PENGARUH VARIASI WAKTU SHOT PEENING DAN ELECTROPLATING Ni-Cr TERHADAP KEKASARAN PERMUKAAN, KEKERASAN DAN LAJU KOROSI DALAM MEDIA SBF PADA STAINLESS STEEL 304

Stainless steel (SS) has been known to use in the industrial sector and the medical world because of corrosion resistant, high strength and low maintenance. One metal that is used as a tool for connecting a broken bone is SS 304, because the material is cheap, plentiful and easily available in the market but higher than the corrosion rate of SS 316L. Shot peening and Ni-Cr electroplating a surface treatment method that can increase hardness and decrease the corrosion rate. This study aims to analyze penggaruh combined with shot peening surface treatment and electroplating Ni-Cr to the surface roughness, hardness, and corrosion rate on SS 304 on media SBF (Simulated Body Fluid) to obtain a connector plate bone implant material better. The process of shot peening on the surface of the specimen SS 304 with a time variation of 5, 10, 15, 20, 25 and 30 minutes, the material shot using a 0,6 mm diameter steel ball, steel ball hardness 40-50 HRc, working pressure of 6-7 ������, nozzle diameter of 5 mm, 9 mm diameter suction pipe and nozzle with a range between 10 cm specimen surface. Electroplating process of nickel (Ni) using a current of 0,03 A, the voltage of 2 V and a time of 15 minutes while the electroplating plating chromium (Cr) using the current 0,3 A, the voltage of 4,5 V and 5 minutes plating time. SS 304 specimens after treatment and then, the surface roughness was tested using tools model surfcoder SE 1700, a test was performed using a micro Vickers hardness Buchler Micromet 2100 series with a load of 100 grams and test corrosion rate using a galvanostat Model M 273 with SBF test media. The results showed that the longer time shot peening treatment and electroplating Ni-Cr can decrease the rate of corrosion, increasing the hardness and surface roughness of the specimen SS 304. Shot peening where treatment with a time of 30 minutes and electroplating Ni-Cr increase in the surface roughness of the SS 304 specimen value of average roughness (Ra) 0,1413 μm becomes 1,6690 μm, increasing the surface hardness of specimens of 230 ������ to 456 ������ and decrease the corrosion rate of 0,1588 mpy be 0 mpy. A minimum of treatment to offset the corrosion rate mpy 0,0477 and SS 316L specimens compatible implant material for bone connector plate obtained on specimens SS 304 SP15+Ni-Cr with surface roughness of 2,384 μm with corrosion rate 0,0218 mpy. Keywords: shot peening time, electroplating, stainless steel 304, corrosion rat