Abstract
To improve the surface corrosion resistance of 42CrMo4 high-strength steel used in a marine environment, this article studied the effects of hard turning on the surface integrity and corrosion resistance of 42CrMo4 high-strength steel through the single factor experimental method, namely hard turning, polarization corrosion, electrochemical impedance spectroscopy, potentiodynamic polarization curve, and salt spray tests. The results indicated that the surface integrity was modified by the hard turning, with a surface roughness lower than Ra 0.8 μm, decreased surface microhardness, fine and uniform surface microstructure, and dominant surface residual compressive stress. The hard turning process was feasible to strengthen the surface corrosion resistance of 42CrMo4 high-strength steel. The better corrosion resistance of the surface layer than that of the substrate material can be ascribed to the uniform carbides and compact microstructure. The corrosion resistance varied with cutting speeds as a result of the changed surface microhardness and residual compressive stress, varied with feed rates as a result of the changed surface roughness, and varied with cutting depths as a result of the changed surface residual compressive stress, respectively. The surface integrity with smaller surface roughness and microhardness and bigger surface residual compressive stress was beneficial for corrosion resistance.
Highlights
As is known, hard machining has been widely used in the machine finishing of hardened steels [1,2,3]
Surface integrity has a significant impact on corrosion resistance, which directly affects the service life of parts [6,7]
It is important to study the influences of hard cutting on the surface integrity and corrosion resistance of 42CrMo4 high-strength steel and reveal the inherent relation between surface integrity and corrosion resistance
Summary
Hard machining has been widely used in the machine finishing of hardened steels [1,2,3]. It is important to study the influences of hard cutting on the surface integrity and corrosion resistance of 42CrMo4 high-strength steel and reveal the inherent relation between surface integrity and corrosion resistance. Zhang et al [17] reported that in the hard turning and low plasticity burnishing of Cr-Ni alloys, residual compressive stress and surface roughness were more important than grain refinement and microhardness in improving corrosion resistance. The studies on the effects of hard cutting on the surface integrity and corrosion resistance of 42CrMo4 high-strength steel are still insufficient, and the inherent relation between surface integrity and corrosion resistance needs deep research. The hard turning process was adopted to strengthen the surface integrity and corrosion resistance of 42CrMo4 high-strength steel and the inherent relation between surface integrity and corrosion resistance was revealed. This work can guide the practical production and application of the hard cutting process in strengthening the surface integrity and corrosion resistance of 42CrMo4 high-strength steel
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
