Production Process And Microstructure Properties Of Large Width And High Strength Angle Steel

Heavy Section Steel production line of Tangshan Iron and Steel Company put into productionin March 2013,and the main production is large size high strength and lowtemperature impact resistance angle steel.The deformation resistance,and the influence for organization performance of rolling technology are studied,and pass system has been optimized,put forward process parameters and technical procedures suitable for actual production requirement,the manufacture organization performance of the products have been characterized,further optimized the production process parameters.The microstructure and mechanical properties of large angle steel have been studied by optical microscope(OM),scanning electron microscope(SEM),tensile test and impact test.The following conclusions have been obtained.The plastic deformation resistance of V-N microalloyed Q420 B large angle steel has been studied by thermal simulation experiment,and the mathematical model of deformation resistance of Q420 B large angle steel has been established.The Q420 and Q460 large-size angle of the hole system has been designed.The angle steel better than the national standard series of 22#,25#,28#,30# Q420 and Q460 has been successfully developed.The product surface has high precision,which according to the State Grid Corporation of technology to develop the 25# 22 mm,25mm thickness specifications and 28#,30# 20-35 mm thickness specifications of the angle.The results show that the chemical composition,production process,microstructure and properties of Q420 and Q460 large-size low-temperature impact angle steel are influenced by each other,and the key system of smelting,continuous casting,rolling correcting and straighting is formed.According to the research results and combining with the actual production condition,heating temperature of the test steel needs to control in 1150~1250? and heat preservation.In order to ensure the finishing temperature,and to consider the temperature drop of the rolling process,rolling temperature is 1000 ~ 1050?,and finishing temperature is 790 ~ 850?.