Microstructural control of FeB-inoculated mottled low-alloy white iron by a design of experiments approach

Abstract The present research identifies manufacturing factors that influence the metastable constituent in mottled Nihard cast irons. These irons constitute the roll shells of duplex work rolls processed by centrifugal casting. The research methodology employed a saturated design of experiments program with 7 factors, 8 experiments and a resolution of III. An increase from 6 to 10 kg/T of inoculated FeB enhanced metastable solidification by increasing the amount of ledeburite and the amount of cementite. Similarly, decreasing the Si content from 1.1 – 1.2 to 0.9 – 1.0 wt.% increased the amount of ledeburite and cementite. Finally, the use of casting machines without isolating sleeves increased the roll barrel hardness in the as-cast condition and after tempering.