Far-infrared radiation multi-stage type heating furnace for steel sheets for hot stamping

摘要

A far-infrared radiation multi-stage type heating furnace for steel sheets for hot stamping, the furnace including far-infrared radiation heaters having flexibility that are prevented from deflecting even during heating at temperatures ranging from the Ac₃ transformation temperature to 950° C. The furnace includes: multiple-staged heating units that accommodate steel sheets, each heating unit formed by thermal insulation materials disposed around the periphery; and far-infrared radiation heaters positioned above and below the heating units. A far-infrared radiation heater is received by first metal strips. The first metal strips are disposed so that their strong axis direction approximately corresponds to the direction of gravity and supported by support pieces so as to be expandable and contractible in a longitudinal direction by thermal expansion or thermal contraction. The support pieces are disposed outside the thermal insulation materials in the heating units and a ceiling unit.