The hot rolling technolodge of nm400 weathering steel

Q370qC, Q370qD, NM400 weathering steel and Q370qE are structural steel plates for bridges. It is required to have high strength, toughness and to withstand the load and impact of rolling stock, and have good fatigue resistance, certain low temperature toughness and atmospheric corrosion resistance. The steel for tie-welding bridges should also have good welding performance and low notch sensitivity. Used for the production of riveted and bolt-welded road bridges and railway bridges (including cross-sea bridges).

Alloying elements can strengthen the properties of structural steels. NM400 weathering steel, Alloy structural steel has suitable hardenability. After proper metal heat treatment, the microstructure is uniform sorbite, bainite or very fine pearlite. Therefore, alloy structural steel has higher tensile strength and yield ratio (generally about 0.85), higher toughness and fatigue strength, and lower ductile brittle transition temperature. Alloy structural steel can be used to manufacture machine parts with larger section size.

S355J2 steel plate NM400 weathering steel rolling process is controlled rolling process. In the rolling process, the ingot rolling temperature is 1000-1050℃; in the first stage, the low-speed and large reduction rolling process is adopted, the high-temperature stage is 950-1000℃, the rolling speed is 1.6-2.0m/s, the NM400 weathering steel single reduction rate is 15-20%, and the cumulative reduction rate is 40-45%, so as to ensure sufficient deformation of ingot. In the first stage, the start rolling temperature is 910-930℃, and the finish rolling temperature is ≤ 870℃.

Compared with other fast-moving consumer goods, steel consumption is obviously different, with a wide range of use and a long service life. Therefore, the quality and service of steel materials are particularly important. Service is always one of our top concerns, especially after-sales service. We have mature after-sales service team, and can help you solve problems professionally during application of the steel materials.