NEW TECHNOLOGY FOR THE MANUFACTURE OF HIGH-COPPER, LOW-MANGANESE WEATHERING GRADE STEEL WITH TECHNOLOGICAL, ECONOMIC AND ENVIRONMENTAL ADVANTAGES

摘要

The present invention relates to a new steel technology based on the precipitation of copper sulphides instead of manganese sulphide (MnS), and presents new types of steel with economic, technological and environmental advantages. In short, these steels form two families. The first is that of ECOLOGICAL or GREEN STEELS, so-called because they can be produced from scrap which is highly contaminated with copper, preventing disposal of such scrap in nature. The second is that of COMINELLI or WEATHERING GRADE STEELS, which are high-copper and low-manganese steels with little or no manganese sulphide, and in which sulphur is stabilised by copper. In said steels, the high copper content imparts high corrosion resistance, and the copper sulphide improves mechanical properties (strain and impact resistance). The economic advantage results from the use of copper-contaminated scrap, the non-admixture of manganese and the absence of nickel, or even the elimination of the need to add nickel to control hot shortness during manufacture.