Research On Temperature Field Of Hot-forming Heating Device By Numerical Simulation

Applications of high-strength stamping parts by hot-forming technology in the automotive vehicle bodies can achieve improve vehicles safety and lighter the weight at the same time to meet the increasingly stringent automotive crash-safety and emission standards requirements.In recent years,the hot-forming technology is more and more popular with vehicle manufacturers.The hot-forming technology is just for high-strength steels which have good hardenability,such as 22MnB5 and 30MnB.At room temperature,the strength of high-strength steel is about 500～600MPa,after the hot-forming,the strength can reach 1500MPa.The stamping parts which used hot-forming technology are light weight,high strength,high precision,good forming quality,no rebound,and are used in the higher strength parts,such as A pillar,B pillar,door crash beams,front and rear bumper and so on.In foreign countries,the hot-forming technology has been widely used.In china,hot-forming technology has just begun,make major research on heat-forming process and hot-forming mold,less research on hot-forming heating device and its numerical simulation.In the hot-forming process,heating the sheet is a very important aspect,the heating device is a core equipment in hot-forming production line.Heating temperature and temperature distribution affect the heated products' performance and determines the quality of hot-forming stamping parts.If the heating temperature is too high,sheet will burn-off and easily be cracked when quenching,waste the steel.If the heating temperature is too low,sheet will can't obtain austenite,which affect the quality of hot-forming stamping parts.If the temperature field is not uniform will affect the uniform of sheet' temperature.The heating quality can be guaranteed when the heating temperature is appropriate and the temperature field is uniform.At present.we don't have heating device for high-strength steel'hot-forming.In order to meet the domestic automotive industry' need of high strength steel' hot stamping parts,the hot-forming heating device has been designed and simulated in this article.At present,the hot-forming heating devices have two types,including roller heating devices and step-by-step heating device.In order to save production costs,improve energy efficiency,heating device to ensure productivity and product quality,this hot-forming heating device is roller heating device,which designed to burn natural gas and be controlled at nitrogen-based atmosphere,this heating device has low labor intensity,high degree of mechanization and automation,low environmental pollution and so on.According to the technical requirements and production needs,designed the overall structure of hot-forming technology' heating device,reasonable layout the transmission components,heating elements and gas pipelines,ect.Designed heating device' critical systems,such as roller bearing structure with the furnace,combustion, heating elements and so on.Calculated heat-related parameters,such as heat transfer and thickness of lining,fuel combustion and heating device'power.Combine of numerical simulation respectively simulate the temperature field of the furnace and lining' temperature field.Established the finite element model of furnace in ANSYS' CFD analysis module,applied loads and constraints,then solve it.According the simulation results of furnace temperature,to optimize the structure of heating device,determine this heating device is 27 radiant tube(hot zone radiant tube' interval is 1m).Simulated the heating device' heating process,with this structure,optimize the heating time,the heating time is 6840s.Simulated the temperature field of the lining in THERMAL module.According the lining' simulation temperature field to verify the design is correct.This lining' heat elimination is very less,the heating device has less heat loss,can rapid warming,meet the technological' requirements.By simulating the hot-forming heating device' temperature field,to optimize the heating device' structure and heating parameters,to verify the correctness of design.By designing and simulating the hot-forming technology' heating device to make a preparation for establishing a complete production line of hot-forming,to fill the domestic hot-forming heating device' blank,to make possible for obtaining good performance of high-strength steel' hot stamping parts and to promote the commercial of hot-forming' high-strength stamping parts,in order to accumulate valuable experience for further study and numerical simulation techniques.