STEEL VALVE FOR INTERNAL-COMBUSTION ENGINE

摘要

PURPOSE:To improve the abrasion resistance of the contact surface with a locker arm of an intake/exhaust valve for an engine by forming an alloy layer made of steel as the material constituting the main part of the valve in alloy form with the metal element having a high melting point. CONSTITUTION:In an exhaust valve 1 for engine which is made of steel, an alloy layer 9 is formed onto the contact part with a locker arm at the upper edge part. Said alloy layer 9 is made of the steel in alloy form with the metal element having a high melting point, said steel constituting the main part of the valve. Said alloy layer is obtained by adding the aqueous solution of polyvinyl alcohol in 5% as bonding agent into tungsten powder having an average particle size of 40mu and arranging said tungsten powder into a layer form having a thickness of about 1mm except the peripheral edge part having a width of about 1.0mm at the edge part of the valve and then heating-drying said layer at 110 deg.C in the atmosphere for 20min and then melting said layer in the sealed state by argon gas by a laser gun.