Advanced zn-coated steel development and manufacturing technology for automotive weight reduction and safety enhancement

提高汽车燃油效率，从而减少有害排放的最有效手段之一是减轻车辆重量。这可以通过在结构部件和车身封闭件中增加使用高级高强度钢（AHSS）来实现。车辆安全性至关重要，超高强度（UHSS）压力硬化钢（PHS）中与安全相关的成分比例越来越高。在这些关键应用中使用UHSS和AHSS允许使用更薄的钢板横截面，同时提高乘客安全性。然而，减少金属板厚度需要增强的腐蚀保护以保持结构完整性并满足消费者的耐久性期望，为此，通过连续镀锌（CGL）工艺施加的锌基涂层是实现这一目标的具有成本效益的手段。该项目将专注于开发下一代AHSS -第三代（3G）AHSS -其合金化程度高于当前一代AHSS，但在不牺牲成形性的情况下具有更高的强度。然而，3G AHSS的合金含量较高，要求它们专门设计为与CGL工艺兼容，以确保实现所需的性能，同时允许形成防腐蚀的锌基涂层;这是CRD的目标之一。此外，当前一代PHS与用于腐蚀保护的Zn基涂层不兼容，并且下一代Zn涂覆PHS的开发也是CRD的主要目标之一。最后，但并非最不重要的是，用于克服在CGL中加工AHSS的困难的加工技术可能会导致关键的点焊制造工艺出现问题。出于这个原因，本CRD的最后一个目标是系统地确定AHSS处理替代品对点焊工艺的影响。该项目将为加拿大汽车和钢铁行业培训10名学生，并将为这两个行业提供一套工具，用于提高他们在高要求汽车行业的竞争优势。

One of the most effective means of increasing automotive fuel efficiency and, thereby, decreasing harmful emissions is vehicle weight reduction. This can be accomplished by increasing the use of advanced high strength steels (AHSS) for structural components and body closures. Vehicle safety is of paramount importance, for which ultra-high strength (UHSS) press-hardening steels (PHS) are comprising increased proportions of safety-related components. The use of UHSS and AHSS in these critical applications permits the use of thinner sheet steel cross-sections while enhancing passenger safety. However, reducing sheet metal thickness demands enhanced corrosion protection to maintain the structural integrity and meet consumer durability expectations, for which Zn-based coatings applied by the continuous galvanizing (CGL) process is a cost-effective means of achieving this objective. This project will focus on developing the next generation of AHSS - third generation (3G) AHSS - which are more highly alloyed than the present generation of AHSS, but have significantly higher strengths without sacrificing formability. However, the higher alloy contents of 3G AHSS require that they be specifically designed to be compatible with the CGL process to ensure that the desired properties be achieved while allowing for the formation of corrosion protective Zn-based coatings; this is one of the objectives of the CRD. Also, the current generation of PHS are not compatible with Zn-based coatings for corrosion protection and the development of the next generation of Zn-coated PHS is also one of the primary objectives of the CRD. Last, but not least, the processing techniques used to overcome the difficulties of processing AHSS in the CGL can cause problems with the critical spot welding fabrication process. For this reason, the last objective of this CRD is to systematically determine the effect of AHSS processing alternatives on the spot welding process. This project will train ten students for the Canadian automotive and steel industries and will provide the both industries with a set of tools which can be used to increase their competitive advantage in the highly demanding automotive sector.