Atmosphere Recovery, Inc. High Performance, Low Emission Carburizing Furnace Atmosphere Generation & Control Using Rapid Laser-Based Gas Analysis October 11, 2000 Ronald R. Rich Atmosphere Recovery, Inc. and Ralph W. Larson Dana Corporation

Topics Presented Carburizing Atmosphere Technology & Issues Atmosphere Gas Monitoring Needs & Methods ARI Laser Gas Analyzer (LGA)/Controller System Improved Process Development History New Approaches to Gas Carburizing with LGA Metallurgical Findings & Technology Status

Carburizing Use & Purpose Typical Parts (Gears) Typical Furnace (Batch) Improves Steel Wear Resistance on Part Surfaces (Adds Carbon) Maintains Steel “Toughness” at Part Depth (Lower Carbon) Parts to Heated to High Temperatures in a Gas “Atmosphere” Atmosphere Provides Reactive Chemistry Containing Carbon in Gas Form in a Reducing Environment

Traditional Carburizing Atmosphere Composition: CO~20%, N2~39%, H2~39%, 1% CH4, Balance: CO2, H2O, O2 Air Exhaust Stack Endogas At Metal Surface: 2H2+2CO+3Fe  Fe3C+2H2O+CO2 3Fe + CH4  Fe3C + 2H2 Natural Gas

Typical Carburizing Operation

Major Concerns Related to Atmosphere Carburizing Process Control Problems with Existing Technologies Variable Production Part Parameters (Case Depth, %Carbon) Many Atmosphere Constituents Inferred Inefficient Control Algorithms to Employed to Reduce Sooting Limited Warning of Equipment Maintenance Process Improvement Potential (Over 60 Years Old) Improved Part Quality & Performance Reduced Atmosphere Consumption Furnace Cycle Time Reductions Higher Performing Surface Treatment Options High Levels of Carbon Monoxide Air Emissions Inefficient Use of Atmosphere Gas and Energy

Most Industrial Furnace Atmosphere Gases Similar Carburizing, Carbonitriding, & Nitriding N2, CO, H2, CO2, H2O, CH4, O2, NH3, CH3OH Atmosphere Tempering and Annealing N2, H2, CO, CO2, H2O, CH4, O2, NH3, Ar Copper and Aluminum Brazing Powdered Metal Sintering N2, CO, H2, CO2, H2O, CxHy, O2

Typical Atmosphere Control Measures Only One Gas Species Types Zirconia Oxygen Probe – Measures Oxygen Dew Point Meters – Measures Water Vapor Electrochemical Cells – Low Range Single Gases Benefits Lower Capital Cost Limited Calibration Requirements Disadvantages All Other Gas Constituents Not Measured or Controlled Many Assumptions About Other Gas Constituents Needed Requires High Atmosphere Flows for Adequate Control Inaccurate Correction for Most Atmosphere Variances Limited Process Control Variation & Improvement Options

Carburizing Atmosphere Monitoring Improved With Infrared Analyzers Usually Measures Only Three More Gases Carbon Monoxide Carbon Dioxide Methane Does Not Measure Other Significant Gases Oxygen (Additional Sensor Required) Water Vapor (Theoretically Could) Hydrogen Nitrogen and Inert Gases Non-Linear Response Accurate Only Within Limited Concentration Range High/Low Constituent Concentration Interference Reference Cell Requires Frequent Calibration

Benefits of Complete Atmosphere Gas Analysis Improved Carbon & Nitriding Potential Control Improved Oxidation/Reduction Potential Control Reduction in Atmosphere Consumption Allows Use of “Non-Standard” Atmosphere Gases Control of “Cleaner” Furnace Atmospheres Hydrogen/Nitrogen/Inert Combinations Carbon Dioxide/Hydrocarbon Mixtures Novel Mixtures for Improved Performance Sooting Reduced or Eliminated Early Warning of Some Furnace Maintenance Issues Potential for Reduced Furnace Cycle Times

Additional Benefits if Complete Atmosphere Analysis is Rapid (15 Seconds or Less) “Real Time” Process Monitoring, Control and R&D Correlation with Existing Furnace Sensors “Non-Equilibrium” Atmosphere Operation Accurate Carburizing Rate Assessment Greater Potential for Reduced Furnace Cycle Times Drastic Reduction in Atmosphere Consumption Efficient Use of “Non-Standard” Atmosphere Gases Early Warning of Many Furnace Maintenance Issues Improved Furnace Performance and Safety Monitoring

