High-strength austenitic stainless steel and preparation method thereof

Abstract

The invention discloses high-strength austenitic stainless steel and a preparation method thereof. The high-strength austenitic stainless steel comprises an austenitic stainless steel matrix as well as micron nitride, submicron oxide and nano oxide which are dispersed and distributed in the austenitic stainless steel matrix, wherein the micron nitride is TiN, the submicron oxide is Al2O3, and the nano oxide is Y-Al-O. During preparation, mixed powder A is subjected to laser melting forming; and then the structure property is controlled. The mixed powder A is obtained by ball-milling and mixing micron nitride and powder B; the powder B is obtained by ball-milling the submicron oxide and the powder C; the powder C is obtained by ball-milling nano oxide and austenite steel powder; and the nano oxide is obtained by carrying out ball milling and solid solution on nano Y2O3 and nano Al powder. The austenitic stainless steel is strengthened by introducing various particles with different sizes into the steel by utilizing an oxide metallurgy technology and a dispersion strengthening theory, the process and product reproducibility is good, the cleanliness is the same, and the structure and the performance are easy to control.

Description

technical field

[0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a high-strength austenitic stainless steel and a preparation method thereof. Background technique

[0002] The main pipeline of the primary circuit is one of the seven key equipment in the nuclear island. It is called the "aorta" of the nuclear power plant and belongs to the first-level nuclear component. The main pipeline connects the reactor pressure vessel, the steam generator and the reactor cooler pump, so that these devices form a closed circuit. Its main function is to transport pressurized water containing radioactive substances and maintain the integrity of the pressure boundary to prevent the leakage of radioactive substances. The main pipeline has to run for decades under the condition of high temperature and high pressure, the service environment is harsh, and the manufacturing technology requirements are high.

[0003] After the Fukush...

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