Wang W.,Tianjin University of Technology |
Liu Q.-S.,Tianjin University of Technology |
Yan Z.-S.,Tianjin Pipe Manufacturing Corporation |
Zhang C.-Y.,Tianjin Pipe Manufacturing Corporation |
You C.,Tianjin University of Technology
Cailiao Kexue yu Gongyi/Material Science and Technology | Year: 2013
For the identification of mesothermal transformation characteristic in the ultra-high carbon steel, the microstructure and mechanical properties of the bainite formed during isothermal treatment at 150 °C and 200 °C in the Fe-1.44%C-1.52%Cr-0.32%Si-0.62%Mn ultra high carbon steel have been studied by using X-ray diffraction(XRD) analysis, optical microscope observation, hardness and impact toughness test. Experimental results show that both bainite transformation and cementite precipitation occur whatever isothermally treating at 150 °C or 200 °C, and the clavate feature of bainite is different from martensite which has acicular morphology. The length-width ratio of bainite rod formed at 200 °C is larger than that at 150 °C, and the feature of bainite gradually develop into bundles which is consistent of paralleled bainite rod with the increasing time, and the hardness level of bainite decrease thereupon. This means that the bainite which formed at different isothermal conditions in the experiment steel has different microstructure and mechanical property characteristics.