Heat Treatment of Metals ›› 2024, Vol. 49 ›› Issue (2): 8-15.DOI: 10.13251/j.issn.0254-6051.2024.02.002

• MICROSTRUCTURE AND PROPERTIES • Previous Articles     Next Articles

Evolution of copper-rich phases and antibacterial properties of 304Cu and 430Cu antimicrobial stainless steels

Mo Jinqiang1,2, Feng Guanghong1, Xu Mei2, Zhang Wei2, Deng Shuaishuai2   

  1. 1. Metallurgical Technology Institute, Central Iron and Steel Research Institute Co., Ltd., Beijing 100081, China;
    2. State Key Laboratory of Advanced Stainless Steel, Taiyuan Shanxi 030003, China
  • Received:2023-08-26 Revised:2023-12-16 Online:2024-03-27 Published:2024-03-27

Abstract: 304Cu and 430Cu antibacterial stainless steels were prepared by adding appropriate amount of Cu. By means of XRD, OM and TEM, the effect of different annealing temperatures on microstructure and antibacterial properties of the two steels was investigated, and the evolution of Cu-rich phases was analyzed. The results show that the microstructure of the 430Cu stainless steel is mostly composed of polygonal ferrite, with a small amount abnormally grown grains distributed locally, while the microstructure of the 304Cu stainless steel is composed of irregular austenite. The copper-rich phases in the 304Cu antibacterial stainless steel is round in shape, the number of which increases and the size grows with the increase of annealing temperature, though the growth rate becomes slower when the annealing temperature exceeds 850 ℃. While in the 430Cu antibacterial stainless steel, the size of copper-rich phases grows with the annealing temperature rising, and the shape of copper-rich phase changes from spherical or ellipsoid to rod when the annealing temperature reaches 900 ℃. After annealing at 850 ℃, both the 304Cu and 430Cu stainless steels exhibit excellent antibacterial properties, which can delay the spoilage process of soybean products and rice in contact with it, and it can also form a bacteriostatic environment around itself.

Key words: antimicrobial stainless steel containing Cu, austenite, ferrite, copper-rich phases, antibacterial properties

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