| 摘要 |
PURPOSE:To obtain the high wear-resistant roll for a heat treatment having excellent thermal impact resistance and build-up resistance by providing a cermet coating of a specific compsn. consisting of boride systems CrB, MoB, WB, TiB2, ZrB2, etc., and metals. CONSTITUTION:This hearth roll has the cermet coating contg. 20-80vol.% at least one kind among the boride systems CrB, MoB, WB, TiB2, and ZrB2 and consisting of the balance substantially metal. The roll exhibits the excellent high-temp. wear resistance and thermal impact resistance and has the build-up preventive property when the roll is used in an oxidizing or reducing atmosphere. The life of the roll is thus prolonged. The above-mentioned cermet covering is formed by coating a mixture composed of the boride having a prescribed compsn. and the metal onto the roll base body made of a heat resisting cast steel by a vacuum plasma thermal spraying method, etc. Heat resisting alloys of a CoCrAlY system, NiCrAlY system, etc., or Ni-Cr alloy, etc., are usable for the above-mentioned metal component. |
