Research And Development Of Fine Grain Steel In High-speed Wire Rod Line Of Dazhou Steel Group

The fine grain hot rolled rebar is mainly used as the structure framework of high-rise buildings.Since the Wenchuan earthquake in 2008,The architectural framework to improve seismic effect of longitudinal reinforcement,stirrup put forward higher requirements.In order to meet the needs of market competition,expand variety specifications,and to upgrade the product,Dazhou steel group advanced a development plan of HRBF500 E high-speed wire rod which is of strategic and realistic significance for steel survival and development.This paper provided a comprehensive analysis and evaluation of steel line process equipment level,and argued that Dazhou steel group holds the potential for developing the ? 12 HRBF500 E fine grained plate steel.Consequentially,the development of the ?12 HRBF500 E product could provide technical support for the research and development of seismic reinforcement of higher level and of more specifications.Based on the national standard,the internal control standards of HRBF500 E steel components were developed,taking account of the actual production conditions and experiences.To ensure the smooth progress of the development of the ? 12 HRBF500 E product,a special finish rolling and reduce sizing pass system was designed and a rolling schedule was made.After examining all the main motors' overload capacity,it revealed that 7 #,9 #,10 #,11 # and 12 # mill load were slightly overloaded.So this a few mill type of workpiece material was optimized,which led to a reasonable distribution of motor load,thus guaranteeing a smooth process of the product.Through small-scale experiments,it found that the best spinning temperature was 770 ~ 790 ?,and when 9 typhoon machines are opened,steel organization and performance stability could be achieved.After preparing the controlled rolling and cooling plan for the ?12 HRBF500 E fine grained steel wire rod,and conducting industrial production trials,GB/T1499.2-2007 requirements for the reinforcement of various performance indicators have been met.The results of aging sensitivity test showed that the ?12 HRBF500 E fine grained steel has the characteristics of low aging sensitivity,which could shorten the delivery cycle,thus avoiding a large backlog of products.The welding test results showed that the microstructure of the fine grain reinforced steel weld was reticular ferrite and bainite and pearlite,Because of the strengthening effect of bainitic tissue,the performance of bainitic structure has no obvious decrease and it has good welding performance.