Laser & Optoelectronics Progress, Volume. 57, Issue 1, 011405(2020)
Microstructure and Properties of 40CrNiMoA Steel Surface After Laser Quenching
In this study, a laser-quenching experiment is conducted on the 40CrNiMoA steel base material of a reel spindle using a fiber laser. Further, the microstructure of sample surface is observed using a metallographic microscope, the microhardness of the phase-transformation hardening zone is evaluated using a Vickers hardness tester, and the friction and wear properties of the sample are evaluated using a vertical universal friction-and-wear tester. The macroscopic structure of the sample cross-section and morphology after wear are observed using a stereo microscope, and the corrosion resistance of the sample is verified using an electrochemical workstation. The results denote that after laser quenching of the 40CrNiMoA steel, a phase-transformation hardening zone can be observed on the surface with a microstructure that is mainly characterized by fine martensite, a small amount of retained austenite, and partially dispersed carbides. The hardened layer exhibits a depth of approximately 200 μm, and the hardness can become 638.3--711.2 HV, which is approximately 2.6--2.8 times that of the substrate. The average friction coefficient is 0.506, which is 42.5% lower than that of the substrate. The amount of wear is 1.3 mg, which is only 36.1% of that of the substrate. Herein, the abrasive wear is observed to be the main wear mechanism. Furthermore, the corrosion voltage is -0.497 V, which is slightly higher than that of the substrate, while the self-corrosion current density is 2.16789×10 -9 A/cm 2, which is lower than that of the substrate. The corrosion resistance is considerably improved.
Get Citation
Copy Citation Text
Zhen Yang, Xiangfang Fan, Changjun Qiu, Yong Li, Ning Liu. Microstructure and Properties of 40CrNiMoA Steel Surface After Laser Quenching[J]. Laser & Optoelectronics Progress, 2020, 57(1): 011405
Category: Lasers and Laser Optics
Received: May. 10, 2019
Accepted: Jul. 15, 2019
Published Online: Jan. 3, 2020
The Author Email: Fan Xiangfang (hefanyibang@163.com)