耐低温冲击韧性球墨铸铁的研制OA

Impact toughness refers to the ability of a material to absorb plastic deformation work prior to fracture under impact loading,which reflects the material's tendency to brittle fracture.The higher the impact absorbed energy,the lower the possibility of the material undergoing brittle fracture.Ductile iron is prone to appear brittle fracture when subjected to impact load at low temperatures.In order to improve the application range of ductile iron,it is necessary to obtain ductile iron with good impact toughness at-50℃.In this study,without adding any additional alloying elements,by optimizing the chemical composition of the cast iron and subsequently annealing the castings,a nearly 100%ferrite matrix structure was obtained.The resulting ductile iron exhibits a tensile strength of≥380 MPa and a yield strength of≥230 MPa,which meets the mechanical property requirements of the national standard QT400-18L and the European standard EN-GJS-400-18LT cast irons.At the same time,it meets the average value of-50℃low temperature impact absorption energy≥12 J,and the single value is≥9 J,and its comprehensive mechanical properties have reached the expected target.