TEMPERED MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AUSTEMPERED LOW ALLOYED BAINITIC DUCTILE IRON

Austempered bainitic ductile iron has been widely used in machinery components and parts due to its low fabrication cost, excellent mechanical properties, and abrasive wear resistance. In order to get a fine bainitic matrix, austempering process is usually adopted which consists of austenitizing temperature, austempering temperature and time. For quenched ductile cast iron, tempering plays an important role in subsequent heat treatment process. However, less attention has been paid on the microstructural evolution and mechanical properties of the austempered bainitic ductile iron after tempering treatment. Thus, in this work, 3.55C-1.95Si-0.36Mn-3.58Ni-0.708Cu0.92Mo-0.65Cr (mass fraction, %) bainitic ductile iron was subjected to austempering and subsequent tempering treatment, and the effect of tempering on microstructures and properties has been investigated by using OM, EP*国家高技术研究发展计划资助项目2012AA03A508 收到初稿日期: 2015-12-03,收到修改稿日期: 2016-04-01 作者简介:崔君军,女, 1987年生,博士生 DOI: 10.11900/0412.1961.2015.00625 第778-786页 pp.778-786