Anodic electrochemical dissolution behaviors of SUS304 stainless steel and its surface characteristics by scanning electrochemical machining

The ultra-thin SUS304 strip is a key material for various engineering applications, including aerospace and electronic communication, due to its excellent corrosion resistance and machining precision. Cold rolling is the primary method for machining the SUS304 strip; however, as the thickness decreases, surface processing defects can emerge, resulting in low surface quality and affecting the properties of the SUS304 strip. Existing methods cannot simultaneously achieve low cost, high quality, and high efficiency. In this study, scanning electrochemical machining (SECM) was adopted to efficiently and cost-effectively improve machining quality through the straight reciprocating motion of the cathode. First, the anodic dissolution characteristics of SUS304 stainless steel immersed in 10 wt% NaNO 3 solution at 298.15 K were investigated, confirming the effectiveness of NaNO 3 as an electrolyte for SECM. It was found that high current density can result in low surface roughness. Subsequently, the SUS304 strip is machined by SECM. The machined surface is compared with that produced by cold rolling from four aspects. The results show that SECM significantly reduces surface roughness Sa and Sz, with reductions of 85.5% and 79.2%, respectively. Moreover, the surface hardness, residual stress, and frictional wear are essentially the same as those of the strip processed by cold rolling. These findings validate that SECM can be used to improve the surface characteristics of SUS304 strip after cold rolling.