Hard Chrome Plating Training Course
Contributing Authors
Larry Zitko, ChromeTech
George Cushnie, NMFRC
Paul Chalmer
Randy Taylor, Advanced Tooling Corp.
Table of Contents
Section 2: Introduction To Hard Chrome Plating
- What is Hard Chrome Plating?
- Hard Chrome vs. Decorative Chrome
- Why We Use Hard Chrome
- Hardness
- Abrasion Resistance
- Low Coefficient of Friction
- Good Adhesion
- High Oil Retention
- High Melting Point
- Thermal Conductivity
- Lubricity
- Corrosion Resistance
- Section 2 Quiz
Section 3: Process Chemistry And Equipment
- Chromium—Chemical Terminology
- Types of Plating Baths in Common Use
- Conventional, Single-Catalyst Bath
- Fluoride, Mixed-Catalyst Bath
- High-speedn Non-etch, Proprietary Bath
- Electricity and Hard Chrome Plating
- Power Supplies Used for Hard Chrome Plating Systems
- Factors in Choosing a Power Supply for Hard Chrome Plating 9
- Air Cooling vs. Wate Cooling for Power Supplies
- Rectifier Bussing and Tank Bus Bars
- 3 Bus Bar Design
- 2 Bus Bar Design
- Tanks
- Chrome Plating Tanks
- Environmental Releases of Chromium from Plating Tanks
- Alkaline Electrostrip Tanks
- Scrub/Clean/Electroclean Tanks
- Rinse Tanks
- Anodes
- Solution Heating
- Solution Cooling
- Solution Agitation
- Exhaust Ventilation and Air Pollution Control
- Encapsulating Hood
- Exhaust Fans
- Environmental Releases of Chromium to Air
- Air Pollution Control
- Section 3 Quiz
- Preplate Analysis
- Stress Relief Bake
- Shot Peen
- Pre-cleaning
- Masking
- Racking/Fixturing
- Cleaning
- Water Break Test
- Activation/Etch
- Chrome Plating
- Amps vs.Volts
- Rinsing
- Hydrogen Embrittlement Relief
- Chromium Stripping
- Plating on Special Base Metal
- Section 4 Quiz
- Poor Chrome Appearance
- Poor or Partial Coverage
- Anode Placement and Size
- Poor Throwing Power
- Trees
- Poor Adhesion
- Roughness
- Pitting
- Arcing
- Poor Corrosion Resistance
- Micro-Cracking
- Macro (Mud) Cracking
- Slow Plating Rates
- Uneven Chromium Deposition
- Wild Chrome
- Section 5 Quiz
Section 6: Plating Bath Impurities And Treatment Technologies
- Analytical Data
- Preventing Contamination and Removing Contaminants
- Trivalent Chromium (Cr+3)
- Metallic Impurities - Tramp Metals
- Metallic Impurity Limits
- Dummy Plating
- Ion Transfer - Porous Pot
- Ion Transfer - Membrane Type
- Advanced Membrane Technologies
- Ion Exchange
- Chloride
- Suspended Solids
- Oil and Grease
- Section 6 Quiz
- Health Risks Associated with Exposure to Hexavalent Chromium
- Skin Contact
- Ingestion
- Breathing
- Additional Safety Measures
- Protect Yourself in Case of an Accident
- Section 7 Quiz
Section 8: Pollution Prevention
- What is Pollution Prevention (P2)?
- Benefits of P2
- P2 in Action
- Rinse Water P2 Techniques
- Rinsing
- What is Hazardous Waste?
- Prevent Bath Contamination
- Air Emissions
- P2 Implementation
- P2 Summary
- Section 8 Quiz
Appendix 1: Answers to Quizzes
Appendix 2: Acronyms and Abbreviations
Appendix 3: Reverse Etch Times
Appendix 4: Calculation of Surface Area
Appendix 5: Plating Parts Using a Plating Log
Appendix 6: Amps vs.Volts
Appendix 7: Troubleshooting Summary
Appendix 8: Conversion of Degrees Baumé to Concentrate for Chromic Acid
Appendix 9: Tracking Down Voltage Drops
Appendix 10: Conversion of Units
Appendix 11: Glossary