Fracture toughness and tribological wear behaviour of micro alloyed pearlitic-ferritic ductile cast iron

Fracture toughness and wear behaviour of micro alloyed ductile iron were investigated. Hardness, fracture, fracture toughness and wear tests were carried out on the ductile irons samples (D₁, D₂, D₃, D₄ and D₅), containing micro alloyed nickel, molybdenum, copper and chromium in an amount of 0.2 % or less. They were characterized using optical metallurgical microscope and they contained pearlitic-ferritic matrix structure. They were subjected to wear test at room temperature based on pin-on-disk operation. Fracture surfaces and the wear track were studied using scanning electron microscope and found that the fracture surfaces majorly consist of fibrous with little cleavage fracture pattern in some samples. Wear mechanism is delamination with adhesive wear behavior. The specific wear rate was found to decrease with increasing hardness of the material and coefficient of friction of the ductile irons during test.