Duplex stainless steel has a dual existence of austenite and ferrite. Nitriding was conducted on duplex stainless steel at a temperature of 1100°C at various treatment times of 1h, 2.5h, 4.5h and 6h. Morphological study with scanning electron microscope, X-ray diffraction and optical microscope showed precipitation S phase at 4.5h and pearlite transformation at 6h from expanded austenite as a result of more nitrogen diffusion at ferrite phase. Hardness test was also conducted to investigate the effect of precipitates in respect to various times and it was observed that sample treated at 6h has the highest hardness value. XRD showed the precipitation of expanded austenite and precipitation of a new phase that is suggested to be pearlite which is responsible for the increase in hardness of the material. Subsequently, a hybrid layer was formed that enhanced the tribological properties of the heat treated DSS. This work has been able to show the precipitation of pearlite due to nitrogen at a high nitriding temperature with a corresponding treatment time of 6h. © 2019, Microscopy Society of Malaysia. All rights reserved.