Analysis of large inclusions in high chromium steel composite roll working layer produced by centrifugal casting and the control measures

The morphology and formation process of large inclusions in centrifugal casting process of high-chromium steel composite roll working layer is analyzed. The morphology and main component of inclusions in high-chromium steel composite roll working layer was observed by optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), which makes sure that large inclusions belongs to foreign inclusions containing O, Na, Si and other major elements. And the morphology and chemical composition of sodium bentonite and zircon powder used in the casting process was observed by SEM, EDS and X-ray fluorescence spectrometry (XRF). By comparing, the main source of large inclusions in high-chromium steel composite roll working layer was sodium bentonite used in centrifugal casting mold drum. What's more, the formation process of inclusions was analyzed and the rising speed was calculated. Finally, the three measures to prevent foreign inclusions are given.