Solidification structures and frictional wear characteristics of high P cast iron containing 3.3 mass%C, 1.7 mass%Si, 1.4 mass%Mn, 0.3-3.0 mass%P, 0.37 mass%Cr, 0.20 mass%V were examined with an image analyzer and original braking test machine. High P cast iron consists of steadite, eutectic cementite and flaky graphite distributed in pearlitic matrix. The addition of higher levels of P increases the steadite, which raises frictional wear resistance against the wheel steel.The wear resistance effectively improved with the addition of about 0.6 mass%P. The braking ability also improved with the addition of more than 1 mass%P at the initial braking speed of above 15 m/s. The contact surface was heated above 990 K at the initial braking speed of 25 m/s and the steadite partially melted or softened, which enhanced the braking ability of cast iron.
