Effects of Chemical Compositions and Structural Condition on Properties of Austenitic and Ferritic Cast Stainless Steels

Cast 18-8 stainless steels normally contain δ-ferrite, the amount of which depends mainly on the chemical composition.In this report, the effects of various alloying elements on the amount of ferrite and on the properties of the steels investigated by tensile, microscopic and corrosion tests were investigated with the following results.(1) The strength of the cast steels increased in proportion to the amount of ferrite in austenite, but the elongation lowered inversely.(2) For the same amount of ferrite, the alloying elements Si, Mn and Mo strengthened the cast steels in that order.(3) The corrosion resistance was not affected by the amount of ferrite, but it was vastly dependent on the variation and content of alloying elements.(4) No definite relation was observed between mechanical properties at 800°C and the amount of ferrite.