Effect of Nitrogen on Structure and Properties of Ultra-Fine Austenitic Stainless Steel

The structure and properties of ultra-fine austenitic stainless steel with different content of nitrogen made by mechanical alloy (MA) and the Spark Plasma Sintering (SPS) technology are studied in this paper. The XRD-pattern showed that sintered sample with nitrogen is single austenite, and sintered sample without nitrogen is composed of austenite and martensite. TEM showed grain size of sample all distributed in nanometer. The grain size of sample with nitrogen added in is smaller than sample without nitrogen added in. The result of mechanical property measurement showed that with the rise of nitrogen content, the hardness and abradability of sintered samples increased, and the tensile strength first increased then decreased. Measurement of polarization curve showed that corrosion resistance of sintered samples enhanced with rise of nitrogen.