Connection issues between flat copper tubes and steel plates in heat exchangers
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I would like to ask an expert: We manufacture heat exchangers for railway locomotives. Recently, our company entered into a partnership regarding heat exchangers with a company in the United States, but that company only supplies the core components without providing any technical support. We can only see the finished products, and have no idea about the manufacturing processes and methods used – it’s really frustrating. I wonder if any senior has come across something similar – namely, flat copper tubes (18.5*3.5*0.4) and steel plates (with a wall thickness of 13 mm). I would appreciate some advice. Thank you!
I think brazing might be used; ordinary flame brazing probably won’t work, as 0.4mm is too thin. Brazing in a high-temperature furnace should work.
Steel and copper can be welded together. The main difficulty in welding steel to copper and copper alloys is the tendency for cracks to form in the weld seam and the fusion zone. Practice has shown that in order to ensure the weld seam has sufficient crack resistance, the iron content in the weld seam should be ≤40%. Welding methods and welding materials: When welding low-carbon steel to copper and copper alloys, manual arc welding or tungsten inert gas welding can be used respectively. When welding low-carbon steel to pure copper, pure copper is used as the filler metal, such as electrode T107.