Microstructure and mechanical properties of austempered high boron cast iron
A new type of austempered high boron cast iron has been developed. The microstructure and mechanical properties have been studied for different austempering combinations. The experiment indicated that the austempered high boron cast iron comprises a dendritic matrix and interdendritic eutectic borides in as-cast condition. The matrix is made up of pearlite and ferrite, and the eutectic boride with a chemical formula of M2B (M represents Fe, Cr, Mn or Mo), which is much like that of carbide in high chromium white cast iron. Pure ausferrite structure of austempered high boron white cast iron that consisted of bainitic ferrite and carbon-riched retained austenite can be obtained by austempering treatment. No carbide precipitates in the bainitic ferrite structure and the morphology of boride remains almost unchanged. The boride particles precipitate during the course of austenitizing. The hardness of the austempered high boron white cast iron decreases with increasing of the austempering temperature, from 250°C to 400°C. The impact toughness is about 3-5 J/cm2 at room temperature and its impact fracture fractogragh indicates that the fracture is caused by brittle fracture of boride. The austempered high boron white cast iron is a new kind of wear resistant material with bright application prospect.
high boron cast iron austempering treatment ausferrite structure boride
Zheng Shuai Chen Xiang Li Yanxiang
Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China Key Laboratory for
国际会议
The 11th Asian Foundry Congress(第11届亚洲铸造会议 AFC-11)
广州
英文
1-7
2011-11-12（万方平台首次上网日期，不代表论文的发表时间）