Some high strength martensitic stainless steels, high speed tool steels and high strength alloy steels are produced due to high hardenability and strengthening of alloying elements. It is often tempered at high temperature after quenching (or tempering). Carbide steel is appropriately aggregated to form coarse carbide particles tempered sorbite structure (similar to spheroidizing annealing). Therefore, this kind of steel has good cutting performance. It is cooled directly after delivery, and is known as hot rolling or forging state. After hot rolling or forging, it does not undergo special heat treatment. Hot rolling (forging) termination temperature is generally 800-900 C, generally after natural cooling in the air, so the hot rolling (forging) state corresponds to normalization. Different from the strict standardized heating temperature control, the termination temperature of hot rolling (forging) is different. Therefore, it improves the microstructures and properties of the vibration ratio of steel.


1. Many iron and steel companies control rolling because finishing temperature control is very strict. After finishing rolling, forced cooling measures are taken to refine the grain size of steel and transport steel with high mechanical properties. Because the skin is covered with a layer of iron oxide, it has a certain degree of corrosion resistance, because strict storage requirements can not maintain the cold drawn (rolled) state of delivery steel, medium-sized steel, thick steel can be in open yard or through the thatch cover and storage of non-distorted and controlled cooling hot rod location is a fact, hot-rolled (forged) delivery state than ordinary steel hot rod performance.


2. The hardenability of cold-drawn (rolled) steel, without any heat treatment and direct transportation, cold-drawn, cold-rolled steel cold forming status. It is called cold drawing or cold rolling condition. Compared with hot-rolled (forged) state, cold-drawn steel has high precision in dimension (rolled) state, good surface quality, low surface roughness and high mechanical properties. Because the cold-drawn (rolling) delivery state has no scale steel shell, and has great stress, is vulnerable to corrosion or rust, so the cold-drawn (rolling) state steel, packaging, storage and transportation have more stringent requirements. Generally, under the supervision of the Ministry of Finance, the Ministry of Finance should pay attention to the delivery state in the temperature and humidity control state, called normalization. Due to the normalization of heating temperature (hypoeutectoid steel is Ac3 + 3050 degree C eutectoid steel, because the temperature of Accm + 3050 degree C is strictly controlled at the specific heat end,


3. Before normalizing the state of the steel plant and normalizing the heat treatment. In this way, the structure and properties of the steel are uniform. Compared with annealing state of steel, normalizing cooling rate is faster. The pearlite structure of steel increases the number of pearlite lamellae and refines the grain size of steel, so it has high mechanical properties, which is helpful to improve the carburized network of low carbon steel Widmanstatten and eutectoid steel, and to prepare the structure for further heat treatment products.