The hot rolling technolodge of EN steel grade S420NL material

With the development of API5L-B pipeline steel plate technology and the advancement of welded pipe forming and welding technology, the application scope of pipeline welded pipe is gradually expanding, especially the advantages of welded pipe in the range of large-diameter group spacing are more obvious. In 2004, the output of API5L-B (L245) seamless line pipe was about 400,000 tons. The steel grade includes X42-70, EN steel grade S420NL material, and the varieties include onshore line pipe and subsea line pipe.

Our company was founded in 2000, which initially committed to providing high-quality steel EN steel grade S420NL material products for China's rapid infrastructure construction. With the advantages of steel resources and good reputation in the domestic market, combined with the huge demand for steel in the international market, we began to export EN steel grade S420NL material steel to the international market, opening up the international steel market.

No. 45 steel is commonly used medium carbon quenched and tempered structural steel. The cold plasticity of No. 45 steel is generally better than EN steel grade S420NL material. Annealing and normalizing are better than quenching and tempering. No. 45 steel has higher strength and better machinability than Q345 steel. After proper heat treatment, it can obtain certain toughness, plasticity and wear resistance. No. 45 steel EN steel grade S420NL material is suitable for hydrogen welding and argon arc welding, but not suitable for gas welding. Preheating is required before welding, and stress relief annealing shall be conducted after welding.

Low alloy high strength steel is a kind of engineering structural steel developed by adding a small amount of Mn, Si and a small amount of Nb, V, Ti, Al and other alloy elements on the basis of carbon structural steel, EN steel grade S420NL material. The so-called low alloy means that the total amount of alloying elements in steel is less than 3%. High strength is relative to carbon engineering structural steel. The development principle of low alloy high strength steel is to use as few alloy elements as possible to obtain as high comprehensive mechanical properties as possible, so as to meet the requirements of use and low cost.

After-sales service team is a key department to test the steel quality. Product quality is always the foundation of our survival and development. The company's full inspection from raw materials to finished products; and implements standardized, scientific, and strict internal quality control and management systems in accordance with the process flow during the production process; products can only leave the factory if qualified, and follow-up problem solving systems are implemented in after-sales services to guarantee the customers’ interest.