摘要
以废钢为主要原材料(20%生铁+20%回炉料+60%废钢),使用中频感应电炉熔炼,采用中间加入和镜面加入联合增碳方式,制备了合成球墨铸铁QT450-23铸件。合成铸铁球化级别1级,球化率95%,石墨圆整,球径10～20μm,基体为100%铁素体。合成铸铁抗拉强度为450MPa,伸长率为23.3%。在高温组织中,奥氏体枝晶发达,显著提高材料的冲击韧性,V型缺口冲击试样常温冲击韧性为18.4 J/cm2,是相同成分和工艺条件下,传统生铁为主配方球铁的2倍。
High strength and ductility synthetic ductile cast iron was prepared using scrap steel as the mainly raw material（20% pig iron＋20% scrap returns＋60% scrap steel）.The carbon content of the melt was modulated with recarburization process during melting and regulated just before finishing melting process by adding powder carbon on the melt surface.The microstructure with first class spheroidizing grade,95% spheroidization rate,round shaped graphite with 10 μm to 20 μm diameter and 100% ferrite matrix was checked in the high strength and ductility synthetic ductile cast iron.The produced synthetic ductile cast iron castings had tensile strength of 450 MPa,tensile elongation of 23.3% and impact toughness of 18.4 J/cm^2 with a standard V-notched impact specimen.It is found the large percentage of austenite dendrites is formed in synthetic ductile iron at high temperature.the impact toughness with a standard V-notched impact specimen of the prepared castings doubles the impact toughness value of other specimens prepared by traditional method using pig iron as mainly materials.
出处
《热加工工艺》
CSCD
北大核心
2010年第7期27-29,33,共4页
Hot Working Technology
关键词
合成球墨铸铁
球化率
奥氏体枝晶
力学性能
synthetic ductile iron
spheroidization rate
austenite dendrites
mechanical property
