球状黒鉛鋳鉄の静的及び疲労強度に及ぼす鋳肌表面粗さの影響

抄録

  Tensile test and fatigue tests under cyclic tensile load and cyclic rotating-bending load were conducted on several spheroidal graphite (SG) cast irons with casting skin, and the following results were obtained. The tensile strength, elongation and fatigue strength of SG cast iron with casting surfaces are considerably smaller than those of iron with machined surface, and decreases as skin roughness becomes larger. This tendency is due mainly to stress concentration generated from the roughness of the casting skin. Fatigue strength under cyclic rotating-bending load is affected to a greater extent by surface roughness than under cyclic tensile load.