BRIGHT FINISH-ANNEALING METHOD OF IRON-CHROMIUM- ALUMINUM ALLOY SHEET, BRIGHT FINISH-ANNEALING EQUIPMENT AND METHOD FOR EVALUATING OXIDATION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To obtain the uniform and good color tone and oxidation resistance on the surface of an Fe-Cr-Al alloy sheet as a product by constituting atmospheric gas in a finish-annealing furnace of thin Fe-Cr-Al alloy sheet of H2 and N2 and controlling the H2 concn. in the atmospheric gas based on the whiteness on the material surface after finish-annealing. ;SOLUTION: Cold-rollings and annealings are repeated several times, and a coiled material rolled with finish-rolling is recoiled, and after annealing this material 4 in the bright finish-annealing furnace 1, this material is again coiled to obtain the product coil of the Fe-Cr-Al alloy sheet. The atmospheric gas composed of the H2 gas and the N2 gas is supplied into the finish-annealing furnace 1 with an atmospheric gas supplying device 5. When the whiteness based on the signal from a whiteness meter 9 becomes lower than a prescribed value, an atmospheric gas concn. adjusting device 8 decides so that the H2 concn. becomes high in the reverse proportion with the detected value of the whiteness, and signals for controlling opening degrees of the flow rate adjusting valves 6, 7 for H2 gas and N2 gas, are changed so that the H2 concn. becomes the decided value.;COPYRIGHT: (C)2000,JPO