Abstract: Ultrasonic shot peening was first applied to strengthen the plow surface of 65Mn steel, followed by laser processing to create bionic clam shell micro-texture for reducing adhesion and drag. A shot-peening/bionic clam shell micro-texture composite modified layers with texture ratios of 19%, 23% and 37% were formed, and tribological properties tests were conducted under lubrication with artificially prepared earthworm fluid by using the HSR-2M reciprocating friction and wear tester. The hardness and surface roughness of the specimens were measured by using HV-1000D Vickers hardness tester and TR200 roughness tester, respectively. Surface structure and wear scar morphology were observed by using M330BD-HK830 metallurgical microscope and S-4800FE scanning electron microscope. The results show that ultrasonic shot peening alone increases the surface roughness of the 65Mn steel plow, which leads to an increase in the friction coefficient, while the improved hardness enhances wear resistance. The single bionic clam shell micro-texture with a texture ratio of 23%, without shot peening, provides limited improvement in the friction-reducing and wear-resistance of the 65Mn steel plow, reducing the friction coefficient and wear rate by 4.83% and 29.18%, respectively, compared to the unpeened and untextured specimen. Both shot peening and bionic clam shell micro-texture improve the friction-reducing and wear-resistant properties of the 65Mn steel plow to varying degrees. The specimen with texture ratio of 37% exhibits the best friction-reducing and wear-resistant properties, with maximum reductions in the friction coefficient and wear rate of 23.45% and 86.77%, respectively, compared to the unpeened and untextured specimen.

Key words: 65Mn steel plow surface, shot peening, bionic clam shell micro-texture, tribological properties