PURPOSE: To improve the yield, and to reduce the manufacturing cost by specifying the final lower limit cooling temperature on the surface of the cast slab of the prescribed contents in the continuous casting machine, and providing the prescribed draft after heating to the prescribed temperature.
CONSTITUTION: The molten steel has the composition consisting of, by weight, 0.2-0.8% C, ≤0.5% Si, 11-20% Mn, and ≤3% Cr. The molten steel is continuously cast, and the cast slab is hot rolled. The final lower limit cooling temperature T, on the surface of the cast slab in the continuous casting machine is given by the formula I. The cast slab is charged in the heating furnace while it is held at the temperature of ≥TL, and after heating it to the temperature range of 1050°C-1250°C, the hot rolling is executed with the draft to be provided in the first pass of the hot rolling being in the range of 3-6%. The draft is defined by the formula II. This constitution greatly improves the cracks to be generated in executing the hot rolling of the high manganese nonmagnetic steel cast slab.
SATO HIROSHI
SUGAWARA TAKESHI
YAMANAKA ATSUSHI
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