Effect of Nitrogen on Structure and Property of Ultra-fine Austenitic Stainless Steel

The structure and property of ultra-fine austenitic stainless steel with different content of nitrogen made by mechanical alloy (MA) and the spark plasma sintering (SPS) technology are investigated. The XRD-pattern show that sintered sample with nitrogen is composed of single austenite, while that without nitrogen is composed of austenite and martensite. TEM shows the grain size of sample all distributes in nanometer. The grain size of sample with nitrogen is smaller than that without nitrogen. The hardness and abradability of sintered sample increase with the rise of nitrogen. The tensile strength of sintered sample increases at first and then decreases with the rise of nitrogen. Measurement of polarization curve shows that the corrosion resistance of sintered sample is enhanced with the rise of nitrogen.