• CN: 11-2187/TH
  • ISSN: 0577-6686

›› 1982, Vol. 18 ›› Issue (2): 58-65.

• Article • Previous Articles     Next Articles

MICROSCOPIC STRUCTURE OF VERMICULAR GRAPHITF CAST IRON

Li Chuenli;Wu Dehai;Ho Zuozhi;Hu Wenyi   

  1. Tsinghua university Zhengzhou Research Institute of Mechanical
  • Published:1982-03-01

Abstract: It has been observed that specimens was treated with deep-etching and thermal-oxidation etching processes to make use of scanning electron microscope. So that the three demensional stereo morphology and orientation of crystal of vermicular graphite may be revealed. The number and structure of the eutectic cells in ver micular graphite cast iron were observed also with both optical microscope and scanning electron microscope.It was demonstrated that vermicular graphite may be obtained in cast iron treated with modifying agent in which the rare earth elements were involved; the growth at the end of it was similar to the spheroidal graphites It was also similar to flake graphite because it was connected each other in same eutectic cell. With the thermal oxidation process it was revealed that the (0001) plane was arranged along to thecircumference at the end of vermicular graphite. So that there are annual ring structure at it. The (0001) plane at the branches was a anged along to the longitudinal: and the orientation of it changed freguently So that the vermicular graphite was polycrystalline. As mentioned abore the model of the crystal plane orientation of vermicular graphite was drown by authors.Both the size and the number of the eutectic cell in vermicular graphite iron was intermediate between the flake and spheroidal. And the structure of it has common characteristic both of flake and of spheroidal also. As stated above the corresponding model was drown by authors.It may be concluded that the properties of vermicular graphite cast iron was entirely consistant with the characteristic on the microscopic structure of it.