# Pengaruh Rasio Laju Alir Gas Nitrogen-Hidrogen serta Gas Pressure pada RF Plasma Nitriding terhadap Surface Hardness Spesimen SUS304

**Abstract**: RF Plasma nitriding was done on the specimen SUS304. The research had aim to obtain a high surface hardness value. The conducted research was experimental research and consisted of three experimental models. Each experimental model used varying parameters and constant parameters. Surface hardness test was conducted on each result of the experimental model. Surface hardness value of specimen was as a result of variations in the specified parameters in each of the experimental model. Surface hardness or micro hardness test method in the research was the Micro Vickers Hardness. For the first experimental model, the variable parameter was time of plasma nitriding, ie, 1 hour, 2 hours, 4 hours and 8 hours. Theconstant parameters were RF-Power Voltage = 250 Volts, DC-Bias Voltage = 500 Volts, N2= 100 (ml/min), H2= 20 (ml/min), Gas pressure (P) = 70 Pa and Heater Temperature (T) = 420oC. The second experimental model contained three variable parameters of nitrogen gas pressure ie, 50 Pa, 60 Pa and 70 Pa. The constant parameters of the second experimental model were time of plasma nitriding (t) = 8 Hours, RF-Power Voltage = 250 Volts, Heater Temperature (T) = 420oC, N2 = 140 (ml/min), H2= 20(ml/min). The first and second experimental models had the same configuration.The third experimentalmodel used three variations of the flow rate of nitrogen gas, ie, 140 (ml/ min), 160 (ml/min), 180 (ml/min). The constant parameters were time of plasma nitriding (t) = 4 hours, RF-Voltage = 250 volts, The Heater temperature (T) = 420oC; H2 = 20 (ml/min), DC-Bias Voltage = 500 Volts, the gas pressure (P) = 60 Pa.The configuration of third experimental model was different with the configurations in first and second experimental models.Values of surface hardness on the first experimental model for plasma nitriding time of 1 hour, 2 hours, 4 hours and 8 hours were; 379 HV, 348 HV, 474 HV and 387 HV.The surface hardness values of the second experimental model were 586 HV, 607HV, 249 HV. While the results of surface hardness value of the third experimental model were 313 HV, 574 HV, 677 HV. From the results of surface hardness of SUS304 specimen and observation of variable parameters could be concluded that the ratio between the flow rate of nitrogen and hydrogen gas into the vacuum chamber and gas pressure affected the value of the surface hardness. At the gas pressure of 60 Pa and the nitrogen gas flow rate of 180 (ml/min) obtained the highest surface hardness value of 677 HV.

**Penulis**: Tjuk Oerbandono

Kode Jurnal:

**jptmesindd160652**