METHOD FOR FORMING METAL FILM ON COLUMNAR BASE MATERIAL

PROBLEM TO BE SOLVED: To provide a method for forming a metal film, capable of dissolving deviation in film thickness or denseness of composition after remelting by dissolving partial concentration and shortage of remelting heat to suppress the occurrence of an excessive applying portion or low applying portion of melting energy when remelting a columnar base material having a corner portion in a tip corner.SOLUTION: A method for forming a metal film on a columnar base material comprises: a thermal spray step of fixing a thermally sprayed film on the entire end part of a columnar base material (1) including a tip surface (11) and a corner portion (1C) by thermally spraying a metal powder; and a remelting step of modifying the thermally sprayed film by remelting the thermally sprayed film by a heating piece (C) surrounding the side periphery of the columnar base material (1) to form a metal film on the surface of base material including the corner portion. In the remelting step, the columnar base material (1) is held in either of the drooped state of turning the tip surface (11) including the corner portion vertically downward or the inclined state of turning the tip surface (11) in an inclined direction at a predetermined inclination horizontally downward and is remelted while rotating the columnar base material (1) around a column axis (1A).SELECTED DRAWING: Figure 5 【課題】先端隅に角部を有する柱状母材に再溶融処理を行う場合において、再溶融熱の部分的な集中や不足を解消し、溶融エネルギーの過多付与部分や過少付与部分の発生を抑制することで、再溶融後の皮膜厚さや組成の緻密度の偏りを解消し得る金属皮膜の形成方法を提供する。【解決手段】先端面（１１）及び角部（１Ｃ）を含む柱状母材（１）の端部全体に、金属粉末の溶射によって溶射被膜を定着させる溶射工程と、柱状母材（１）の側周部を囲う加熱子（Ｃ）によって前記溶射皮膜を再溶融することにより、溶射皮膜を変性させて、前記角部を含む母材表面に金属皮膜を形成する再溶融工程と、を具備する。再溶融工程において、柱状母材（１）を、前記角部を含む先端面（１１）が鉛直下方を向いた垂下状態、又は所定の対水平下方傾斜角で斜め方向を向いた傾斜状態のいずれかの状態に保持し、かつ、柱状母材（１）を柱軸（１Ａ）周りに回転させながら再溶融する。【選択図】 図５