| 摘要 |
PURPOSE:To obtain the excellent performance suitable for an intake valve, etc., by forming the alloying layer including a specific Mo by projecting a high density energy from the above of the Mo alloying material which is arranged on the valve face and performing a heat treatment at the specified temp. CONSTITUTION:An Mo or Mo containing alloy is arranged as an alloying material on the face 2 of the valve main body 1 or a martensite group heat resistant steel and the alloying material and the base metal surface layer of the lower side thereof are rapidly melted by projecting a high density energy beam from the above thereof. In succession with stopping the projection of the high density energy beam, the heat quickly moves to the base metal side and the melted alloying layer 3 thereof is frozen with its rapid cooling. In this case, the arrangement amount per unit area of the alloying material is made to become 1-15wt% on the Mo of the alloying layer finally obtd. Since the alloying layer thus obtd. becomes in the hardened state, an annealing is performed at the temp. within the range of 300-600 deg.C in succession, the wear resistance is increased and counter part attack is reduced as well. |
