Microstructure and Corrosion Resistance of 40Cr Steel by Laser Melting

Abstract:

Laser melting was carryed out by HL-1500 CO₂ lase rmachine on 40 Cr steel. The phase composition, microstructure, microhardness and corrosion resistance of the melting coating were investigated by means of scanning electron microscope, X-ray diffractometer, electrochemical test system, salt spray tester etc. The result showed that, melt zone、transformation hardened zone and the heat affected zone as mainly region in melting coating. Laser melting coating constitute by Fe₃O₄, Fe₃C and martensite etc. The microstructure are mixed martensite and undissolved carbides, acicular martensite and retained austenite. The microhardness increased nearly twice as that of the 40Cr when scanning speed is 2.0 m/min. With the increase of the scanning speed, the corrosion resistance increased first and then decreased.

• Periodical: Advanced Materials Research (Volumes 189-193)
• Pages: 3717-3720
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.189-193.3717
• Online since: February 2011
• Authors: Xing Wu Qiu
• Keywords: 40Cr Steel, Corrosion Resistance, Laser Melting, Microstructure, Polarization Curve, Salt Spray Test

References

[1] Yali Gao, Cunshan Wang abd Hongbin Liu: Chinese Journal of Lasers Vol. 34(2007), pp.1019-1020, in Chinese.

[2] James, W. Sears, B. Han: Chinese Journal of Lasers Vol. 36(2009), pp.159-164.

[3] Q.M. Zhang, W.J. Liu: High Power Laser and Particle- beams Vol. 18(2006) 389-390, in Chinese.

[4] MUDALI U K, DAGAL R K: Mater Eng Perform Vol. 1 (1992), pp.341-343.

[5] Yide Kan, Wenjin Liu and Minlin Zhong: Applied Laser Vol. 27(2007), pp.3-5, in Chinese.