DEW POINT CONTROL METHOD FOR REDUCTION ATMOSPHERIC FURNACE, REDUCTION ATMOSPHERIC FURNACE, METHOD FOR PRODUCING COLD ROLLED STEEL SHEET, AND METHOD FOR PRODUCING HOT DIP GALVANIZED STEEL SHEET

• Main Author: KASAHARA KYOSUKE
• Format: Patent
• Language: English; Japanese
• Published: 26.11.2020
• Subjects: ALLOYS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a dew point control method capable of increasing and controlling the dew point in a reduction atmospheric furnace at high precision by economically excellent means.SOLUTION: In a reduction atmospheric furnace using a nitrogen gas and a hydrogen gas as reduction gases to be fed, the reduction gases are mixed with an oxygen-containing gas, and the oxygen concentration in the reduction gases to be fed is controlled, thus the dew point in the furnace is regulated to -20 to 0°C.SELECTED DRAWING: Figure 2 【課題】経済性に優れた手法で還元性雰囲気炉内の露点を高精度に上昇させ、制御することができる露点制御方法を提供することを目的とする。【解決手段】供給する還元性ガスとして、窒素ガスと水素ガスを用いる還元性雰囲気炉において、還元性ガスに、酸素を含有する気体を混合させ、供給する還元性ガス中の酸素濃度を制御することで、炉内の露点を−２０℃〜０℃に調整する【選択図】図２