PENGARUH WAKTU ELECTROPLATING NIKEL-CHROM TERHADAP KEKERASAN DAN LAJU KOROSI DALAM MEDIA CAIRAN PBS PADA BAJA STAINLESS STEEL 304

Stainless steel 304 is widely available in the industrial sector, easy to set up. It is also cheaper, but higher corrosion rate than stainless steel 316L. Stainless steel 316L is widely used in medical applications as a bone connector plate. Selection of stainless steel 304 is in it aims to compensate for stainless steel 316L in terms of the corrosion rate, so that it is needed a process to decrease the corrosion rate of stainless steel 304, one way is by electroplating Ni-Cr. The objective of this research is to find out the effect of variations in the time spent on the process of electroplating Ni-Cr on hardness and the corrosion rate on stainless steel 304. Stainless steel 304 was coated nickel (Ni) and cromium (Cr) variated by electroplating time (8,17,25,30 and 40 minutes). Corrosion rate was tested using three-electrode cell with PBS media (Phosphate Baver Salin). Micro Vickers indentation was used for measuring surface hardness using load of 10 grams and FESEM was used to measuring thickness of the layer. The optimum time of surface hardness and the lowest corrosion rate are obtained on spesimen of stainless steel 304 by electroplating time of 17 minutes. Electroplating process can increase hardness and decrease the corrosion rate on the surface of stainless steel 304. Value of surface hardness on stainless steel 304 is 175 VHN0,01, after electroplating Ni-Cr increased by 61% to 282 VHN0,01. The rate corrosion of stainless steel 304 is 0.0009423 mm / yr, after electroplating Ni-Cr decreased by 60.9% to 0.000368 mm / yr