The Construction of Superhydrophobic Structure on Stainless Steel by an Optimized Chemical Etching Technics

Austenitic stainless steel is a widely used engineering material in industry and daily life due to its excellent corrosion resistance. The construction of superhydrophobic structure on stainless steel can endow it with special wetting properties and open up new paths for its application. In this study, stainless steel plate was first etched in an hydrofluoric acid solution with a low concentration of 40 wt.%, and a micro-nano structure was obtained in a short time of 2 hours. The surface was then modified in myristic acid to achieve superhydrophobicity. The superhydrophobic structure on the steel showed a high contact angle of 166°, excellent self-cleaning performance and greatly improved corrosion resistance compared with the original counterpart. Meanwhile, its wear durability was evaluated by sandpaper abrasion test and the superhydrophobic structure maintained its property after moving 125 cm on the 1000-grit sandpaper under a pressure of 3.2 kPa.

Residual stress and simulation of 304–430 stainless steel dissimilar laser-welded joints incorporating materials heterogeneity

An Nd:YAG laser device is used to conduct laser welding for a 1 mm austenitic stainless steel plate and a ferritic stainless steel plate. A finite element model of the shear punching test is constructed to generate the maximum shear strength in the weld, and the finite element model of laser welding is created using the welding temperature field. The hole drilling test result and the residual stress generated by two algorithms (Nonuniform-material and uniform-material) are compared. Results show that a drop-off of residual stress in the central area of the welded joint is observed when materials heterogeneity is disregarded. When materials heterogeneity is considered, the residual stress curve indicates smooth transition. The value of the latter appears reasonably similar to the experimental value. Therefore, this solution is advantageous in terms of residual stress simulation in dissimilar welded joints and does not critically affect residual deformation.