气氛控制教育训练_PowerMax Atmosphere Training.ppt

熱處理基本原理 熱處理的分類 (1) 真空熱處理 (2) 氣氛熱處理 A. 馬氏體淬火 B. 貝氏體淬火 #1 鋼的貝氏體淬火 #2 鐵的貝氏體淬火 馬氏體淬火 Martensite Hardening Austempering UBQA ISOMETRIC The Austemper Heat Treat Process for Cast Iron 滲碳原理 滲碳的三要素 1. 溫度 2. 碳勢(Carbon Potential) 3. 時間 SSI MMI Atmospheres Endothermic Atmosphere Cracked Natural Gas Cracked Propane Nitrogen / Methanol Atmosphere Methanol CH3OH Trouble Shooting C% Carbon Potential ZIRCONIA O2 RESPONSE Ec = 0.0276TR log (Pf /Pa) millivolts Endothermic Gas Endothermic GasAtmosphere Reaction Review Methane/Air Gas Reaction 2CH4 + O2 + 4N2 + HEAT(1900°F) ? 4N2 + 4H2 + 2CO Typical Mixture Ratio (Air Flow / Gas Flow): 2.50 - 3.00 Output Flow Calculation: (Air Flow + Gas Flow) x 1.43 = Endo. Flow Endothermic GasAtmosphere Analysis Normal Gas Constituents Air/Methane Air/Propane Hydrogen Gas (H2) 40% 31% Nitrogen Gas (N2) 40% 46% Carbon Monoxide Gas (CO) 19.5 - 19.8% 22.5 - 22.8% Carbon Dioxide (CO2) 0.2 - 0.5% 0.2 - 0.5% Water Vapor (H2O) 0.1% 0.1% Unreacted Methane (CH4) 0.1% 0.1% Carbon Reversal Must cool cracked gas to less than 600F Keeps CO from becoming C+ CO2 Between 900 and 1300 Soot is formed You will see it everywhere Piping, flow meters, sample ports and furnace Endothermic GasMixing Equipment Endothermic GasMixing Equipment Endothermic GasMixing Equipment Endothermic GasFuel-Injection Mixing Endothermic GasFuel-Injection Interface Significant Components of a Carburizing Atmosphere CO Carbon Monoxide CO2 Carbon Dioxide N2 Nitrogen H2O Water H2 Hydrogen CH4 Natural Gas (Methane) Nitrogen / Methanol Methanol, Methyl alcohol, MeOH Formula = CH3OH Molecular weight = 32.04 Boiling point = 149 °F (65 °C) 1 liter of MeOH - yields approx. 64 SCFH of dissociated gas (1.7M3) Nitrogen / Methanol Nitrogen / Methanol Other Reactions 2CH3OH CO2 + C + 4H2 CH3OH