초록 ▼

An iron-base article such as a camshaft has a remelted layer of high wear resistance on a cam surface, for example. To make such an iron-base article, molten metal is poured into a mold with a chill set therein to cast an iron-base article having a chilled region formed in contact with said chill. T

An iron-base article such as a camshaft has a remelted layer of high wear resistance on a cam surface, for example. To make such an iron-base article, molten metal is poured into a mold with a chill set therein to cast an iron-base article having a chilled region formed in contact with said chill. Then, metal powder which provides wear resistance upon being mixed is added to at least a portion of said chilled region. A high level of energy is applied to the portion of the chilled region to heat and remelt the same, and the remelted portion is thereafter cooled to form a remelted layer therein.

대표청구항 ▼

A method for remelting and hardening the cam surface of a camshaft the steps comprising: applying a high level of energy from a plasma arc generated by a plasma torch to the cam surface of the camshaft to be remelted and hardened continually at a predetermined obtuse angle to said cam surface to be

A method for remelting and hardening the cam surface of a camshaft the steps comprising: applying a high level of energy from a plasma arc generated by a plasma torch to the cam surface of the camshaft to be remelted and hardened continually at a predetermined obtuse angle to said cam surface to be remelted, the angle said high level of energy is applied to said cam surface varying as said camshaft is rotated so as to maintain said high level of energy continually at said predetermined obtuse angle to said cam surface as said cam shaft and said torch are rotated relative to each other; while applying said high level of plasma arc energy to said cam surface, rotating said plasma torch generating said plasma arc and said cam surface being remelted and hardened with respect to each other and, during said rotating, maintaining said plasma torch applying said energy continually at said predetermined obtuse angle to a line tangential to the cam surface undergoing remelting so that said surface undergoing remelting is slightly lower than the immediately preceding surface remelted while said preceding remelted surface hardens; and continuing said rotating, remelting and hardening until all of said cam surface to be hardened has been remelted and hardened.