nm400 steel grade standard and specificaiton

Q420q material is a kind of structural steel plate for bridges, and there are three quality levels Q420qD, Q420qE and Q420qF. When the Q420q plate is required to have the performance in the thickness direction, the symbols Z15, Z25, Z35 representing the performance level in the thickness direction are added after the above-mentioned grades. Namely Q420qDZ15, Q420qDZ25, Q420qDZ35, Q420qEZ15, Q420qEZ25, Q420qEZ35, Q420qFZ15, Q420qFZ25, Q420qFZ35.

The company adheres to the "variety, quality and efficiency" road. We have established a technology center, a brand cultivation management system and a quality control system. Now the company has formed an independent innovation system integrating NM400 steel grade production, learning, research and marketing. Our company has passed ISO9001 quality management system certification and ISO10012 measurement management system certification.

The main applications of normalizing are as follows:① For low carbon steel, NM400 steel grade. The hardness of low carbon steel after normalizing is slightly higher than that after annealing, and the toughness is also better, so normalizing can be used as the pretreatment of cutting.② For medium carbon steel, normalizing can be used as the final heat treatment instead of quenching and tempering treatment, or as the preparation treatment before surface quenching by induction heating.③ Normalizing can be used in tool steel, bearing steel, carburizing steel and so on, which can eliminate or inhibit the formation of network carbide, thus obtaining the good microstructure needed for spheroidizing annealing.④ Normalizing can refine the cast structure and improve the machinability of steel castings.

The effect of nitrogen on steel performance is similar to that of carbon and phosphorus. With the increase of NM400 steel grade nitrogen content, the strength of steel can be improved, plasticity especially toughness can be significantly reduced, weldability becomes worse, and cold brittleness is intensified. Nitrogen with aluminum, niobium, vanadium and other elements can reduce its adverse effects, improve the performance of NM400 steel grade steel, can be used as an alloying element of low alloy steel.

As one of the large professional metallurgical manufacturers in China, the strength of the brand, quality assurance, professional after-sales. Every day we are making unremitting efforts to challenge higher quality NM400 steel grade products and more satisfactory services. Customer demand is our pursuit, and win customer satisfaction with quality. BBN after-sales team is responsible to solve the problem of technical support and quality, service complaints.