Effective of Surface Active Elements on the Selective Oxidation of Fe-Mn and Fe-Si Alloys

为减少交通部门温室气体排放而提高车辆燃油效率的立法要求正在推动汽车制造商减轻车辆重量，同时保持车辆的安全性和耐用性。为了实现这一目标，制造商在设计中使用越来越多的先进高强度钢，以提高材料的比强度并减少材料的横截面。然而，减少横截面的使用增加了对钢材防腐的需求，以保持车辆的完整性、安全性并满足消费者对耐用性的期望。采用连续镀锌(CGL)工艺的锌基金属涂层是实现这一目标的最经济有效的手段。然而，最新牌号的先进钢具有更高的合金含量，这使得CGL工艺中的合金元素--主要是锰(Mn)和硅(Si)--选择性氧化，使反应润湿和涂层附着力变得困难。有几种方法可以克服这一困难，使用内氧化-在衬底内部形成有害氧化物，留下良好的表面-以及使用表面活性元素，如少量添加锡(锡)，或两者的组合，麦克德米德研究小组目前正在为下一代高合金化高级钢进行研究。本提案旨在解决下一代先进钢中主要合金化元素--锰和硅--对表面活性合金化添加效果的影响这一根本问题，特别是在改变外部氧化物形态以使衬底与CGL工艺兼容的过程中，尤其是添加锡。这项调查的结果将与麦克德米德在设计下一代先进钢材方面的其他活动相结合，使其既能与连续镀锌工艺兼容，又能满足汽车材料行业日益苛刻的性能目标。该项目将培训两名博士水平的研究人员，他们将拥有表面和性能导向型钢设计的高级知识，这将有助于加拿大制造商生产更轻、更安全、可持续、省油的汽车，这将有助于促进未来以知识为基础和可持续的制造业。

The legislative requirements for increased vehicle fuel efficiency in order to decrease transportation sector greenhouse gas emissions is driving automotive manufactures to reduce vehicle weight while maintaining vehicle safety and durability. To achieve this goal, manufacturers are employing increasing amounts of advanced high strength steels in their designs such that material specific strength can be increased and material cross-sections reduced. However, the use of reduced cross-sections increases the need for corrosion protection of the steels in order to maintain vehicle integrity, safety and meet consumer durability expectations. Zinc (Zn)-based metallic coatings applied by the continuous galvanizing (CGL) process is the most cost effective means of achieving this goal. However, the newest grades of advanced steels have higher alloy contents, which make the process of reactive wetting and strong coating adherence difficult due to alloy element - mainly manganese (Mn) and silicon (Si) - selective oxidation in the CGL process. There are several means of overcoming this difficulty, with the use of internal oxidation - in which harmful oxides are formed inside the substrate, leaving a good surface - and the use of surface active elements, such as small additions of tin (Sn), or combinations of the two, being currently under investigation by the McDermid research group for the next generation of highly alloyed advanced steels. The present proposal seeks to address the fundamental question of the effect of the primary alloying elements in the next generation of advanced steels - Mn and Si - on the efficacy of surface active alloying additions, in particular Sn, in altering the external oxides morphology such that the substrates are compatible with the CGL process. The findings of this investigation will be leveraged with McDermid's other activities on the design of the next generation of advanced steels such that they are both compatible with the continuous galvanizing process and meet the increasingly demanding property targets of the automotive materials sector. This project will train two PhD level researchers who will have advanced knowledge of surface and property oriented steel designs, and which will help enable Canadian manufacturers to produce lighter, safer, sustainable, fuel efficient vehicles and which will help promote the knowledge-based and sustainable manufacturing sector of the future.