Abstract
It is generally believed that phosphorus in steel is a harmful impurity that increases the tendency of steel to brittle fracture at subzero temperatures. In this paper the effect of phosphorus on the mechanical properties of sheet rolled from low-carbon steel grade 10XSND was studied. The results of impact toughness evaluation (by KCU method at -60°C) of sheet rolled products of different thicknesses were taken for the study. For the most accurate results were taken the lowest, average and highest values (from the obtained interval) of impact toughness for metal sheets with thickness from 10 to 32 mm. It was found that the effect of phosphorus on impact toughness is determined by the thickness of sheet metal. At thickness of rolled sheet up to 20 mm positive dynamics of impact toughness is observed with increase of phosphorus content up to 0,011-0,013%. For rolled products with a thickness of more than 20 mm, the effect of phosphorus on the impact strength of sheet metal is negative. Recommendations on optimal phosphorus content in rolled products from low-carbon steel grades are given, as well as the forecast of changes in steelmaking indicators on the example of electric arc furnace (EAF).
Keywords:
sheet metal, sheet metal thickness, phosphorus content, impact toughness.