Medium-carbon chromium-nickel-molybdenum alloy structural steel and surface quality control method thereof

The invention belongs to the technical field of preparation of medium-carbon chromium-nickel-molybdenum alloy structural steel, and particularly relates to medium-carbon chromium-nickel-molybdenum alloy structural steel and a surface quality control method thereof. The method comprises the steps that raw materials of the medium-carbon chromium nickel molybdenum alloy structural steel are sequentially subjected to smelting, continuous casting and rolling forming, and the medium-carbon chromium nickel molybdenum alloy structural steel is obtained; wherein in the smelting process, titanium microalloying treatment and aluminum and nitrogen control are carried out, and the titanium element content is controlled to be 0.0080-0.0120%; the rolling forming comprises low-temperature heating rolling, and the low-temperature heating temperature is 1220-1240 DEG C. Due to the fact that titanium microalloying treatment is adopted in the smelting process, aluminum and nitrogen are controlled, and low-temperature heating rol