Pitting Analysis of the Local Exhaust Valve Seat of Engine

Analysis of the exhaust valve seat with local pitting was conducted by means of macrostructure and microstructure examination,chemical composition analysis and hardness test. The results indicate that the rocker was not well contact with the valve top of the exhaust valve. It caused the valve could not rotate,which resulted in the eccentric wear of the stem and local leakage of the seat of the exhaust valve. Finally the exhaust valve seat appeared pitting at local position.