| 摘要 |
PURPOSE:To improve seizure resistance under boundary lubrication, by forming many voids in specific proportion in the vicinity of a sliding surface further specifying hardness of an iron ground so as to supply lubricating oil from the voids to a frictional surface under a condition of the boundary lubrication. CONSTITUTION:Voids are formed in 7-20% proportion in the vicinity of a sliding surface, further an iron ground in a part excepting the voids is specified in average to hardness of Hv 650 or more and 400 or less, and the soft iron ground part uses an iron system sintered material of 50% or less of a void area. The above material is composed generally containing by weight 0.1-2.0% carbon and 0.5-15% at least one or more of the elements Ni, Mo, Cr, Mn. As the method of preparing said material, mixed powder is compressed from its predetermined proportion of the void selecting a pressure in the range of 4-8ton/cm<2> and sintered for 30min-2hr at 1,100-1,300 deg.C, and as the process after sintering, cementation and cementation quenching or quenching treatments are performed under a uniformly heated condition. |
