Research And Development For Steel Strand Of 70 Steel

The steel strand wire is a product made of multi-strand wire,which is used for the galvanizing steel strand of overhead conductor,the prestressed steel strand of the bridge,the galvanized steel strand of the cable reinforced.Steel not only requires high strength,but AlSo elongation and toughness;As in the production of steel wire strands of rope parent metal at the same time AlSo requires good hot rolled wire rod surface quality and dimension,cleaning rod stable performance,less decarburization,give priority to with sorbite microstructure,there is no martensite,bainite and other organizations.This article mainly Japanese standard 70 steel as the research object,through the steelmaking process(initial smelting,refining,continuous casting process,heating process,cold rolling mill control controlled rolling,steyr air-cooled control to control the whole flow;At the same time focus on analysis of sorbite rate,center segregation,surface decarburization,surface oxidation and the influence of spinning temperature on austenite grain size,and the influence of process parameters on mechanical properties and mechanical properties of the lap and not take it,pushing the head and tail performance differences,such as 70 steel wire drawing fracture analysis.Specific research contents and results are as follows:(1)analysis of the chemical composition of the original 70 steel production process and control of steelmaking,continuous casting process,heating process,the rolling process,cooling control technology parameters,find the problems existing in the targeted optimization,a new experimental scheme and experimental study on the analysis.(2)optimize the production of 70 steel rods,which meet the standard requirements for the production of steel mechanical properties and process performance,and meet the requirements of users;The soxite group of steel has an average of more than 90%.The qualified rate of casting billet was more than 99.0%,the steel qualified rate was greater than 99.0%,and the yield was greater than 95.0%.(3)steelmaking process precision chemical composition control,reduce the influence on wire rod mechanical properties and process performance,especially for the residual element such As Cu,As,Sn in steel control,reduce the effect on the properties of wire rod drawing.The solidification process of continuous casting is controlled by the solidification process of continuous casting billet,which can control the solidification of internal crack,hole,center loose and center segregation.The surface quality of the billet is controlled,and its effect on the surface quality of the rod is eliminated.(4)the influence of the size of the surface oxidation and decarbonization of billet on the structure and grain size of the steel billet is studied.Control of cooling open rolling temperature,inlet temperature,TMB BGV inlet temperature,spinning temperature of steel structure,mechanical properties,process performance of homogeneous and stable,the temperature range for narrowband control.Adopt standard type control cooling process after rolling.