Development of slow-corrosion steel in the system Fe-Cr-Mn-N-Cu for typical automotive application

  Microstructure of the developed alloy Copyright: © IEHK Microstructure of the developed alloy

In cooperation with Outokumpu Nirosta GmbH, an alloy concept for a manganese steel containing chromium and nitrogen is being developed in the transfer project T05 within SFB-761, which is optimized for typical automotive applications. The use of steel from the electric arc furnace with 100% raw material input from steel scrap from the automotive industry, which has an increased copper content, is planned. Special attention is paid to the mechanical and corrosive properties, which are set by the alloy design in the Fe-Cr-Mn-Cu-(C,N) system.

 

The challenge of the project lies on the one hand in ensuring continuous castability, which is negatively influenced by manganese and chromium, thus making it necessary to reduce the alloy content. On the other hand, a high yield strength, tensile strength and 40% total elongation are to be achieved. In addition to the mechanical properties, sufficient corrosion resistance and the ability to withstand intergranular corrosion must be ensured. Within the scope of the cooperative project, the mechanical and corrosive properties of the developed alloys are therefore being investigated and continuous casting tests are being carried out on a pilot plant on an industrial scale.