Conventional Complete Gas Analysis Technologies Gas Chromatography (GC) Moderate Price ($15,000 - $60,000) Slow (2 Minutes+) Frequent Calibration and Service Carrier Gas Needed Mass Spectroscopy (MS) Higher Price ($50,000 - $120,000) Fast if Vacuum Already Present (Can be Slow if Not) Expensive to Maintain Equal Mass Gases Require Additional Analysis (GC)

Raman Gas Analysis Principals Unique Frequency “Shift” for Each Type of Chemical Bond Measures Gases of All Types (Except Single Atoms) Rapid “Real Time” Response Rates Possible Signal Directly Proportional to Number of Gas Atoms 0-100% Gas Concentrations Measured with One Detector Resolution and Accuracy Depends On: Laser Power and Optics Variation (Including Cleanliness) Gas Concentration and Pressure Molecular Bond Type Background and Scattered Radiation Optical and Electronic Detector Circuitry

Some Atmosphere Raman Shift Spectra Source: NASA

Laser Raman Analysis Technologies External Cavity Raman Lasers (Under Development) Remote Fiber Optic Sensor Heads Higher Price Because of High Laser Power ($75,000 - $300,000) Fast Only if Laser Power High Expensive to Operate (Power, Cooling, Probe Tip?) Laser Beam Dangerous Less Accurate Internal Cavity Raman Laser (ARI’s “LGA” Design) Gas Sample Flows Through Instrument Moderate Price ($25,000 - $60,000) Fast if Detectors Selective Low Cost Operation Safe Low Power Laser Beam

Multiple Port ARI LGA System Furnace Gas 1 In Filter Assembly Valve Filter Furnace Gas 3 In Furnace Gas 2 In Filter Filter Generator Gas In Individual Gas Detectors Individual Gas Detectors Gas Sample Tube Laser Beam Plasma Cell Mirror Prism & Mirror Polarizer Sample Pump & Pressure Control Gas Outlet

ARI LGA Detector Features Gas Analysis Capabilities 8 Gas Species Detected Simultaneously Fast Detector Response (50 milliseconds) 50 Parts per Million to 100% Concentration Range More Accurate than NIST Calibration Gas Mixtures No Zero and Span Gas Requirement (Optional) Design Allows Customized Selection of Gas Species Lifetime and Servicing Two to Five Year Component Lifetimes Ten Minute Detector Exchange Individual Components Can Be Serviced and Cleaned

Additional LGA System Features Integrated Sample Flow Control & Monitoring Specialized Long Life Sample Filters (One Year +) Internal Sample Pump and Calibration Valves Low Volume Sample Gas Flows (200 ml/minute) Electronic Flow and Pressure Monitoring Optics and Enclosure Inerting (Standard for Atmosphere Analysis) Multiple Sample Ports (16 + Optional) Sample Line Purge and Back-flush (Optional) High Dew Point Atmosphere Operation (Optional) Integrated Electronics & Software “Open Hardware” Pentium/Pentium III PC “Open Software” Windows NT 4.0/Win2000 Based Many Local and Remote Displays and Data Storage Options Available Analog and Digital I/O Options Multiple Configurable Process and PLC Interface Options

Interior View of Subsystems Display, Keyboard, Serial & Network Ports Laser & Gas Sensor Assembly Optional I/O Card Slots Gas Flow Control Assembly Pentium PC Based Monitor/Controller Gas Sample Pump Win NT or DOS OS & 4.3 GB Hard Disk Multi-Port Control Options

Exterior View NEMA 4/12 Unit (131oF Maximum) Model 4EN Furnace Atmosphere Analyzer Cooling Unit Electrical & Communication Sample, Calibration & Inerting Gas Inputs

Interior View NEMA 12 Unit LGA Unit Sub-Assembly Integrated Multi-port Valves Integrated Sample Filters Power & Network Connections Calibration & Purge Gas Regulators

Sample Software Control Screens Main Control Screen Atmosphere Analysis Values

LGA Carburizing Applications External Atmosphere Generator Monitoring & Control Complete Furnace Atmosphere Control Including: Communications with PLC-Based Furnace Controller Real-Time Carbon Potential Correction of Oxygen Sensor Reduced Atmosphere Gas Usage & In-Situ Generation Stand-Alone PC Based Control System Integrating: Complete Furnace Atmosphere Control Improved Safety Monitoring Burner & Over Temperature Modules Oxygen Probes & Quench Tank Monitoring Part Load and Tray Tracking Interface with Plant SCADA and SPC Systems

Use for Rapid Generator Monitoring Expanded View Showing Rapid Variations

New Approaches to Carburizing Demonstrated at Dana Corp. Spicer Off-Highway Components Plymouth, MN

