Micro Structural Characterization of CF 8C Alloy and Its Effect on Tensile Properties at Various Temperatures

摘要

CF 8C alloy is an Iron-Chromium-Nickel austenitic stainless steel. It is a cast grade of AISI 347 stainless steel. CF 8C is niobium stabilized alloy and is extensively used in various components of Gas Turbine Engine and Turbocharger. It has good strength and ductility up to 550°C. Corrosion resistance is better than other austenitic stainless steel due to the presence of Niobium. Microstructure of this alloy consists of carbides and delta (δ) ferrite within austenitic matrix. The distribution, size and amount of delta ferrite are dependent on material processing condition. This paper is an attempt to understand the effect of delta ferrite on uniaxial tension testing at a constant strain rate over a range of temperatures. Detailed microstructral study and elemental analysis using optical and SEM has been carried out to understand delta (δ) ferrite distribution.