超高强钢B1500HS热成形关键工艺参数实验研究

发布时间：2018-02-09 12:45

本文关键词： 热成形奥氏体化加热温度保温时间初始成形温度冷却速率　出处：《江苏大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着国际石油价格不断上涨以及“节能减排”概念的提出,整个社会对汽车轻量化有着迫切需求。热成形工艺生产的超高强钢制件在保证车辆安全性能的同时能够很好的实现轻量化的要求,因此热成形技术成为缓解能源危机、减少环境污染和实现节能减排的有效途径。热成形技术是指将超高强钢板加热到奥氏体化温度并保温一段时间后,快速转移到带有冷却水道的热冲压模具中进行成形和保压淬火,成形后零件获得完全马氏体组织,其抗拉强度达到1500MPa以上,在保证安全性的情况下大大减轻了制件的重量。热成形过程中工艺参数的合理设计能够有效的提高零件力学性能和消除零部件厚度分布差异过大、起皱、开裂、回弹等成形缺陷,保证冲压件质量的合格率和稳定性。因此,为了热成形后能够获得高质量的零部件,需要对热成形关键工艺参数进行优化研究。热成形中涉及的关键工艺参数包括:加热工艺参数、冲压工艺参数和保压淬火工艺参数。本文主要研究内容如下:1)超高强钢B1500HS加热工艺参数(奥氏体化加热温度和保温时间)实验研究。研究了奥氏体化加热温度和保温时间对超高强钢板淬火后抗拉强度、硬度及微观组织的影响规律,研究结果表明:当奥氏体化加热温度为910℃,保温时间为4min时,采用模具淬火后的板料获得均匀的板条状马氏体组织,具有最佳的机械性能。2)超高强钢B1500HS冲压工艺参数(初始成形温度)实验研究。分别研究了初始成形温度对超高强钢板极限拉深比(LDR)和杯突值(IE)的影响规律,同时研究了初始成形温度对超高强钢板淬火后抗拉强度、硬度及微观组织的影响规律。研究结果表明:当初始成形温度为700℃时,超高强钢板具有最佳的成形性能,并且淬火后的机械性能满足实际热成形生产要求。3)超高强钢B1500HS淬火工艺参数(淬火冷却速率)实验研究。利用搭建的温控系统平台探究了连续热成形过程中板料淬火冷却速率与冷却水流量之间的关系,研究了淬火冷却速率对超高强钢板淬火后抗拉强度、硬度及微观组织的影响规律,确定了合理的淬火冷却速率为43.09~45.3℃/s。
[Abstract]:With the continuous rise in international oil prices and put forward "energy-saving emission reduction" concept, the whole society has urgent demand for lightweight cars. Production process of hot forming of ultra high strength steel to ensure the vehicle safety performance and can achieve good lightweight requirements, therefore become the hot forming technology to alleviate the energy crisis, reduce environmental pollution and the effective way to realize energy saving and emission reduction. Hot forming technology refers to ultra high strength steel is heated to the austenitizing temperature and holding time, quickly transferred to the hot stamping die with cooling channels in the form and the pressurequenching, after forming fully martensitic microstructure, the tensile strength reached more than 1500MPa. To ensure the security situation greatly reduces the weight of the parts. The reasonable design of hot forming process parameters can improve the mechanical properties effectively and eliminate Different parts of the thickness distribution is too large, wrinkling, cracking, springback of forming defects, ensure the qualified rate and stability of the stamping quality. Therefore, in order to hot forming can be obtained after high quality parts, need to optimize the key parameters of hot forming. Hot forming to the key process parameters include heating process parameters. The stamping process parameters and the pressurequenching parameters. The main research contents of this paper are as follows: 1) B1500HS ultra high strength steel heating process parameters (austenitizing temperature and holding time). Experimental study on the effects of austenitizing heating temperature and holding time on the tensile strength of ultra high strength steel after quenching, influence of hardness and microstructure of the research the results show that when the austenitizing temperature is 910 DEG C, the holding time is 4min, obtain lath martensite microstructure by sheet die after quenching, with the most The mechanical properties of.2 ultra high strength steel B1500HS) good stamping process parameters (initial deformation temperature) were studied experimentally. The initial forming temperature of ultra high strength steel plate limit drawing ratio (LDR) and cupping value (IE) were investigated, and the effect of the initial forming temperature on the tensile strength of ultra high strength steel after quenching effect the law of the hardness and microstructure. The results show that: when the initial forming temperature is 700 degrees centigrade, ultra high strength steel plate forming has the best performance, and the mechanical properties after quenching meet the actual production requirements of hot forming.3) ultra high strength quenching process parameters of B1500HS steel (cooling rate). Experimental study explores the continuous hot forming process in the sheet the relationship between cooling rate and cooling water flow using temperature control system of the platform, studied the quenching rate on tensile strength of ultra high strength steel after quenching, hardness and microstructure The reasonable cooling rate of quenching is 43.09~45.3 C /s.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG306;TG156.3

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