Microstructure modification and corrosion improvement of AISI1045 steel induced by pseudospark electron beam treatment

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 469; pp. 10 - 18
• Main Authors: Fu, Yulei, Hu, Jing, Zhao, Wansheng, Peng, Fujun, Huo, Weijie, Cao, Xiaotong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2020
• Subjects: [formula omitted] steel; Amorphous state formation; Corrosion resistance improvement; Grain refinement; Pseudospark discharge; 99-00; Corrosion resistance improvement; 00-01; AISI1045 steel; Pseudospark discharge; Amorphous state formation; Grain refinement
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2020.02.033

The pseudospark electron beam is a kind of pulsed electron beam characterized by fast and stable repetitive operations. It is able to achieve high rate of energy rise and plasma quenching. Thus, when used as an intense electron beam source for material processing, some unique properties are induced. The mechanism analysis of microstructure modification and corrosion improvement of AISI1045 steel treated by pseudospark electron beam are investigated. Results show that the amorphous phase is formed on the top surface of melted layer. The treated layer is several microns deep with nonuniform interface. Besides, material’s grain sizes are significantly reduced after pseudospark treatment. The average grain size in the heat affected zone is smaller than that in the melted zone, which is attribute to the combination effect of temperature-induced dynamic thermal stress fields and the highest temperature gradient. Furthermore, electrochemical impedance spectroscopy (EIS) and potential polarization analysis are used to study the corrosion behavior of samples pre and post pseudospark electron beam treatment. The improvement of corrosion resistance is due to the combination effects of the formation of austenite, the removement of impurities during the electron beam surface treatment process and the formation of the amorphous phase acted as a homogeneous passive film.