Method of determining components of a welding material having been overlaid onto a cast iron base metal

摘要

A welding material for hard-facing which is to be hardened by a supercooling treatment after overlaying onto a cast iron base metal has a basic component composition which meets, in an overlaid condition, both a first condition and a second condition. The first condition is that a nickel (Ni) equivalent and a chromium (Cr) equivalent fall within that region to be defined in Schaeffler's structure diagram in which a difference in hardness before and after the supercooling treatment is a predetermined value or above. The second condition is that a starting temperature of martensitic transformation is a predetermined temperature or below. The components of the welding material are determined by defining in Schaeffler's structure diagram a region in which a difference in hardness before and after the supercooling treatment becomes a predetermined value or above, obtaining a target composition in which the Ni equivalent and the Cr equivalent fall within the region and in which the starting temperature of martensitic transformation is a predetermined temperature or below, and determining the composition of basic components such that the target composition is attained in an overlaid condition.