It is characterized by heating the steel plate to a temperature of about 30°C ~ 50°C or higher above the upper critical point of the ferrite-austenite transformation, so that the steel is austenitized, and after the heat preservation is homogenized, in the free atmosphere Medium cooling. Conventional normalizing heat treatment process, air cooling after normalizing, ferrite grains will still grow, resulting in lower strength of the steel plate. If a controllable cooling rate is used after normalizing, the phase transition temperature can be reduced, the type of phase transition can be controlled, the phase transition structure can be refined, and the carbonitrides of microalloying elements can be inhibited from growing, and the carbonitrides of the microalloying elements can be prevented from growing and dispersing and precipitated at low temperature. Improve the strength of the steel, and keep the toughness of the steel. From the perspective of composition design, under the condition of ensuring the same mechanical properties, the content of carbon or alloying elements in the steel can be reduced, thereby improving the weldability of the steel. For this reason, related researchers or manufacturers have carried out exploratory research and development on normalized cooling equipment and processes, and achieved certain results.