Plant Products and Processes Primarily Large Off-Road Axles and Gearsets Some Interdivisional Component Carburizing Atmosphere Heat Treat Processes Five “Carburizing” Furnaces Three “Endothermic” Generators

Improvements Initiated Because of New Air Emission Concerns Previously Recognized Air Emissions Smoke from Quenching Burner Combustion Gases Unrecognized Air Emissions Issues Carbon Monoxide (CO) from Atmosphere Use Comes from Atmosphere Generation, Leakage and Flaring - 10,000 to 200,000 ppm Original “Potential to Emit” Estimate - 231 Tons Per Year (TPY)

Rapid Gas Analysis Process Development 1993-1994 Environmental & Air Quality Monitoring Furnace Gas and Emission Testing Options for Industrial Furnace Process Modification Identified 1994 - Atmosphere Recovery, Inc. Founded Carburizing Heat Treat Furnace Atmosphere Recovery Research Dana & USDOE Sponsored Research Program Intent to Produce Systems 1995-1999 - Constructed and Tested Prototype Systems Numerous Papers and Presentations Plant and Process Energy and Environmental Awards 1999-2000 – Laser Gas Analyzer Product Demonstrations Endothermic and Exothermic Applications Tests with “Non-Standard” Atmospheres

Batch Furnace Modifications Side Pipe Waste Gas Exit with Cap Backup Safety Pressure Control Box and Dials Electronic Endothermic Gas Control Communication with Existing Controls Finding - Minimal Modifications Needed

2,000 lbs. Driveshaft “Crosses” Typical Test Load 2,000 lbs. Driveshaft “Crosses” Side View Top View

Initial Demonstration - Atmosphere Recovery Process IR-GC Later LGA Part of System

IR-GC (Later Replaced by LGA) Prototype System IR-GC (Later Replaced by LGA) Prototype Development, Assembly and Testing First Full Scale Operation - Aug. 6, 1997 Finding - Process Worked and Increased Furnace Productivity

Inter-Cavity Raman & GC Comparison on ARI Trial

System Location in Plant “Explosion Resistant” Test Area

Later Demonstrations - Integral Atmosphere Generation LGA is Integral Part of System

Example Results for Rapid Carburizing

Parts Testing – Typical Load Two Test Pins One by Plant One by Heavy Axle Division (HAD) 3 or 6 “Standard Heat Code” 8620 Planet Gears Per Load Tested by Plant Standard Load Locations Three As Tempered Sometimes Three as Quenched Three 8620/25/30 Test Pinions (Production Parts) All As Tempered One Tested by Plant Two Tested by HAD Two Carbon Profiles (Bar by HAD, Rod by Plant)

Case Depth and Profile of Parts RC50 Value Case Depth Always Obtained Faster Improvement Percentages Depends Primarily on Desired Final Case Depth (Shallower is Faster) Less Case Depth Variation in Load Hardness and Carbon Profile Consistent Profiles Consistent with Higher Surface Carbon Potentials Surface Hardness Also Acceptable Surface Cleanliness not Significant (8620/8625/8630)

Retained Austenite/Carbides in Parts Baseline ARI Accelerated “ARI Process Better (Lower Levels)” Levels Can Be Adjusted to Suit Desired Result Controllable Even with Wide Atmosphere Fluctuations

Grain Boundary Oxidation in Parts Baseline ARI Accelerated “ARI Process Better (Lower Levels)” Levels Can Be Adjusted to Suit Desired Result Controllable Even with Wide Atmosphere Fluctuations

Metallurgical Findings Summary Batch Cycle Times Faster (Load to Unload) Same Process Temperature (Typically 1750 Deg. F.) Case Depth of .040” – 35% to 50% Faster Case Depth of .065 – 20-30% Faster Less Case Depth Variation Though the Load Controllable Carbon Content/Hardness Profile Controllable Retained Austenite Levels Controllable Iron Carbide Levels Wide Variation in Atmosphere Constituents Tolerated Advanced Soot Control Algorithms Do Not Affect Parts All Parts Released for Production

ARI Technology Status Laser Gas Analyzer/Controller Systems Sales & Service Carburizing (Current Sales) Annealing (Current Sales) Nitriding (Future Sales) Brazing (Future Sales) Powdered Metal Sintering (Future Sales) Casting/Drawing (Future Sales) Integral Atmosphere Production Units Ready for Order Improved Atmosphere Recovery Prototype Ready for Trial Corporate Demonstration Sites Wanted