“…The elements that are often alloyed into gray cast iron to improve their properties are manganese [8], sulfur [9], niobium [10][11][12], copper [13], molybdenum [14], silicon [15], and chromium [16]. Improved properties are also carried out by modifying the phase through processes such as quenching-tempering [17], austempering [18], spheroidizing [19], laser surface treatment [20], and flame hardening [21]. Changing the shape of sharp flake graphite into spherical graphite will reduce the stress concentration so that the cast iron becomes stronger and harder.…”