Protective metal coating
Purpose and goal
A pre-treatment of uncoated boron steel has been investigated, which after hot stamping results in the formation of an oxide showing excellent adhesion to the steel. The objective has been to build up an understanding of the process, optimize, and implement it. The effect of the pre-treatment has been verified and knowledge has been acquired about how the process improves the oxide adhesion. Small variations in the incoming material affect the process window, which has made implementation more difficult than anticipated.
Results and expected effects
The performed research has resulted in an increased understanding of the oxide growth during press-hardening and the factors influencing scale adhesion, not only in the suggested process but also in the standard process. The acquired knowledge is anticipated to enable the development of a stable process where subsequent shot-blasting can be eliminated.
Approach and implementation
The project has been carried out in close collaboration between Gestamp HardTech AB, Swerea MEFOS and Luleå University of Technology (LTU). Material showing different degree of scale adhesion has been produced both in lab- and pilot scale, and this material has been investigated, tested, and characterized in order to understand what factors influence the oxide adhesion. The collaboration has been successful, where all project partners have contributed in supplementary ways and the people involved have gained much knowledge along the way.