The Effest of Matrix of Nodular Graphite Cast Iron on Machinability in Lathe Turning - Cutting Force, Cutting Ratio and Shear Angle-

球狀黑鉛鑄鐵의 其他組織이 切削性에 미치는 영향 I

The orthogonal cutting method of the nodular graphite cast iron in the lathe turning, whose matrix were formulated under two kinds of annealing conditions, has been experimentally studied and the results investigated. The various characteristics of machinabilities of the nodular cast iron, depending upon its matrix, have been obtained from the results as follows. (1) As depth of cut increases, the cutting ratio and the shear angles tend to slightly increase, and as the containing quantity of ferrite matrix increases, they slightly decrease. (2) As depth of cut increases, the cutting force increases in an approximate straight line, and as the containing quantity of ferrite matrix increases, they decreases and the decreasing rate is about 20-30%. (3) As the containing quantity of ferrite matrix increases, the friction force acting on the tool face decreases and the decreasing rate is about 34-40% in case of the lower depth of cut, but in case of the higher depth of cut the decreasing rate is very small. (4) Both shearing force and vertical force show a lineal increases, and according as ferrite matrix increases there is a decrease by 25% in shearing force and a 12-25% decrease in vertical force. (5) Shearing speed and chip flow speed keep almost a constant value irrespective of matrix.

본 연구에서는 국내에서 생산되고 있는 구상흑연주철을 이단으로 어니일링하 여 기타조직을 3가지(p$_{1}$:28.88% 페라이트, 63.5% 퍼얼라이트, p$_{2}$:49.7% 페 라이트, 42.2% 퍼얼라이트, p$_{3}$:71.26% 페라이트, 22.3% 퍼얼라이트)로 변화시켜 족삭에서 이차원절삭실험을 실시하여 기타조직에 따라 제절삭성(절삭력, 절삭비, 전단 각 및 침의 흐름속도)을 비교검토 하므로서 어니일링효과가 절삭성에 미치는 영향을 검토 연구하였다.