Physics of Welding Continued. Physics of Welding Continued. Learning Activities Look up Keywords View Slides; Read Notes, Listen to lecture View Hi-speed Videos Do on-line workbook Do Excel Tutorial. Lesson Objectives When you finish this lesson you will understand:
Physics of Welding Continued • Learning Activities • Look up Keywords • View Slides; • Read Notes, • Listen to lecture • View Hi-speed Videos • Do on-line workbook • Do Excel Tutorial • Lesson Objectives • When you finish this lesson you will understand: • Wire melting modes • Power Supply Characteristics • Interactions between the arc and the power supplies • Principles of Magnetic Arc Blow Keywords Metal Transfer, Short Circuit Transfer, Pulsed Arc, Power Supply Characteristics, Open Circuit Voltage, Closed Circuit Current, Constant Voltage Power Supply, Constant Current Power Supply, Drooping Characteristic, Self Regulating Arc,Magnetic Arc Blow
Physics of Welding • Heat Input Concepts • Energy Sources • Arc Characteristics • Wire Melting
Gas Metal Arc Welding GMAW Modes of Metal Transfer Globular Spray Short Circuiting Pulsed Spray
Pulsed Arc Tandom Arc
Video View the Arc Welding High Speed Videos from the Video Web Page on the WE300 Website
Questions? • Turn to the person sitting next to you and discuss (1 min.): • From the chart showing the effect on metal transfer by changes in shielding gas it is seen that an addition of 2% oxygen to tan argon GMAW using DCEP caused the arc to stop wandering and have good spray transfer. Can you explain from a physical point of view what might have happened?
Processes Using Constant Voltage Processes Using Constant Current • GMAW • FCAW • SAW • Processes that use constant velocity wire feeding • SMAW • GTAW • PAW • Processes where humans control arc length by hand
Questions? • Turn to the person sitting next to you and discuss (1 min.): • In the V-I Characteristic Curves, there are two places where the Arc current and voltage are the same as the power supply current and voltage, one point is stable and the other is unstable. Why is the unstable point unstable?
Heads Up Next Class Period You will Have a Homework Assignment which will require the use of an Excel Spreadsheet. You should review your knowledge of Excel or click on the digging deeper tutorial. Excel Tutorial