Heat Treatment of Metals ›› 2024, Vol. 49 ›› Issue (5): 88-93.DOI: 10.13251/j.issn.0254-6051.2024.05.014

• PROCESS RESEARCH • Previous Articles     Next Articles

Effect of solution treatment and aging on microstructure and properties of 21-4NWNb alloy

Zang Kai, Wang Shouqian, Zhu Zhiyuan   

  1. School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang Jiangsu 212000, China
  • Received:2023-07-23 Revised:2024-03-07 Online:2024-05-25 Published:2024-06-28

Abstract: Effects of solution treatment and aging on microstructure and properties of 21-4NWNb alloy were investigated by means of XSL-4-12 box resistance furnace, ZEISS metallographic microscope, ZEISS Merlin Compact field emission scanning electron microscope, KB 30S automatic hardness test system, CMT5305 electronic universal testing machine, and JEM-2100F field emission transmission electron microscope. The results show that solution treatment can effectively improve the grain structure of the alloys. When the solution treatment temperature is in the range of 1150-1200 ℃, a large amount of carbides in the alloy almost completely dissolve into the austenite matrix, and the Nb(C, N) phases cannot completely dissolve even at the solution treatment temperature of 1200 ℃. The hardness of the alloy decreases with the increase of solution treatment temperature. The grain size of the alloy remains basically unchanged after different aging treatments. At higher aging temperatures (650-800 ℃), hardness of the alloy shows a trend of first increasing and then decreasing with the increase of aging temperature. After solution treatment at 1150 ℃ for 0.5 h and then aging at 750 ℃ for 4 h, the tensile strength of the 21-4NWNb alloy reaches 1042 MPa, and there is a (110)WN//(220)γ relationship between the WN precipitate phases in the alloy and the Fe matrix.

Key words: 21-4NWNb alloy, solution treatment and aging, microstructure, properties

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