Abstract: A die steel with a high thermal diffusion coefficient includes 0.30-0.40 wt. % of C, 0.05-0.10 wt. % of Si, 2.50-3.40 wt. % of Mo, 0.01-0.05 wt. % of Nb, 0.30-0.50 wt. % of Co, 0.01-0.05 wt. % of RE, the rest is Fe and unavoidable impurities, wherein in the die steel, P?0.15 wt. %, S?0.025 wt. %. A preparation method of the die steel includes steps of melting, electroslag remelting, electroslag ingot annealing, forging, spheroidizing annealing, quenching and tempering.

Abstract: A steel ladle drainage method, is achieved by using a steel ladle structure. Vacuum interlayers are provided within an upper nozzle, an upper fixed plate, alower fixed plate and a sliding plate of the steel ladle structure respectively. In the steel ladle drainage method provided by the present invention, a metal drainage agent is used to replace the drainage sand in the prior art, the metal drainage agent is melted by the liquid steel and deposited in the upper nozzle, the sliding plate with the vacuum interlayer and the upper nozzle with the vacuum interlayer have the insulation effect on the melted metal drainage agent, agent falling. Moreover, through moving the sliding plate, the two pouring holes of the upper and lower fixed plates are connectedwith each other, the metal drainage agent enters the tundish through the pouring holes and the lower nozzle under the action of gravity.