Shouqin Company 690MPa Highyield Strength Steel Technology

With development of the comprehensive mining machinery and increase of the security facilities, coal machinery with big power and high performance is required; Besides, its strength and wear resistance performance are also improved. The steel grade about the Coal mine hydraulic support was turned into Q550 from Q460(even Q690). As an important structural material, high strength low alloy steel has high strength, low ductility brittleness transition temperature and good elongation.With high strength steel production experience of the domestic and the foreign Compared, chemical Composition Requirements of high strength steel components and effect of various elements on the mechanical properties, Shouqin company equipment characteristics analyzed, steel smelting, rolling,cooling and heat treatment process considered, we use UFC+ACC water-cooling model to formulate the feasibility of the Quenching and tempering process, S690 QL Q690D components system and process was determined.Conclusion:By the reasonable composition design,rolling and heating treatment process, the microstructure and performance of S690 QL and Q690 D is good., in line with the standard product meet customer demand; At the same time, combined with the actual performance results, according tothe plate energy rich index, in the existing component system based on, corresponding to different thickness group distance, further optimization and adjustment of Cr, Ni, Mo, Nb, V alloy content, to achieve the precise control of the composition, further reducing the cost. Improve the market competitiveness of the products, and provide a train of thought and direction for the development of other varieties of steel.