| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of cracking in a base material even if preheating is not executed, to impart excellent machinability after cladding by welding to a welding material and to stabilize its hardness after supercooling treatment, in a component deciding method by a Schaeffler diagram, by specifying the Ni equivalent and Cr equivalent and deciding them so as to lie in an austenitic region. SOLUTION: In a welding material for hardening cladding by welding in which a cast iron base material is clad by welding without preheating the base material and is thereafter hardened by supercooling, as for the componental compsn. of the material, the components are decided so as to satisfy the Ni equivalent and Cr equivalent contained in the region in a Schaeffler diagram by which the difference in the hardness before and after the supercooling in a state of being clad by welding is regulated to a prescribed value or above. In this method, Ni equivalent is decided to 34 to 37.5 and the Cr equivalent to 3.5 to 4, and, also, they are decided to lie in an austenitic region (above the boundary line La). Furthermore, at the time of adding Co by 0.5 to 1.5wt.%, the hardness difference Hv 200 can be secured even in the case the Ni equivalent is increased to about 38. |
