1996 Volume 45 Issue 7 Pages 785-791
Impact tension and compression tests on ferritic ductile cast iron were performed by means of the split Hopkinson bar technique. Tensile and compressive stress-strain data for the ductile cast iron were determined at the strain rates of over 103/s and compared with those obtained at quasi-static strain rates. The test results indicate that ductile cast iron has higher stress-strain characteristics in compression than in tension at low and high rates of strain. In an attempt to examine the different strength characteristics in tension and compression, microscopic examinations of the post-test specimens were conducted with an optical microscope and a scanning electron microscope. Furthermore, the microhardness tests were carried out to estimate the strength of spheroidal graphites in a ferritic matrix. It is found that this different mechanical behavior in tension and compression is mainly attributed to the presence of spheroidal graphites in the ferritic matrix of ductile cast iron.
