Abstract: This invention aims at providing a method of continuously carburizing a metal strip, which is capable of providing industrially optimum carburization conditions while attaining non-soot-generating atmospheric data, desired carburization concentration distribution and desired carburization rate, in a case where a strip passed through a carburization furnace is carburized continuously in a surface reaction rate-governing area in which the carbon concentration in a superficial layer of the strip has not yet reached an equilibruim level with respect to the time.

Abstract: A heating apparatus includes at least a pair of regenerative burner units having a fuel injection nozzle and a heat regenerator provided for a combustion air supply path. One regenerative burner unit is supplied with fuel through a fuel shut-off valve and a fuel change-over valve, and supplied with combustion air through a supply and exhaust change-over valve to perform combustion operation. The other regenerative burner unit performs heat regenerating operation by passing a combustion waste gas. Operations of the fuel shut-off valve, the fuel change-over valve and the supply and exhaust change-over valve are controlled depending upon an operation parameter of the heating apparatus.