Research On Key Technology Of Tailored Thermoforming Heating Furnace For High Strength Steel Plate

Automobile lightweight is a major trend in the development of automotive industry.Hot forming and tailored properties hot forming of high strength steel plate,which combines light weight and safety of automobiles,are one of the most successful and fastest-developing automotive steel technologies.With the increasing proportion of hot forming parts and tailored properties hot forming parts in automobiles,hot forming parts have gradually become diversified and complicated,and the existing thermoforming heating equipment can no longer meet the requirements of its production process,which puts forward higher requirements for hot forming heating equipment.In this context,the key technologies of high strength steel thermoforming furnace,including a new type of tailored properties hot forming process that can be realized in the furnace,are studied in this paper.In this paper,the roller hearth heating furnace for hot forming of ultra-high strength steel plate,which is independently developed,is taken as the research object,and its key technologies are studied:1.Most of the high strength steel plates for automobiles are thin plates with a thickness of 0.7-3.0 mm.Once they are heated unevenly,they are easily deformed,which is extremely unfavorable for the subsequent forming and quenching of the plates.Therefore,the uniformity of the furnace temperature is required.In this paper,the heat exchange affecting the uniformity of temperature field inside the furnace are analyzed,the main factors affecting the uniformity of temperature field in the furnace are determined,the finite element model of temperature field simulation is established,and the heating process is simulated according to different distribution schemes of radiating tubes.2.The multi-gradient temperature control process of roller hearth furnace is studied.According to different specifications of sheet metal,there are different requirements for the heating process in the furnace.Taking Al-Si coated plate as an example,the temperature curves of different specifications of the plate under the general heating process and the multi-gradient control are studied by combining numerical simulation with experimental verification.The feasibility of multi-gradient temperature control process was determined and the multi-gradient temperature control process for plate with different specifications was provided as a reference.3.A new type of tailored properties hot forming process that can be implemented in the furnace is studied.A new type of tailored properties hot forming process was designed,and a "experimental platform of district air-cooling for high strength steel plate" was built.The experimental study on the new tailored properties hot forming process was carried out.It was determined that the new process could meet the demand of tailored properties of parts,and the length of the transition region was about 40 mm.