The Hardness and Microstructure of The Modified 13Cr Steam Turbine Blade Steel in Tempered Conditions

Martensitic stainless steels were usually used for turbine blade. Their properties can be improved in various ways, such as by heat treatment. This paper reports the influences of tempering temperature on hardness and microstructure of the modified 13Cr martensitic stainless steels. Samples were austenitized at 1050C and tempered at 300, 400, 500, 550, 600, 650, and 700ºC. Hardness measurement was conducted by Rockwell C indentation and metallographic observation was conducted by scanning electron microscope (SEM). The results show that increasing tempering temperature until 500C can improve hardness. The microstructure formed consists of tempered martensite containing carbides M23C6. The presence of carbides can also increasing hardness. Increasing tempering temperaturefrom 500C to 650C can decrease Cr content of carbide. Internatioanl Journal of Engineering and Technology