Precipitation Strengthening of Nanoscale Cementite in 0.17 Carbon Steel During Ultra Fast Cooling (UFC)

摘要

With the resource crisis going more and more severe, Steel industries are currently facing the challenge of reducing alloy costs in steel products, which negatively impacts the strength of steels. In order to meet the requirements of reduction in alloy cost and maintain strength, cementite in steels is viewed as a viable option to replace microalloying precipitates because it is a common second phase constituent in steels, and if cementites can be effectively refined to the scale of a few nanometers, they can induce significant precipitation strengthening effect to effectively substitute in part the strengthening contribution provided by the precipitates of microalloying elements. In recent years, there has been a lot of research work on the refinement of cementites, however, given that cementites are usually to form lamellar pearlite structure and generally tend to coarsen at relatively high temperatures, little work has been carried out to generate nanoscale cementites in the carbon steels by controlling the cooling paths after hot rolling.