Oxy-Fuel Preheat Flame
The oxy-fuel preheat flame is a mixture of fuel gas and oxygen that heats the workpiece to the ignition temperature for the iron-oxygen combustion.
Physicochemical Mechanism of Action
The oxy-fuel preheat flame is created by mixing fuel gas (such as acetylene) with oxygen. This mixture burns at the right concentration and causes rapid heating of the workpiece to the ignition temperature for the iron-oxygen combustion.
Metallurgical Relevance & Welding Risks
Proper preheating is crucial to ensure a homogeneous weld seam. Insufficient preheating can lead to lack of fusion and weak spots, while overheating can distort or damage the workpiece.
Workshop Practice & Instructions
Use a mixture of 1 part oxygen to 3 parts fuel gas. The flame should be bright and clear. Hold the flame about 2–3 cm from the workpiece and move it slowly over the surface to ensure even heating.