Manufacturing method of high manganese steel slab, manufacturing method of high manganese steel slab and high manganese steel sheet

摘要

Provided are a method for manufacturing a high manganese steel slab or steel sheet capable of controlling inclusions and precipitates that determine a crystal grain size and suppressing the occurrence of surface flaws, and a method for manufacturing a high manganese steel slab used in their production. As a manufacturing method of a high manganese steel slab, in the continuous casting of molten steel containing a specific component composition, the content of Ca, O and S of the molten steel in the tundish satisfies the following formula (1): manufacturing method. 0.4 ≤ ACR ≤ 1.4...(1) ACR of the said (1) formula is computed by following (2) formula. ACR = {[%Ca] - (0.18 + 130 × [%Ca]) × [%O]}/(1.25 × [%S]) ... (2) [%Ca] in the formula (2) is the content of Ca in the molten steel (mass%), [%O] is the content of O in the molten steel (mass%), and [%S] is the content of S in the molten steel content (mass %).