Effect of slide burnishing on the corrosion resistance and surface roughness on high strength steels

This work presents an experimental study aimed to determining the influence of the slide burnishing force on the surface roughness indicators ( R a , R z , R t , R v , and R p ) and corrosion resistance on the advanced high strength steels TRIP-440Y and DP-330Y and the high strength steel HSLA-SP780. For each steel, the tests were carried out at different burnishing forces between 30 and 450 N, using a zig-zag burnishing toolpath with a 50% of the footprint width of the spherical tip as length between burnishing traces. The results showed that the optimal burnishing force to minimize surface roughness for HSLA-SP780, DP-330Y, and TRIP-440Y steels were 60, 150, and 180 N. These burnishing forces enhanced the roughness indicators between 40.3% and 73.4% for DP-330Y, from 57.5% to 83.2% for TRIP-440Y, and around 2.8% and 41.6% for HSLA-SP780. Corrosion tests exhibited that sliding burnishing does not affect the corrosion resistance of the steels, which are coated with a zinc layer. This result was confirmed by an X-ray diffraction analysis of the burnished samples. The corrosion current for all samples burnished and not burnished with zinc were close to 25 µA. Therefore, slide burnishing technique is an excellent option to improve the surface roughness without affecting the corrosion resistance of these steels, as well as other mechanical and physical properties that have been investigated according to the literature.