Advanced processing for recycling of iron scrap with impurities

The present research focuses on the recycling of steel in combination with copper or aluminum alloys. To use iron scrap with a copper content in the range of 0.5 to 15%, a water atomization process was carried out, producing a rapidly solidified powder with copper of nano-order size dispersed in it. The powder was then hot rolled in the 600°C to 1000°C temperature region, where there is no liquid phase of copper, to produce a solid body. The solid bodies obtained presented a porosity of less than 1% for all the values of temperature and copper concentration, and it was established that the proposed process can be used for a wide range of concentrations of metallic impurities. The tensile strength increased with the copper content for all the temperatures, reaching stability at a copper concentration over 5%. Rapidly solidified powder was annealed and compacted at 600°C, resulting in a reduction of strength compared to non-annealed powder. The microstructure with a finely dispersed copper content seemed to have a considerable effect on the tensile strength of the compacted bodies. In the case of the use of aluminum-containing iron scrap, the results show that addition of aluminum to cast iron increased the resistance to abrasion, the high temperature oxidation characteristics, and the vibration control characteristics. When this cast iron was kept in air at temperatures ranging from 800°C to 1000°C, it was observed that the graphite on the surface was substituted by alumina.