primary circuit main pipeline and main pump casing of the second-generation pressurized water reactor nuclear power plant are made of duplex stainless steel. Duplex stainless steel not only has excellent thermal crack resistance, corrosion resistance, stress corrosion crack resist...

Claims

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Application Information

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IPC IPC(8): C21D10/00
CPCC21D10/00
Inventor 张新房刘学兵
Owner UNIV OF SCI & TECH BEIJING
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