Physics of the Welding Arc | How the Arc Really Works

What actually happens inside a welding arc? In this video we break down the fundamental physics of the welding arc — from the initial gas discharge to the formation of a high-temperature thermal plasma. You will learn: • How the arc is ignited and maintained • The role of electrons and positive ions in the plasma column • Cathode and anode falls and why they matter • Temperature distribution inside the arc (4 000 – 25 000 K) • Metal vapour effects and the pinch effect • Why the arc characteristic has a falling and a rising region • Practical consequences for TIG, MIG/MAG and stick welding Based on the classic textbook “Schweißtechnik – Schweißen von metallischen Konstruktionswerkstoffen” by Prof. Dr.-Ing. habil. Klaus-Jürgen Matthes. This is essential knowledge for welding engineers, materials scientists, students and serious welders who want to understand the process beyond the surface. Timestamps: 0:00 Introduction 0:23 What is a welding arc? 1:16 Gas discharge and thermal plasma 3:52 Charge carriers – electrons & ions 7:52 Potential distribution in the arc 8:53 Temperature and conductivity 15:33 Magnetic effects and pinch 20:10 Summary & practical takeaways #Welding #ArcWelding #WeldingPhysics #Plasma #TIG #MIG #WeldingEngineering #MaterialsScience