Tailored hot stamping and crash response of boron steels

该项目将解决超高强度汽车零部件的制造和碰撞响应问题，这些零部件具有通过热冲压硼钢制造的定制特性。热冲压钢是通过在冷却模具内在奥氏体（红热）条件下快速成形钢来制造的，冷却模具以足以引起马氏体相变的速率对材料进行淬火。使用这种加工路线可以实现超过1，500 MPa的强度，使得这些部件非常适合用于汽车内的防侵入结构碰撞安全部件，例如保险杠梁。车门防撞梁、A柱和B柱、车顶和侧轨。在最近完成的为期两年的NSERC-CRD项目中，当前项目团队的先前工作已经成功地开发了具有定制特性的“实验室规模”B柱。使用分段式模具，将各个模具段选择性加热至高达400 ℃，从而允许在热冲压期间局部控制淬火速率，从而控制所形成的部件内的局部性质。这种定制的部件是汽车行业内相当感兴趣的主题，因为它们将使部件具有局部高强度区域以防止碰撞期间的侵入，但具有可被设计成提供一些能量吸收能力的较软区域。这个拟议的加拿大汽车合作项目将从之前的CRD项目中汲取经验，开发具有优化能量吸收特性的定制热冲压组件。该项目将以实验和分析研究为特色，作为定制热冲压加工路线的概念证明。APC项目活动将集中于多区域热冲压模具的开发，该模具将生产适于在侧面碰撞和轴向挤压载荷下进行机械测试和性能评估的热冲压部件。优化技术将与热冲压的有限元模拟相结合，为我们的工业合作伙伴提供部件和工艺设计工具，以开发高性能的结构碰撞部件。优化研究的输出将通过制造多区域热冲压模具进行验证，以生产适用于冲击测试的组件级多区域热冲压。冲击测试将用于评估冲击性能，特别是识别部件的硬马氏体区和软贝氏体区之间的过渡区中的任何问题。

This project will address the fabrication and crash response of ultra-high strength automotive components with tailored properties fabricated through hot stamping of boron steels. Hot stamped steels are fabricated by rapidly forming steels in the austenitic (red hot) condition within cooled dies that quench the material at a rate sufficient to cause a martensitic phase transformation. Strengths in excess of 1,500 MPa can be achieved using this processing route making these components highly desirable for use in anti-intrusion structural crash safety components within automobiles such as bumper beams. door intrusion beams, A- and B-pillars, roof and side rails. Previous work by the current project team within a recently completed two-year NSERC-CRD project has been successful in developing a "laboratory-scale" B-pillar with tailored properties. A segmented die was used with selective heating of individual die segments up to 400"C thereby allowing local control of quench rates during hot stamping with resulting control over the local properties within the as-formed part. Such tailored parts are the subject of considerable interest within the automotive sector since they will enable components with local high strength regions to prevent intrusion during crash, but with softer regions that can be designed to provide some energy absorption capabilities. This proposed Automotive Partnership Canada project will pick up from the previous CRD project to develop a tailored hot stamped component with optimized energy absorption characteristics. This project will feature experimental and analytical research that will serve as proof of concept of the tailored hot stamping processing route. The APC project activity will centre on the development of a multi-zone hot stamping die that will produce a hot stamped component suitable for mechanical testing and performance evaluation under both side impact and axial crush load cased. Optimization techniques will be developed in conjunction with finite element simulation of hot stamping to provide component and process design tools for use by out industrial partners to develop high performance structural crash components. The output of the optimization study will be validated through fabrication of a multi-zone hot stamping die to produce a component-scale multi-zone hot stamping suitable for impact testing. The impact tests will serve to assess the impact performance, in particular, identifying any issues in the transition zone between the hard martensitic zone and the softer bainitic zone of the part.