Quantification characterization of micropores in G20Mn5N cast steel at two different stages

Abstract

Cast steel is an important metal material that is widely used in civil engineering structures due to its high strength and good ductility. However, a variety of casting defects such as micropores are usually present in the as-cast components. Casting defects are the main factors leading to the degradation of mechanical properties. In this paper, X-ray tomography is used to quantify the quantity, size distribution of micropores in G20Mn5N cast steel. In the nine notched samples, the quantity of pores increases from 2726 in the undeformed stage to 6440 in the fractured stage. Compared with the undeformed stage, the total volume and the average volume of the micropores in the fractured stage are also increased. Furthermore, the distribution of equivalent pore diameter of the two stages is studied, which is consistent with the three-parameter lognormal distribution.