Development of continuous slab casting technology with dimensions of (300–400) mm × (2000–2500) mm OF high-alloy martensitic steel

This study discusses the problem of continuous casting of high-alloy, martensitic steel into a (300–400) mm × (2000–2500) mm slabs for production of a 70–100 mm thick sheet. At the beginning of the technology development, the specialists encounter the formation of a considerable number of surface defects in the slabs, such as “scabs,” “longitudinal cracks along the scabs,” and “flash.” The causes of the defects are determined during the course of this study. The shrinkage in the steel sample is measured, and that in the ingot crust in the casting mold is calculated. A new mold setting (tapering) is developed. The submerged nozzle design and slag-forming mixture composition for the mold are optimized. A new polynomial for calculating the liquidus temperature of high-carbon, high-chromium steels is developed and tested in practice. The use of the developed algorithm enabled to optimize the overheating of the steel.

The application of the technology developed has considerably enhanced the quality of the slabs.