Laser & Optoelectronics Progress, Volume. 57, Issue 3, 031402(2020)
Microstructure and Corrosion Behaviors of 316L Coating Fabricated by Laser Cladding
In the present study, a 316L coating is deposited on the surface of 45# steel substrate using laser cladding technology to improve the corrosion resistance of the metal parts. The hardness, microstructure, and crystal morphology of the coating are characterized by optical microscope,energy dispersive spectroscopy, scanning electron microscopy, microhardness tester, and other equipment. The results show that the coating exhibits good metallurgical bonding with the substrate under certain processing parameters, and that the main crystal type is austenite with the existence of a small amount of Cr23C6 in the intergranular region. The crystal dimensions of the 316L coating increase with increase in the energy density, while the hardness of the surface subsequently decreases. When the energy density is less than or equal to 19 J·mm -2, the coating is prone to spheroidization and roughening. However, when the energy density is too high, the surface of the coating will overheat, resulting in the burning of some elements. Thus, some of the elements are lost owing to the degradation in performance. Moreover, according to the analysis of corrosion morphology, the main type of corrosion failure of the 316L coating is intergranular corrosion, and a small number of corrosion pits occur in the coating as well. With increase in intergranular corrosion, the 45# steel substrate begins to corrode, leading to the formation of an oxide film.
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Peng Liu, Zhikai Chen, Quanming Jin, Qinghai Zhu. Microstructure and Corrosion Behaviors of 316L Coating Fabricated by Laser Cladding[J]. Laser & Optoelectronics Progress, 2020, 57(3): 031402
Category: Lasers and Laser Optics
Received: May. 29, 2019
Accepted: Jul. 25, 2019
Published Online: Feb. 17, 2020
The Author Email: Chen Zhikai (chenzhikai2004@126.com)