微細パーライト球状黒鉛鋳鉄の機械的性質に及ぼす黒鉛粒数とパーライト層間隔の影響

摘要

In this study, the effects of various amounts of copper (Cu) addition on mechanical properties of spheroidal graphite cast irons containing 1.0 mass percent manganese (Mn) and rare earth elements (RE) were investigated. The effects of graphite nodule count and pearlite lamellar spacing on mechanical properties of spheroidal graphite cast irons containing 1.0 mass percent Mn and 2.5 mass percent Cu were also investigated. As a result, tensile strength increased with increasing Cu addition. Especially, high tensile strengths of 900 and more than 1200 MPa were obtained in Y-block and 10 mm diameter specimens added with 1.0 mass percent Mn and 2.5 mass percent Cu, respectively. On the other hand, in different graphite nodule count specimens added with 1.0 mass percent Mn and 2.5 mass percent Cu, tensile strength and hardness increased with decreasing thickness of the specimens. Fine pearlite lamellar spacing in thin section specimens was observed by means of field emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM).