| 摘要 |
A plurality of layers in which the carbon content is higher than that of a treated material made of steel, but 1.0 wt% or less, is laminated to at least a portion of the treated material, the outermost surface layer among the plurality of layers having the highest carbon concentration. The method includes at least: a step of spraying a powder containing carbon onto at least a portion of a treated material made of steel, forming a first layer of higher carbon concentration than the treated material; and a step of spraying a powder containing carbon onto at least a portion of the first layer, forming a second layer of higher carbon concentration than the first layer, the carbon concentration of the plurality of layers, including the first layer and the second layer, being 1.0 wt% or less. |
