【作者】 周满春；

【导师】 刘相华； 刘战英；

【作者基本信息】 东北大学 ， 材料加工工程， 2009， 博士

【摘要】 高强度级别的钢板用于汽车制造是发展方向,采用高强度汽车大梁钢可以降低汽车的自重,屈服强度在500MPa以上级别的钢板成为重型汽车大梁用钢板的主流。本文为实现使用薄板坯生产高性能汽车大梁钢,对层流冷却的工艺与控制进行了模拟研究,通过计算机模拟层流冷却过程,优化了层流冷却工艺参数,提高了卷取温度的控制精度。根据模拟的工艺参数在实验室进行了轧制及冷却实验。通过试验,得到相应工艺下汽车大梁钢的组织及性能,进一步分析了工艺参数对组织性能的影响规律。同时利用有限元方法,对薄板坯连铸连轧生产线汽车大梁钢轧制过程的温度场进行了模拟,得出了薄板坯轧制过程温度场。为薄板坯连铸连轧汽车大梁钢生产工艺设计、改进和具体生产操作提供依据。1.在充分了解薄板坯连铸连轧生产线层流冷却控制的形式、特点及控制方法的基础上,采用VB语言编制了层流冷却模拟软件,利用该软件可以在改变带钢的轧制速度、厚度及冷却方式等工艺参数的情况下,自动确定带钢层流冷却时集管的开启总数及开启位置,输出卷取温度及冷却温降曲线等。2.在详细了解汽车大梁钢生产、应用及发展的前提下,对典型品种、规格汽车大梁钢T510L的层流冷却过程进行模拟,通过与现场实际数据的比较,模拟控制精度高,为准确控制卷取温度提供了依据。采用前段冷却方式,终轧温度在850±10℃时,卷取温度控制精度为600±10℃。能得到屈服强度为435MPa,抗拉强度为540MPa,延伸率为30%的强度高、韧性好的低碳汽车大梁钢。3.根据前述的模拟结果,在实验室中采用不同的轧制工艺及冷却策略,来验证模拟结果所得到的显微组织及力学性能,从而确定薄板坯轧制汽车大梁钢冷却策略、轧制工艺与组织性能的关系；研究了终轧温度、卷取温度、冷却速度及冷却方式对组织性能的影响规律。4.利用ANSYS有限元模拟软件,对使用薄板坯生产汽车大梁钢轧制过程的温度场进行了模拟,得到了薄板坯轧制过程中板带温度的变化规律,终轧后带钢边部比中部温度约低40℃,为轧制过程板型控制和轧后控冷提供了准确的温度数据。5.根据上述模拟和试验成果,2006年6月9日在唐山钢铁有限公司1810mm薄板坯连铸连轧生产线上进行了试生产,利用85mm连铸薄板坯,共生产2500吨汽车大梁钢,产品性能稳定,满足用户使用要求。通过对连铸薄板坯轧制汽车大梁钢控制冷却的模拟研究与试验,得到的控制冷却方式和参数用于生产实际,并对产品进行了组织性能分析。为准确控制卷取温度,提高汽车大梁钢的性能,优化了工艺控制参数,在实际生产中应用效果良好,2006年至2007年共计生产汽车大梁钢4.56万吨,产品性能稳定,满足使用要求。更多还原

【Abstract】 With the manufacture development of heavy vehicles, the existing strength-strip have been unable meet the need of cars. Using high-intensity beam can reduce self-weight of the automotive vehicles, the automobile beam steel with yield strength above 500MPa has become mainstream for heavy automobile. In this paper, to improve the performance of automobile steel girder, the mainly studies have been made:laminar cooling system with the process and control, based on the simulation of laminar cooling scene in computer to develop the control parameter of bending temperature.,gain the organization and performance of aumobile beam strip in homologise process performance,more analyze the influence regulation of technological parameter to structure property. Through finite element simulating to the rolling process of automobile beam strip by sheet sheet bar, get the temperature field of the process. It can provide data reference for process design and modify the parameters for rolling steel and produce the perfect quality steel of automobile frames.1. With the fully understanding of laminar cooling control modes of sheet bar continues casting and rolling line.Using VB language organized the simulation control software of the hot rolled strip laminar cooling, the software can be used to determine automatically the total number of open manifolds and the open positions in strip laminar cooling, to drew the curve of coiling temperature and cooling temperature drop by changing strip steel’s rolling speed, and the thickness and the cooling mode parameters.2. Base upon the undering of the production、utilization and development of automobile beam steel, simulated the typical grade and type automobile beam steel of T510L, comparing with the actual data that simulated temperature has high accuracy, it can provide the reference in accurately control strip’s bending temperature. Using front zone cooling mode, when finishing rolled temperature is about 850±10℃, the control accuracy of bending temperature is about 600±10℃. This cooling method will get the yield strength of 435 MPa and tensile strength of 540 MPa, elongation of 30% of the high-intensity, and good toughness of low-carbon automobile beam steel, which can satisfy the need of users. 3. Base above analog result,use different rolling process and cooling method in laboratory verify the microstructures and mechanical properties of analog result, confirm the relationship of cooling mathod、rolling process and microstructures.Researched the influence rule from finish rolling temperature、bending temperature cooling speed and cooling method to structure property.4. We can get the distribution and change regular of the temperature field in the thin slab rolling by simulating during the process of continuous casting and rolling in the automobile frames steel rolling production line using ANSYS software.The temperature of strip side low about 40℃than middle, provide the accuracy temperature date for profile control of rolling and cooling control after rolled.5. Using the result of simulate and test,we made the preproduction in Tang steel 1810mm thin bar continuous casting and rolling production lion on June 9 of 2006. The thick of the slab is 85mm,producted 2500 tons automobile beam strip,the product performance stabilization,meet the need of customer.This article is mainly directed against the car of steel girders of a series of research and simulation tests, in order to controlling batching temperature accurately,improve the mechanical properties and optimize the controlling parameter of the process, and has get a good effort in actual production, Stability performance of production, and meet the requirement of the use. Total produced automobile beam strip 45,600 tons at 2006 and 2007 years, the product performance stabilization,meet the need of customer.更多还原