| 摘要 |
Gray cast iron, which is used in the manufacture of piston rings and sleeves for internal combustion engines, and which comprises: a bainitic, martensitic, pearlitic or ferritic metallic matrix, with an amount of equivalent carbide from 4 to 5 % and including from 2 to 5 % of steadite and from 1 to 10 % of cementite, which has been modified by the presence from 0.02 to 2 % by weight of boron and from about 0.5 to 5 % by volumne of particles of at least a high hardness MC type carbide, said particles being dispersed in the cast metallic matrix, M being at least one of the elements selected from the group consisting of Ti, Ta, Zr, Hf, Cr, V and Nb, said metallic matrix presenting a first basic surface and a second wear surface, which is spaced from said first surface and which is defined by the projection of the hard particles existing in said matrix. |
