The process of press hardening is gaining importance in view of the increasing demand for weight reduction combined with higher crash safety in cars. An alternative to the established manganese-boron steel 22MnB5 is hot-formed martensitic chromium steels such as AISI 420C. Strengths of 1850 MPa and elongations of 12% are possible, exceeding those of 22MnB5. In industrial manufacturing, FE-simulation is commonly used in order to design car body parts cost-efficiently. Therefore, the characterization and the modeling of AISI 420C regarding flow stress, phase transformations as well as failure behavior are presented in this paper. Temperature-depended flow curves are determined, showing the low flow stress and hardening behavior at temperatures around 1000 °C. Cooling experiments are carried out, and a continuous cooling diagram is generated. Observed phases are martensite and retained austenite for industrial relevant cooling rates above 10 K/s. In addition, tests to investigate temperature-dependent forming limit curves are performed. As expected, the highest forming limit is reached at 1050 °C and decreases with falling temperature. Finally, a simulation model of a press-hardening process chain is set up based on the material behavior characterized earlier and compared to experimental values. The forming force, phase transformation and forming limit could be calculated with good agreement to the experiment.

鉴于对汽车减重和更高碰撞安全性的需求不断增加，冲压硬化工艺变得越来越重要。已建立的锰硼钢 22MnB5 的替代品是热成型马氏体铬钢，例如 AISI 420C。1850 MPa 的强度和 12% 的伸长率是可能的，超过 22MnB5。在工业制造中，有限元模拟通常用于以经济高效的方式设计车身零件。因此，本文介绍了 AISI 420C 在流动应力、相变和失效行为方面的表征和建模。确定了与温度相关的流动曲线，显示了在 1000 °C 左右的温度下的低流动应力和硬化行为。进行冷却实验，生成连续冷却图。对于高于 10 K/s 的工业相关冷却速率，观察到的相是马氏体和残余奥氏体。此外，还进行了研究温度相关成形极限曲线的测试。正如预期的那样，最高成型极限在 1050 °C 时达到，并随着温度的下降而降低。最后，基于较早表征的材料行为并与实验值进行比较，建立了冲压硬化工艺链的仿真模型。计算出的成形力、相变和成形极限与实验吻合良好。最高成型极限在 1050 °C 时达到，并随着温度的下降而降低。最后，基于较早表征的材料行为并与实验值进行比较，建立了冲压硬化工艺链的仿真模型。计算出的成形力、相变和成形极限与实验吻合良好。最高成型极限在 1050 °C 时达到，并随着温度的下降而降低。最后，基于较早表征的材料行为并与实验值进行比较，建立了冲压硬化工艺链的仿真模型。计算出的成形力、相变和成形极限与实验吻合良好。