ảnh hưởng của mangan đến tính chất gang cầu phrrit trạng thái đúc

Tóm tắt

The production of ductile iron is influenced by a large number of metallurgical, heat transfer and designing parameters. The first step of the production of ductile iron castings is thecareful selection of the charge materials.tIThis paper presents the effect of the chemical composition on the structure and properties of ferrite ductile iron as-cast. This very brief survey shows that, in order to obtain ductile irongrade FCD 450, chemical composition of melt iron must be: Cdl > 4.3%; ratio C/Si = 1.4 - 1.8; residual magnesium is about 0.04 - 0.065%; S < 0.03% and there should be pig iron in thecharge.It is well known that manganese segregates to cell boundaries, especially in heavy sectioncastings requireing long solidification time and promotes the fonnation of pearlite in theseregions. The pearlite embritlles the Ductile Iron and in order to invoid its fonnation, 0,35% Mnis recommended as the maximum concentration